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Students get through the MP Board Class 11th Biology Important Questions Chapter 18 Body Fluids and Circulation which are most likely to be asked in the exam.

MP Board Class 11th Biology Important Questions Chapter 18 Body Fluids and Circulation

Body Fluids and Circulation Class 11 Important Questions Very Short Answer Type

Question 1.
Which type of circulation is found in unicellular organisms?
Answer:
Unicellular organisms shows intracellular circulation. Cytoplasm of cell of the unicellular organism shows streaming movement called cyclosis. It helps in the circulation and distribution of materials in the cells e.g. Amoeba, Paramoecium etc.

Question 2.
What is known as heart block?
Answer:
Heart block : It is a condition in which bundle of His’ does not function properly then heartbeating impulse of atrial node does not reach ventricles, thus ventricle cannot exhibit their movement and thus circulation of blood is inhibited. This condition is called as heart block.

Question 3.
Where does the ‘Lubb’ and ‘Dup’ sounds are produced in Cardiac cycle?
Answer:
Lubb: ‘Lubb’ sound is produced during closure of atrioventricular valve (Bicuspid and Tricuspid valves). It is the first heart sound, which is low pitched but are of longer duration.
Dup : It is produced during closure of semilunar valves present at the base of arterial trunks. It is the second heart sound which is high pitched but of shorter duration.

Question 4.
Give reason that arteries are thick walled than that of veins.
Answer:
Arteries are thick walled than that of veins: When heart contracts blood enters into the arteries with great pressure as heart is responsible for supply of blood to each part of the body. To exert this pressure arteries are thick walled, whereas veins carry blood from different parts of the body to the heart without any pressure thus they are thin walled.

Question 5.
Write two functions of pericardial fluid.
Answer:
Two main functions of pericardial fluid are :
(i) It protects the heart from outer injuries,
(ii) It protects the heart from dryness.

Question 6.
Human heart is called myogenic. Why? (NCERT)
Answer:
Myogenic hearts are those where waves of contraction originate in special muscle fibres of heart.

Question 7.
What do you understand by double circulatory system? What is its significance? (NCERT)
Answer:
Double circulatory system: The circulatory system in which blood passes twice through heart for completing one cycle is called double circulatory system. In this type of circulatory system, oxygenated and deoxygenated blood flow remain separate. This type of circulation is found in all mammalian animals. In this system, first the deoxygenated blood is collected by veins into the heart and then it goes to the lungs for oxygenation. It returns to the left part of the heart and then to the body organs through arteries. Thus, the blood has to travel twice in the heart before it circulates in the body.

Question 8.
What is carboxyhaemoglobin?
Answer:
P-wave It is complex formed by the combination of haemoglobin with the CO₂. It provides blue colour to the blood in the vein.
Hb + CO₂ → Hbc

Question 9.
What are thrombocytes ? Where do they occur?
Answer:
In human blood, some irregular shaped cells are present which help in clotting of blood are called thrombocytes. They are formed in bone marrow.

Question 10.
In blood vessels, the flowing blood do not clot, why?
Answer:
In blood vessels, the flowing blood do not clot because in blood plasma, antiprothromb in, heparin named carbohydrate is present which takes the active thrombin to passive prothrombin direction due to which vessels do not clot.

Question 11.
What is pulse? What is the pulse rate of human beings?
Answer:
Beating of the heart is also felt in the surface arteries as regular jerk called as pulse. Each ventricular systole starts a new pulse, which proceeds as a wave of expansion through arteries, which is repeated after every 08 seconds.
It can be felt at the radial artery of wrist, temporal artery in front of the ear and carotid artery of the neck etc. Pulse rate of normal adult is 72 times per minute. In children, it is 120 times per minute and in old persons it is 60 times per minute.

Question 12.
How does partial pressure of respiratory gases control diffusion of oxygen from blood capillaries to the tissue?
Answer:
In the body tissue, P02 is very low that is about 40mm Hg, hence oxygen from arterial blood where P02 is about 95mm Hg. Thus oxygen separates from haemoglobin and diffuses into the tissues until the P02 goes down to 40mm Hg.

Question 13.
How does regulation of heartbeat occurs?
Answer:
The normal rate of heart beat is regulated by the following three ways :

1. Nervous control: Cardiac centre lies in the medulla of brain regulate heartbeat.
2. Hormonal control: Adrenalin and Noradrenalin hormone increases and decreases heart activity respectively.
3. Chemical control: Vagus nerve on stimulation secretes acetyl-choline which slows down the heartbeat while tip end of sympathetic nerve fibre secretes adrenalin, which accelerates heartbeat.

Question 14.
What is Heart sound?
Answer:
Various valves present at the inlet and outlet of ventricles regulate the flow of blood in the heart. Action of these valves, while closing the apertures, create the heart sound. Each heartbeat is accompanied by two heart sound ‘Lubb’ and ‘Dup’. It can be heard using a device called as stethoscope.

Question 15.
What is haemocoel?
Answer:
In higher invertebrates like arthropods and molluscs, open circulatory system is found. Blood vessels of them*are not divided into capillaries and open into write spaces called as sinuses in the body cavity, the blood fills in the body cavity and baths the organs. The body cavity filled with blood is called as haemocoel and the blood which is colourless called as haemolymph.

Body Fluids and Circulation Class 11 Important Questions Short Answer Type

Question 1.
Explain heart sound. (NCERT)
Answer:
Refer Q. No. 3 and 14 of Very Short Answer Type Questions.

Question 2.
Define Cardiac cycle and Cardiac output. (NCERT)
Answer:
Cardiac cycle: Contraction of the heart is called as Systole and relaxation of heart is called as Diastole. The sequence of one systole followed by one diastole is known as Cardiac cycle. It takes 0-8sec time to complete one cardiac cycle.
Cardiac output: At each heartbeat ventricle pump about 70ml blood. This volume is called as stroke volume. The heart beats 72 times per minute, which is known as heart rate. Quantity of blood pumped by the heart in one minute is called as cardiac output, i. e. 72 x 70ml = 5040ml blood per minute.

Question 3.
Where bicuspid, tricuspid and semilunar valves are present in human heart ? Write its functions.
Answer:
1. Bicuspid valve: The atrioventricular opening between left auricle and left ventricle is guarded by two flaps known as Bicuspid valve. It prevents backflow of blood.

2. Tricuspid valve: The right atrioventricular opening is guarded by three flaps known as tricuspid valve.

3. Semilunar valve: These are half-moon shaped flaps arising from the base of the pulmonary artery and aorta. A set of three semilunar valves guard the opening of right ventricle into pulmonary artery and another set is present where aorta arises from the left ventricle. All these valves present backflow of blood into ventricles.

Question 4.
Why blood is transported from auricles to ventricles during the relaxation of ventricles or ventricular diastole ?
Answer:
The volume of the ventricles is increased during the relaxation of ventricles and the inside pressure of it is low in comparison to the pressure of arteries. This will cause the closure of semilunar valves. Ventricles are remain in the position of relaxation even after closing of these semilunar valves.

Thus, lower pressure of their wall is maintained as it is. To balance this pressure aurio-ventricular valves are opened and blood flows from auricles to ventricles and fill up their cavity. After then ventricles contracts and thus the blood of its cavity is transported into arteries. Both of these processes (contraction and relaxation) occur alternatively.

Question 5.
What do you understand by blood pressure? Explain systolic and diastolic blood pressure.
Answer:
The pressure exerted on blood capillaries by pumping action of heart or by circulating blood of the body is called blood pressure.
Or
The force or pressure which the blood exerts on the walls of the artery in which it is contained is known as blood pressure.
Systolic pressure: Due to contraction of heart, blood is thrown out from the heart into artery which causes maximum blood pressure. This maximum pressure of blood in the blood capillary is called systolic blood pressure. The systolic pressure of a person is 120 mm Hg.

Diastolic pressure: The blood pressure of biood capillaries is minimum during the relaxation of ventricles. The minimum blood pressure of blood capillaries is called diastolic pressure. The diastolic blood pressure of an adult person is 80 mm Hg.

Question 6.
Where is sinoauricular node (SAN) situated? Why is SA node called pacemaker (speed motivator) of heart? (NCERT)
Answer:
Sinoauricular node (SA node) is situated in the upper part of right auricle of the heart. It is the site where heartbeat originates. It is also called as pacemaker or pacesetter. It is called pacemaker of the heart because cardiac rhythms commence here. When SA node does not function accurately the rate of heart beating will be irregular, slow or it stops. In this condition heart can not pump the blood according to requirement. In this condition artificial cardiac pacemaker is the substitute for a natural defective pacemaker which controls the beating of heart. Thus, SA node determines the rate of heartbeat and initiates it and so it is called as pacemaker of the heart.

Question 7.
Describe any four differences between sinoauricular and auriculo-ven- tricular node.
Answer:
Differences between S.A. Node and A.V. Node

Question 8.
Write differences between the following : (NCERT)
(a) Closed and Open Circulatory system
(b) Mitral value and Semilunar value.
Answer:
(a) Differences between Closed and Open circulatory system

(b) Differences between Mitral value and Semilunar value

Question 9.
Write any four differences between an Artery and a Vein.
Answer:
Differences between an Artery and a Vein

Question 10.
What are open and closed vascular system? Give two significance of closed vascular system.
Or,
What is closed vascular system?
Answer:
Open vascular system: The circulatory system in which blood flows indepen-dently in the coelomic cavity is called as open circulatory system.
Example: Cockroach.
Closed vascular system: The circulatory system in which blood flows through closed vessels.
Example: Earthworm, human.
Significance of closed vascular system :

1. Blood contains haemoglobin which helps to carry oxygen during respiration.
2. It helps in fast removal of excretory substance from the body.
3. Valves present in its blood vessels, prevents backward flow of blood.

Question 11.
Write differences between Blood and Lymph.
Answer:
Differences between Blood and Lymph

Question 12.
Give importance of Plasma protein. (NCERT)
Answer:
There are three plasma proteins :

1. Serum globulin,
2. Serum albumin,
3. Fibrinogen.

Functions or Importance of Plasma protein :
1. Immunity of the body: Globulin protein acts as antibody thus provide immunity to disease.
2. Prevent loss of blood by blood clotting: Fibrinogen and prothrombin are essential for clotting of blood.
3. Maintain fluidity of blood: Albumin and globulin possesses the ability to retain water in the blood plasma by their osmotic effects.
4. It helps for transport of protein and other substances.
5. It helps to maintain the pH of the blood.
6. It helps to maintain constant temperature of the body.
7. It helps to conduct heat.

Question 13.
Describe various components of blood and give one function of each component. (NCERT)
Answer:
Various component of blood and their functions :
Blood: Blood is a liquid connective tissue. Its matrix is liquid called as plasma. 90% of plasma is water in which various inorganic and organic substances are found in dissolved form. Three types of cells are found embedded in plasma called as corpuscles :
1. Erythrocytes or Red Blood Corpuscles (R.B.Cs.): These are biconvex, disc shaped, anucleated cells which contains a pigment haemoglobin. It helps to carry O₂ and CO₂ during respiration.

2. Leucocytes or White Blood Corpuscles (W.B.Cs.): These are nucleated, colourless, amoeboid cells. They are found in less number. They are of two types: It prevents the body from diseases by digesting and killing pathogenic germs.

3. Blood platelets: These are small, colourless, flat, granular, non-nucleated corpuscles, which helps for clotting of blood at injured part of the body.

Question 14.
Why blood is considered as connective tissue?
Answer:
Group of cells which are similar in their structure, function and origin are called as tissue.
Structurally blood is similar to connective tissue as it has a liquid matrix called as plasma in which various types of blood cells, RBCs, WBCs and Blood platelets are found in scattered form. It is also functionally similar to connective tissue as it connects all parts of the body by transporting materials. Thus blood is called as liquid connective tissue.

Body Fluids and Circulation Class 11 Important Questions Long Answer Type

Question 1.
Write differences : (NCERT)
(a) Blood and Lymph
(b) Open and Closed Circulatory System
(c) Systole and Diastole
(d) P-wave and T-wave.
Answer:
(a) Differences between Blood and Lymph

(b)
(a) Differences between Closed and Open circulatory system

(b) Differences between Mitral value and Semilunar value

(c) Differences between Systole and Diastole

(d) Differences between P-wave and W-wave

Question 2.
Draw a Unit of ECG and explain its various segments. (NCERT)
Answer:
Electrocardiogram (ECG): A graphic record of the electrical variations produced by the beating of the heart is called electrocardiograph. These variations are due to the development of electrical negativity of excited muscles as compared with unexcited tissues. An instrument used to observe the working of the heart is called electro-cardiogram. It was discovered by Einthoven (1906).

ECG is formed by a series of ridges and furrows. Normal pattern of ECG for a healthy person is given below.
In this, ‘P’ wave indicates the impulse of contraction generated by S.A. node. ‘QRS’ wave indicates the spread of impulse of contraction from A. V. node to the wall of ventricles, whereas the ‘T’ wave represents the relaxation of ventricles.
Any abnormality in the working of the heart changes the wave pattern of ECG and can be interpreted by a trained physician to diagnose a particular disorder. The technique to detect the abnormalities of the heart with the help of ECG is called electrocardiography.

Question 3.
Give reasons of following :
(a) Arteries are thick walled than that of veins.
(b) Doctors give injection in the veins.
(c) Veins are provided with valves but not arteries.
(d) Veins are blue coloured whereas arteries are red in colour.
Answer:
(a) Arteries are thick walled than that of veins: When heart contracts blood enters into the arteries with great pressure as heart is responsible for supply of blood to each part of the body. To exert this pressure arteries are thick walled, whereas veins carry blood from different parts of the body to the heart without any pressure thus they are thin walled.

(b) Doctors give injection in the veins: Doctors give injection in the veins because they are found in the surface of the body and carries blood to the heart, from where medicine can be distributed to all parts of the body through arteries.
But if doctors will give injection to the arteries then medicine will reach to particular part only.

(c) Veins are provided with valves but not arteries: Veins carries blood from dif-ferent part of the body to the heart without any pressure thus in order to prevent backward flow of blood and to direct the blood towards the heart, veins are provided with valves. Whereas arteries carry blood from heart to different parts of the body with pressure thus blood can easily reach to all parts of the body. Therefore arteries are not provided with valves.

(d) Veins are blue coloured whereas arteries are red in colour: Outer wall of the vein consists of tunica externa. Cells of this layer contain a pigment substance which reflect blue light thus veins appears blue whereas such pigments are not found in the wall of the arteries. Thus, arteries appears red coloured due to presence of blood in it, which reflect red light.

Question 4.
Give reasons of following statements :
(a) Wall of the left ventricle is more thick as compared to the wall of the right ventricle.
(b) Wall of the left ventricle is thick as compared to the auricles.
(c) Lymph contains less protein as compared to the plasma.
(d) Closed circulatory system is better as compared to the open circulatory system.
(e) During systole ventricles of the heart becomes a closed chamber.
Answer:
(a) Wall of the left ventricle is more thick as compared to the wall of the right ventricle : Right ventricles contains impure blood. To pass blood to the pulmonary artery less pressure is required by the right ventricle whereas to send blood to cortico sys-temic aorta more pressure is required by the left ventricle thus wall of the left ventricle is thicker than that of right ventricle.

(b) Wall of the left ventricle is thick as compared to the auricles : Left ventricle is responsible for the supply of blood to all parts of the body through cortico systemic aorta thus more pressure is required by it where as auricle receives blood without any pressure. Therefore left ventricle is thick walled as compared to the auricles.

(c) Lymph contains less protein as compared to the plasma : Capillaries found in the lymph are impermeable thus plasma protein quantity of lymph is less as compared to the blood.

(d) Closed circulatory system is better as compared to the open circulatory system:
In open circulatory system blood do not flow through closed vessels. Blood is found in the haemocoel cavity and is direct in contact of the organs. Blood pressure in this system is very less, e.g. Cockroach. In closed circulatory system blood is enclosed by heart, arteries and veins. Blood flows fast through these vessels and come back to the heart.

In this way exchange of substances between blood and tissue occurs fast. Whereas in open circulatory system this type of regulation is not found, thus closed circulatory system is considered as best as compared to the open circulatory system.

(e) During systole ventricles of the heart becomes a closed chamber : During ventricular systole pressure of the ventricle is more than that of auricles. Thus when blood reaches to the ventricle from auricles auriculoventricular valves closes the auriculo-ven- triculi aperture and prevents backward flow of blood. As ventricular pressure is less than the pressure of pulmonary artery thus semilunar valves remain closed, thus ventricle con-tracts as a closed chamber.

Question 5.
Who can donate blood to whom, also write the precautions of blood donation?
Answer:
Blood transfusion depends mainly on blood group. Therefore :
1. A blood group can be donated to person with blood group type A and AB.
2. Person with blood group B can donate blood to person with blood group type B or AB.
3. Person with AB group can donate blood only to person with AB blood group.
4. Blood group O is called universal donor but he can receive blood of only group O type.
Similarly the persons with blood group AB are called universal recipient as they can receive blood from persons with any blood group type.

Precautions of blood donation :
1. The first and the foremost precaution for donation of blood is testing the blood groups of both the donor and the recipient so that the problem of agglutination can be avoided.

2. Many fatal diseases get transmitted through blood. Thus, the donor’s blood should be tested for the presence of HIV and Hepatitis virus and getting negative result should be confirmed before transfusion.

3. Only upto 500 ml of blood should be donated by a man at one time.
4. Blood should not be donated more than twice in one year.
5. Donor should be completely healthy.
6. Equipments used in the process of transfusion should be thoroughly sterilized before use.

Question 6.
What is Hepatic portal system?
Answer:
Generally after collecting deoxygenated blood veins pour the blood into heart. But some veins pour blood into some other organs before reaching to heart for its purification. There veins are called as portal veins, and the system formed by these veins is called as portal system.

Hepatic portal system of man : When portal veins carry blood to the liver instead of heart and then through some other veins from liver to heart, it is called as Hepatic portal system.
Hepatic portal veins of human collect blood from different parts of the alimentary canal and carry it to liver. From liver through hepatic vein blood reaches to post caval.
Hepatic portal system consists of following veins :

1. Lineogastric vein: It collects blood from all wall of the stomach and spleen.
2. Duodenal veins: It collects blood from duodenum.
3. Anterior mesenteric vein: It collects blood from small intestine, caecum and colon.
4. Posterior mesenteric vein: It collects blood from rectum and anus.

Question 7.
Describe the structure of mammalian heart.
Or,
Describe structure and mechanism of working of mammalia heart.
Or,
Draw a well labelled diagram of L.S. of heart.
Answer:
Structure of Human Heart:
Position and external structure of human heart: The mammalian heart including man is a hollow, cone-shaped, muscular structure that lies in the thoracic cavity above the diaphragm and in between the two lungs. It is about the size of a fist measuring about 12 cm in length and 9 cm in breadth. It’s weight is about 300 grams. It is four-chambered organ, having two auricles and two ventricles.

Heart lies in cavity called as Pericardium cavity. Pericardium cavity is surrounded by double membrane and is filled with pericardial fluid, which prevent the heart from external jerk, friction and keeps the heart moist.

Internal structure of human heart: The auricles are thin walled, sac like structures. The right and left auricles are separated from each other by a longitudinal muscular partition, called interauricular septum. The anterior and posterior vena cava open by separate apertures in the right auricles. The pulmonary veins open into left auricle by single common opening. The cavity of the ventricle is also divided into two by a thick and muscular interventricular septum. The wall of the left ventricle is much thicker than that of the right. The cavity of the left ventricle is circular while that of right is crescentic in outline in transverse sections. The right auricle opens into the right ventricle by a wide aperture called right auriculoventricular aperture. Similarly, the left auricle opens into the left ventricle by means of a large opening known as left auriculoventricular aperture.

The right auriculoventricular aperture is guarded by a valve which is formed of three flaps or cusps. This valve is called right auriculoventricular valve or tricuspid valve. The left auriculoventricular aperture is provided with a valve which has two cusps. It is known as left auriculoventricular valve or bicuspid valve or mitral valve. When the ventricles contract, both these valves close so that the blood is prevented from going back into the auricles from the ventricles. These valves are attached to columnae carnae or papillary muscles on the inner wall of the ventricles by means of thin threadlike structures called choradae tendinae.

The walls of the ventricles are much thicker than those of the auricles and are highly muscular. A special type of muscles are grouped together on the top of the interventricular septum to form a structure called Bundle of His or atrioventricular bundle. From the left anterior part of right ventricles arises the pulmonary arch which curves towards the left side of the heart passing below the carotid-systemic arch and goes to the lungs from the dorsal side of the heart.

Three semilunar valves are present at the origin of the pulmonary arch. These valves do not allow the blood to go back into the right ventricles. The aorta or carotid-systemic arch arises from the right anterior part of the left ventricle. This arch passes over the pulmonary arch to come over the dorsal side of the heart where it forms the dorsal aorta below the vertebral column. These semilunar valves are also present at the origin of this arch to check the backflow of the blood into the left ventricle.
Mechanism of working of Human heart:

Mechanism of human heart: The rhythmic contraction and relaxation of the auricles and ventricles of heart in a specific sequence is called heart beat. The contraction phase is called as systole and the relaxation phase is called diastole.
The systole and the diastole together constitute a heart beat. The movement of the auricles and the ventricles are repeated in a cyclic manner during each heart beat. The amount of blood ejected by each ventricle per stroke at rest is about 70-90 ml. The volume of blood is termed as the stroke volume. This leaves about 50 ml of blood in each ventricle at the end of a systole and is known as end-systolic ventricular blood volume.

The human heart beats about 72 times a minute and this is termed as heart rate. The stroke volume when multiplied by the heart rate gives the volume of blood pumped out by each ventricle per minute. This volume is referred to as cardiac output.

Cardiac cycle: The atrial and ventricular systole and diastole which occur during each complete heart beat is called a cardiac cycle. This happens for a specific duration and the blood flows through the heart in a specific direction. The duration of each cardiac cycle at a heart rate of 75 per minute is 0-80 seconds in which the duration of systole is 0-27 seconds and that of diastole is 053 seconds.

Late diastole: In the late diastole the bicuspid and the tricuspid valves between the auricles and ventricles are opened and the semilunar valves at the entrance of aorta and pulmonary artery are closed. Blood flows into the heart throughout diastole, filling the auricles and ventricles. The rate of filling declines as the ventricles become distended and the cusps of the A.V. valves drift toward the closed position.

Atrial systole: Over two-thirds of the ventricular filling occurs passively during dias-tole. Contraction of the auricles propels some additional blood into the ventricles. The con-traction of the atria is called atrial systole. Contraction of the atrial muscles that surrounds the orifices of the vena cava and pulmonary veins blocks their opening and so the atrial blood cannot pass back from the atria into these vessels, but there is some regurgitation of blood into the veins during atrial systole.

Ventricular systole : The simultaneous contraction of both the ventricles is called ventricular systole. The initial portion of ventricular systole is called isometric or isovolumetric ventricular contraction which lasts until the aortic and pulmonary valves open. The A.V. valves close at the start of isometric contractions. Intraventricular pressure rises rapidly and the ventricular ejection begins. Ejection is rapid at first, slowing down as the systole progresses.

Diastole: The relaxation of the heart chambers after the systole is called diastole. When the ventricles start contracting, the atria start the atrial diastole. During the atrial diastole the blood through the veins flows into the atria. At the end of ventricular systole, the ventricles start the ventricular diastole. Towards the end of a joint diastole a new cardiac cycle begins with the atrial systole.

Question 8.
Describe mechanism of human heart.
Answer:
Mechanism of human heart: The rhythmic contraction and relaxation of the auricles and ventricles of heart in a specific sequence is called heart beat. The contraction phase is called as systole and the relaxation phase is called diastole.
The systole and the diastole together constitute a heart beat. The movement of the auricles and the ventricles are repeated in a cyclic manner during each heart beat. The amount of blood ejected by each ventricle per stroke at rest is about 70-90 ml. The volume of blood is termed as the stroke volume. This leaves about 50 ml of blood in each ventricle at the end of a systole and is known as end-systolic ventricular blood volume.

The human heart beats about 72 times a minute and this is termed as heart rate. The stroke volume when multiplied by the heart rate gives the volume of blood pumped out by each ventricle per minute. This volume is referred to as cardiac output.

Cardiac cycle: The atrial and ventricular systole and diastole which occur during each complete heart beat is called a cardiac cycle. This happens for a specific duration and the blood flows through the heart in a specific direction. The duration of each cardiac cycle at a heart rate of 75 per minute is 0-80 seconds in which the duration of systole is 0-27 seconds and that of diastole is 053 seconds.

Late diastole: In the late diastole the bicuspid and the tricuspid valves between the auricles and ventricles are opened and the semilunar valves at the entrance of aorta and pulmonary artery are closed. Blood flows into the heart throughout diastole, filling the auricles and ventricles. The rate of filling declines as the ventricles become distended and the cusps of the A.V. valves drift toward the closed position.

Atrial systole: Over two-thirds of the ventricular filling occurs passively during dias-tole. Contraction of the auricles propels some additional blood into the ventricles. The con-traction of the atria is called atrial systole. Contraction of the atrial muscles that surrounds the orifices of the vena cava and pulmonary veins blocks their opening and so the atrial blood cannot pass back from the atria into these vessels, but there is some regurgitation of blood into the veins during atrial systole.

Ventricular systole: The simultaneous contraction of both the ventricles is called ventricular systole. The initial portion of ventricular systole is called isometric or isovolumetric ventricular contraction which lasts until the aortic and pulmonary valves open. The A.V. valves close at the start of isometric contractions. Intraventricular pressure rises rapidly and the ventricular ejection begins. Ejection is rapid at first, slowing down as the systole progresses.

Diastole: The relaxation of the heart chambers after the systole is called diastole. When the ventricles start contracting, the atria start the atrial diastole. During the atrial diastole the blood through the veins flows into the atria. At the end of ventricular systole, the ventricles start the ventricular diastole. Towards the end of a joint diastole a new cardiac cycle begins with the atrial systole.

Question 9.
How does normal heart beating is regulated?
Or,
What do you mean by S.A. node and A.V. node? Explain their functions.
Answer:
S.A. node and A.V. node : The normal rate of heart beating is regulated by a group of tissues situated on the upper part of the right atrium, these groups of tissues are called as the sinoauricular node (S.A. node). S.A. nodes are also called as the controller of heart beating. A similar node called as auriculo-ventricular node (A.V. node) is also found on the septum of atrium and ventricle. Both of these nodes are made up of muscles, nerve fibres and nerve cells. Two branches arising from A.V. node and enter the ventricles. These branches are called as bundle of His or Purkinje fibres.

Function of S.A. node and A.V. node or regulation of normal heart beating: The impulse to contract originates from S.A. node. Thus this area is called as pacesetter of the heart. The impulse from the S.A. node then passes in a wave like manner over the atria and it is collected at another area called A.V. node. Thus the impulses travels up to the ventricles. Blood from the various part of the body enters the right atrium and from lungs to the left atrium. Which then contracts sending the blood to the respective ventricles. Now the right ventricle contract with the result A. V. aperture is closed by three valves and the blood passes into the pulmonary artery and cortico-systemic aorta.

The action of S.A. node is controlled by a controlling centre known as cardiac centre. There are two parts in cardiac centre. First part is known as cardioinhibitor, send their impulse to the S.A. node whereas second part send their impulse into S.A. node through sympathetic nerves. First part decreasing the rate of heart beat whereas second part increasing it. Some hormones and chemicals like thyroxin, adrenalin and acetyl choline are also affecting the rate of heart beating.

Question 10.
What do you mean by double circulation ? Explain.
Or,
Explain mechanism of double circulation.
Answer:
Double circulation: Circulation in which blood flows twice through the heart is called as double circulation. At first heart receives deoxygenated blood from vena cava then send the blood to the lungs for purification through pulmonary arteries. After purification blood is received by heart again through pulmonary vein and then through aorta oxy-genated blood is distributed to whole parts of the body. In double circulation two circulations are found :

1. Systemic circulation,
2. Pulmonary circulation.

1.Systemic circulation: Vertebrates have a closed blood vascular system. The continuous flow of blood within the system is maintained by the regular rhythmic pumping action of heart. The left ventricle ejects blood into the aorta. Aorta through its branches supply blood to various organs of the body. After the exchange of gases the deoxygenated blood returns to the heart through a large number venules, veins and ultimately to the superior and inferior vena cava. This circulation is known as systemic circulation.

2. Pulmonary circulation: The right ventricle on contraction pumps blood into the pulmonary artery which carries the deoxygenated blood to the lungs. After the oxygenation process blood returns to the left atrium through two pairs of pulmonary veins. This circulation is known as pulmonary circulation.

Question 11.
Describe various heart diseases of man in brief.
Answer:
Heart diseases in man: General symptoms of heart diseases include breathlessness, ankle swelling, liver congestion, dry cough, fatigue and difficulty in lying down. The diseases are described below :

1. Arteriosclerosis: In this disease arteries and arterioles lose their elasticity. This loss of elasticity is due to deposition of cholesterol or calcium and thickening of the fibrous tissue in the inner lining of blood vessels. As a result the lumen of the arteries becomes narrow. High blood pressure and cerebral haemorrhage are the common disease symptoms.
2. Coronary heart diseases : A set of coronary arteries supply blood to the heart muscle. When they become hard and narrow, blood supply to heart is reduced. The affected person feels severe pain in the chest along the arms. Sometimes a clot may develop and stop the blood supply to the heart. This is called coronary thrombosis. Nitroglycerine tablets relax the arteries and thus reduce the pain. Heparin and dicumarol prevent blood clotting and promote its smooth flow.

3. Rheumatic heart: The disease is caused by the inflammation of the heart. It may affect:

• Inner lining of the heart including valves: It is called endocarditis.
• Outer covering of the heart: It is called pericarditis.
• Heart muscles: It is called myocarditis.

Inflammation may cause permanent damage to heart. Usually, it is followed by the’ infection of streptococci bacteria. The bacteria release the toxin which travels to the joints to cause rheumatic fever, i.e. swelling and pain in legs and fever.
Rheumatism causes permanent damage to heart in two ways :

1. Opening of the valves is narrowed and
2. Valves do not close properly. Both of these defects hinder the free flow of blood in the required direction.
3. Low blood pressure, joints swelling and pain in legs and fever are the typical symptoms. Bed rest is advised.

4. Hypertension: When a person suffers from nervous tension or emotional stress such as fear, worries, anxieties etc. they show high blood pressure because the walls of their arteries get contracted. This is hypertension. If such a stress is frequently found then it results in a persistent high blood pressure.

During this phase heart has to work harder to pump blood to different parts of the body. This may sometimes lead to destruction of the arteries of kidney causing chronic nephritis. Headache, dizziness, fatigue, restlessness are the typical symptoms of hypertension. Chlorothiazides are given as medicines. Bed rest, exercise and avoidance of alcoholism and smoking are advised.

5. Ventricular fibrillation: In this disease each part of ventricles contracts at different time.
6. Angioma: Due to formation of blood clot in the coronary artery, heart wall do not get sufficient supply of blood and causes severe chest pain.

7. Myocardial infraction or Heart attack: Due to obstruction in the coronary artery heart muscle do not get sufficient blood due to which the cells damage and fails to function properly. This condition is called as myocardial infarction or heart attack.

Body Fluids and Circulation Class 11 Important Questions Objective Type

1. Choose the correct answers:

Question 1.
S. A. node is found in :
(a) Alimentary canal
(b) Aorta
(c) Liver
(d) Heart.
Answer:
(d) Heart.

Question 2.
Sphygmomanometer is used for the measurement of:
(a) Blood pressure
(b) Rate of heartbeat
(c) Rate of blood flow
(d) Temperature.
Answer:
(a) Blood pressure

Question 3.
Blood platelets are concerned with :
(a) Transport of CO₂
(b) Release of antitoxins
(c) Production of antibodies
(d) Release of thromboplastin.
Answer:
(d) Release of thromboplastin.

Question 4.
In which form the CO₂ is carried out by the blood :
(a) Sodium carbonate
(b) Sodium bicarbonate
(c) Potassium carbonate
(d) Magnesium bicarbonate.
Answer:
(b) Sodium bicarbonate

Question 5.
An antibody is :
(a) A molecule that specifically inactivates an antigen
(b) W.B.Cs. which invade bacteria
(c) Secretion of mammalian R.B.Cs.
(d) Component of blood.
Answer:
(a) A molecule that specifically inactivates an antigen

Question 6.
Carotid artery carries :
(a) Impure blood from brain
(b) Oxygenated blood to anterior region of body or to brain
(c) Impure blood to kidney
(d) Oxygenated blood to heart.
Answer:
(b) Oxygenated blood to anterior region of body or to brain

Question 7.
During diastole :
(a) Blood enters lungs
(b) Blood leaves the ventricle
(c) Blood leaves the heart
(d) Blood enters the heart.
Answer:
(d) Blood enters the heart.

Question 8.
Heart beat is regulated by the cranial nerve :
(a) Xth
(b) IXth
(c) find
(d) Vth.
Answer:

Question 9.
What is blood bank in human body :
(a) Spleen
(b) Lungs
(c) Heart
(d) Liver.
Answer:
(a) Spleen

Question 10.
Average cardiac output is :
(a) 4 litre per minute
(b) 63 litre per minute
(c) 5-3 litre per minute
(d) 73 litre per minute.
Answer:
(c) 5-3 litre per minute

Question 11.
Rh factor is a protein present:
(a) On R.B.Cs.
(b) In plasma
(c) On W.B.Cs.
(d) In serum.
Answer:
(a) On R.B.Cs.

Question 12.
During systole of ventricle:
(a) Blood enters the heart
(b) Blood leaves the heart
(c) Blood leaves the ventricle
(d) Blood enters lungs.
Answer:
(c) Blood leaves the ventricle

Question 13.
Pure blood (Oxygenated) is formed in:
(a) Pulmonary vein
(b) Renal vein
(c) Hepatic portal vein
(d) Pulmonary artery.
Answer:
(a) Pulmonary vein

Question 14.
The life of R.B.Cs. is:
(a) About 120 days
(b) 90 days
(c) 30 days
(d) 10 years.
Answer:
(a) About 120 days

Question 15.
Where is chordae tendineare found in the heart:
(a) Ventricle
(b) Left Ventricle
(c) Right Auricle
(d) None.
Answer:
(a) Ventricle

Question 16.
William Harvey is famous for the discovery of :
(a) Respiration
(b) Blood contraction
(c) Blood circulation
(d) digestion.
Answer:
(c) Blood circulation

Question 17.
Which part of vertebrate is responsible for pure blood:
(a) Gill
(b) Lungs
(c) Spleen
(d) Liver.
Answer:
(c) Spleen

Question 18.
Spleen is:
(a) Haemopoitic
(b) Lymphide
(c) Reproductive
(d) None.
Answer:
(b) Lymphide

Question 19.
Which structure of human when not working properly is replaced by pacemaker:
(a) S. A. node
(b) A.V. node
(c) Both (a) and (b)
(d) None.
Answer:
(a) S. A. node

Question 20.
Which instrument is used for measuring blood pressure :
(a) Stethoscope
(b) Electrocardiograph
(c) Sphygmomanometer
(d) None.
Answer:
(c) Sphygmomanometer

Question 21.
Which vitamin help for clotting of blood :
(a) Vitamin-E
(b) Vitamin-K
(c) Vitamin-C
(d) Vitamin-D.
Answer:
(a) Vitamin-E

Question 22.
Which blood cells kills pathogenic germs in the blood :
(a) Platelets
(b) Red blood corpuscles
(c) White blood corpuscles
(d) Skin cells.
Answer:
(c) White blood corpuscles

Question 23.
Hormone which regulate heartbeat and blood pressure :
(a) Thyroxin
(b) Adrenalin
(c) Gastrin
(d) Secretin.
Answer:
(b) Adrenalin

Question 24.
Where sinu-auricular node is located :
(a) In the Brain
(b) In the Liver
(c) In the Spleen
(d) In the Heart.
Answer:
(d) In the Heart.

2. Fill in the blanks:

1. The number of chambers in the heart of amphibian is ……………………………………. whereas number of chambers in human heart is ……………………………………. .
Answer:
Three, four,

2. ……………………………………. vascular system is found in sponges.
Answer:
Water,

3. Neurogenic heart is found in ……………………………………. .
Answer:
Invertebrates,

4. The oxygenated blood from lungs reaches left atrium of heart through ……………………………………. .
Answer:
Pulmonary artery,

5. Formation of blood is called ……………………………………. .
Answer:
Haemopoisis,

6. Pericardium is ……………………………………. layered.
Answer:
Two,

7. ……………………………………. is a lymphatic organ.
Answer:
7. Spleen,

8. ……………………………………. heart is found in mammals.
Answer:
8. Myogenic,

9. Blood cells are produced in the ……………………………………. .
Answer:
Bone marrow,

10. ……………………………………. is not found in human RBCs.
Answer:
Nucleus.

3. Match the following:

(A)

Answer:
1.  (c) A.V. Bundle,
2. (d) Pacemaker
3. (b) Systematic circulation
4. (e) Semiluner valve.
5. (a) AV. node.

(B)

Answer:
1.  (e) Four chambered.
2. (d) Three chambered
3. (a) Nerve fibre
4. (b) Spleen
5. (c) Left atrium and left ventrium.

(C)

Answer:
1.  (c) Prevent infection,
2.  (e) Transport of respiratory gas.
3. (b) Universal recipient
4.  (a) Blood clotting
5. (d) Contraction of heart.

4. Answer in one word:

1. Where does dub and lub sounds are produced in cardiac cycle.
Answer:
When auricle contracts, ventricle relax

2. Name the sounds produced due to following actions:
(a) Closing of atrio ventricular valve and initiation of ventricular contraction.
(b) Closing of semilunar valves and initiation of contraction of ventricle.
Answer:
Lub, dub,

3. What is carbaminohaemoglobin?
Answer:
Haemoglobin + CO₂,

4. Write the pulse rate of human.
Answer:
72 times per minute,

5. How many types of circulatory systems are found in animals?
Answer:
Two, Open and closed circulatory system,

6. Name the instrument meant for recording heartbeat?
Answer:
Electrocardiogram (ECG),

7. Where are Purkinje fibres situated?
Answer:
Auricular ventricular node (A.V.Node),

8. What is the blood pressure of a normal adult human being?
Answer:
120/80 mm Hg.,

9. Thrombocytes are present in which part of human body?
Answer:
Blood platelets,

10. Why blood is red in colour?
Answer:
Due to Haemoglobin

11. What is blood pressure of a normal man?
Answer:
120/180.

Students get through the MP Board Class 11th Biology Important Questions Chapter 19 Excretory Products and their Elimination which are most likely to be asked in the exam.

MP Board Class 11th Biology Important Questions Chapter 19 Excretory Products and their Elimination

Excretory Products and their Elimination Class 11 Important Questions Very Short Answer Type

Question 1.
Define Glomerular filtrate rate (GFR). (NCERT)
Answer:
Quantity of glomerular filtrate or Nephric filtrate filtered per minute by the kidney of human is called as Glomerular filtrate rate (GFR).
Rate of filtration in a normal adult person is about 125ml per minute.
[Average volume of GF per day by the kidney is 190 litres.]

Question 2.
Write the name of excretory organs of following phylum animals :
(a) Protozoa,
(b) Coelenterates,
(c) Molluscs,
(d) Arthropods
(e) Annelida.
Answer:
(a) Protozoans : Plasma membrane, contractile vacuoles.
(b) Coelenterates: Diffusion by plasma membrane.
(c) Molluscs: Renal organs or kidney.
(d) Arthropodes : Malphighian tubules.
(e) Annelida : Nephridia for excretion.

Question 3.
Write the name of hormone which causes Addison’s disease.
Answer:
Mineralocorticosteriod hormone is responsible to increase the amount of water and sodium in urine. This disease is called Addison’s disease.

Question 4.
How does human skin and lungs function as an excretory organ?
Answer:
Human skin possesses sebaceous glands and sweat glands. These glands excrete some excretory substances with their secretion like sebum and sweat. Hence, skin is also called as excretory organ.
Lungs help for excretion by exhalation of CO₂ from the body.

Question 5.
Why the excretion of uric acid in place of urea is more advantageous for birds and reptiles?
Answer:
Uric acid and their salts are relatively less harmful and water-insoluble, hence they are excreted in the form of solids and thus, water is not lost whereas, water is also lost in the excretion of urea. Thus, the excretion of uric acid in birds and reptiles is a mode of adaptation to prevent water loss.

Question 6.
In which part of body ammonia is converted into urea?
Answer:
Liver.

Question 7.
Explain the significance of ureotelism in ureotelic animals.
Or,
What is ureotelism? How it is advantageous over other excretions?
Answer:
Ureotelism is the urinary elimination of nitrogenous waste products mainly in the form of urea. Urea is relatively less harmful waste product in the nature. However urea is very soluble in water. Therefore, the ureotelic animals must be able to afford sufficient amount of water for excretion (in aquatic animals) concentrate urine (in Kangaroo and Rat) or retain considerable amount of urea in body fluids and blood (in Shark). Thus, this phenomenon is a type of adaptation in these animals.

Question 8.
What will be the ‘affect, if deamination process in the liver of human is stopped?
Answer:
If deamination process in the liver is stopped then conversion of ammonia into urea for its removal will stop. Excess amino acid reaches to the liver will fail to convert into carbohydrates by removal of amino group, as a result of which formation of pyruvic acid and ammonia will stop. Due to collection of toxic substances, other life activities will be affected.

Question 9.
Write the name of: (NCERT)
(a) One vertebrate in which excretion occurs through flame cells.
(b) Part of the kidney which lies embedded in between renal pyramids of medulla.
(c) Network of capillaries found surrounding Henle’s loop.
Answer:
(a) Planaria,
(b) Renal column of Bertini,
(c) Vasa recta.

Question 10.
What is Osmoregulation? (NCERT)
Answer:
The process by which osmotic pressure of the body fluids are maintained by addition or elimination of various substance like water, salt etc. is called as Osmoregulation.

Excretory Products and their Elimination Class 11 Important Questions Short Answer Type

Question 1.
Explain self regulation mechanism of Glomerular filtrate rate (GFR). (NCERT)
Answer:
Regulation of Glomerular filtrate rate (GFR) is done by ultrafiltration through glomerular capillaries, which is located at the joining of the afferent and efferent arterioles. Fall in glomerular filtrate rate induce glomerular capillaries to secrete renin, which activate renal blood circulation, thus again glomerular filtrate rate (GFR) become normal.

Question 2.
Describe Countercurrent mechanism in brief.
Answer:
Mammal excretes hypertonic urine. Henle’s loop and Vasa recta plays an important role, for this Vasa recta are in the form of loops, surrounding Henle’s loop, hence blood flows in opposite direction in the two limbs of each Vasa recta, the blood flowing in the descending limb comes closer to the outgoing blood in the ascending limb, this is called Counter current system.

Na⁺ and Cl^– are reabsorbed from the filtrate in ascending limb and subsequently released into the surrounding medullary tissue and retained by the vasa recta. This limb is impermeable to water. Thus, urine become progressively more hypotonic but the descending loop of Henle wall is permeable to water thus more water is reabsorbed by its wall and urine become hypertonic.

Question 3.
Generally terrestrial organisms excrete urea or uric acid not ammonia. Why? (NCERT)
Answer:
Sufficient water is not available for terrestrial animals for speedy elimination of ammonia. So, it is converted into urea in the liver or into uric acid.
Urea is less toxic than ammonia and requires less water for elimination from the body. Urea is excreted as urine, e.g., mammals, amphibians like frog, toad etc.

whereas in reptiles and birds ammonia is converted into uric acid, which is least toxic nitrogenous waste product and requires very little amount of water for elimination. In the cloaca of reptiles and birds, uric acid accumulates and further concentrated there and passes out the body as whitish semisolid crystal form. Actually, this is adaptation in terrestrial organisms due to their dry habitat.

Question 4.
Explain urination. (NCERT)
Answer:
Urination or Micturition: The process of excretion of urine out of the body from the urinary bladder when it gets filled is called as urination or micturition. A normal healthy man excrete 1 to 1 -5 litres of urine per day.
It is controlled by the nervous mechanism. When sufficient pressure is built up in the bladder, a spontaneous nervous activity is generated due to which smooth muscles of the bladder wall contract and the urethral sphincter are relaxed. As a result, urine comes out from the bladder through urethra.

Note: In adults, the sphincter opens only when it is convenient to urinate otherwise it remains closed even when the pressure inside the bladder is high. The act of urination may be both voluntary and involuntary, but voluntary control develops late.

Question 5.
Give importance of Liver, Lungs and Skin in excretion. (NCERT)
Answer:
1. Liver: Liver plays chief role in excretion. It converts the excessive amount of amino acids present in blood into ammonia and pyruvic acid in their oxidative deamination.
Pyruvic acid oxidizes to release energy while amino acids are converted into less harmful substance, the urea which is filtered from the blood by kidney. This urea is then released with urine.

Urea
Liver also separates dead R.B.Cs. from the circulatory system and also converts its haemoglobin into useful bile salts.
Liver also converts the cholesterol, skatol and indole into less harmful substances and then mixes them in circulatory system. Kidney filters these substances from the blood.

2. Skin or integument: In aquatic animals where excretory organs are not developed, excretion takes place through general body surface (integument) by the process of diffusion. Mainly ammonia is excreted out into the surrounding water by this process. Higher animals like mammals including man possess two types of glands in their skin, sebaceous glands and sweat glands.

3. Lungs: Lungs help to eliminate the excretory waste products like carbon dioxide and some water in the form of vapour.

Question 6.
Give importance of Juxtra medullary tubules in function of kidney. (NCERT)
Answer:
30% Nephrons of the kidney has longer size of Henle’s loop. These nephrons are called as Juxtra medullary tubule. These tubules plays an important role in concentration mechanism of urine. When there is deficiency of water in the body vasopressin hormone is secreted, which induces reabsorption of water by the wall of the descending loop of Henle of extramedullary tubule. As a result of which more and more water is reabsorbed and hypertonic urine is produced. This mechanism of concentration of urine is called as counter current mechanism.

Question 7.
How the permeability of distal convoluted tubule and collecting tubule is controlled due to which the amount of water in the body is maintained?
Answer:
When the amount of water in our body is increased then nephrons absorb it from blood and dilute it. But when the amount of water in our body is decreased then nephrons or renal tubules absorb least amount of water and thus, the amount of urine is also decreased and urine becomes concentrated. Changes in the nature of urine resulting due to changes in the permeability of distal convoluted tubules and collecting tubules and their permeability is controlled by hormones.

The first hormone is aldosterone, that increases the process of reabsorption of Na⁺ from the filtrate of renal tubules and thus the amount of Na⁺ is also maintained. Second hormone is vasopressin which controls the dilution and concentration of urine. Hormone aldosterone is formed from the cortex of adrenal gland and the vasopressin hormone is secreted by posterior lobe of pituitary gland.

Question 8.
Draw a well labelled diagram of nephron of human.
Answer:

Question 9.
Describe any four functions of kidney.
Answer:
The chief function of kidney is to excrete the nitrogenous excretory substances out of the body. In addition to excretion kidney performs the following functions :

1. Water balance: Kidneys play an important part in maintaining the concentration and osmotic pressure of blood by balancing the amount of water in the body. They remove excess amount of water out of the body.
2. Salt balance: They also maintain the concentration of salts in blood.
3. Acid-base balance: They maintain acid-base balance i.e., pH of the body fluid.
4. Elimination of harmful substances: Kidneys eliminate harmful substances and extra water-soluble vitamins, extra drugs, toxic chemicals and pigments out of the body. They are excreted through urine.

Question 10.
Explain function of aldosterone.
Answer:
Aldosterone hormone is secreted by the adrenal gland. It regulates quantity of Na⁺ in the body. Reabsorption is regulated by a substance renin secreted by the kidney, which converts angiotensin benzene into angiotensin. Angiotensin induces adrenal cortex to secrete aldosterone.

Question 11.
What are nephrostomes? Explain its mechanism of working.
Answer:
These are funnel shaped structures. At the broad part hairs are found. Broader part open into coelome and narrow part open into renal vein. By the movement of hairs coelomic fluid enters into the renal vein. Nephrostome is found in the embryonic stage of frog, after this stage it degenerates.

Question 12.
What do you mean by Homeostasis and Diuresis?
Answer:
Homeostasis: Keeping environment of the body permanent and regulated is called as Homeostasis. Nephrons and kidney tubules help for permanent regulation. They reabsorbs water, minerals and other nutritive substances whereas removes out excretory substances.

Diuresis: Increase in quantity of secretion of urine is called as diuresis. The substance which increases quantity of urine are called as diuretic substances. Urea is a diuretic substance which increases quantity of urine. Glucose, coffee, tea etc. are also examples of diuretic substances.

Excretory Products and their Elimination Class 11 Important Questions Long Answer Type

Question 1.
Explain the structure of kidney in brief.
Or,
Describe the structure of human kidney.
Answer:
External structure of kidney : Kidneys are bean shaped structure which lie behind the peritoneum in the lumber region, one on either side of vertebral column. It has a length of about 10 cm breadth at about 5 cm and a thickness of about 4 cm. A kidney is concave-convex in outline. The concavity lies on the inner-medium side. It possesses a longitudinal opening known as hilum.

Internal structure: L.S. of kidney showing two parts : Outer cortex and Inner medulla. The cortex is dark red while the medulla is pale in colour. Renal medulla possesses 8-18 striated conical masses called medullary pyramids. The bases of the pyramids are towards the outer side while the apices end in papillae 1-3 such papillae enter a minor calyx. The minor calyx open into major calyx which in turn produce the renal pelvis.

Urine is produced by minute thread like tubular structures named nephrons or uriniferous tubules. They constitute the structural and functional units of the kidneys. The urine formed by the nephron is poured into collecting ducts. The collecting ducts open into larger ducts of bellini. The later open at the apices or papillae of medullary pyramids.

Question 2.
Explain the structure of nephron with suitable diagrams.
Or,
Describe the structure of nephron of human with diagramshort ?
Or,
Draw well labelled diagram of human nephron.
Answer:
Nephron or renal tubules are the chief functional units of the kidney, which are made up of following two parts :
1. Bowman’s capsule: The initial part of each tubule is formed of glomerulus and a two walled cup shaped structure called Bowman’s capsule. It possesses a globular tufts of capillaries called glomerulus. Glomerulus is formed by an afferent and an efferent arteriole. Glomerulus is situated in cortex of the kidneys.

2. Secretory part: The backward portion of Bowman’s capsule is called secretory portion. It is made up of following three parts :

1. The coiled structure associated with Bowman’s capsule is called proximal convoluted tubule,
2. The mid ‘U’ shaped portion of nephron is called Henle’s loop. It is found in renal medulla,
3. The ascending limb of Henle’s loop passes into distal convoluted tubule. These tubules opens into larger ducts called collecting tubule or ducts.

For diagram:

Question 3.
What do you understand by Ammonotelism, Ureotelism and Uricotelism? Give example of each.
Answer:
Ammonotelic animals: Ammonotelic animals excreting the nitrogenous waste substances in the form of ammonia and the process of excretion is called Ammonotelism. For example Protozoans (e.g., Amoeba, Paramoecium), Sponges (Sycon), Coelenterates (e.g. Hydra), Annelids (e.g., Earthworm), Arthropods (e.g., Prawn), Molluscs (e.g., Sepia,Octopus) etc.

Ureotelic animals: Ureotelic animals excreting the nitrogenous waste products mainly in the form of urea. This process of excreting is called Ureotelism. For example Ascaris, Earthworm, Cartilagenous Fishes (Sharks), Amphibians (Frog, Toad), Aquatic reptiles (Turtles, Alligators.)

Uricotelic animals: Uricotelic animals are those which excrete thin nitrogenous waste product mainly as Uric acid. This process of excreting is called Uricotelism.
For example: Insects (Cockroach), Snake, Lizard, and birds etc.

Question 4.
Describe the process of urine formation.
Answer:
Urine is formed within kidney. Urine formation takes place in the following three stages:

1. Ultrafiltration,
2. Selective reabsorption,
3. Secretion.

Ultrafiltration: In each glomerulus, the nitrogenous excretory products such as urea etc. come with the blood through afferent arteriole and pass out through the glomerulus to efferent arteriole. The diameter of afferent arterioles is larger than that of the efferent arterioles. Because of it some amount of blood is retained in the glomerulus, therefore, some blood collects into glomerulus as a result of which a pressure is created, called as glomerular filtration pressure (GFP). It is about +75 mm Hg. The osmotic pressure of plasma protein of part of plasma is filtered out.

It is known as glomerular filtrate. It is isotonic with blood. It has most of the water, urea, amino acids, glucose, vitamin C, proteins having molecular weight less than 70,000, inorganic ions and salts etc. R.B.C. W.B.C., high molecular weight compounds and some water which is retained by the osmotic pressure of plasma proteins do not filter out.

2. Selective reabsorption: In man nearly 170 litres of glomerular filtrate is filtered out but only 1 -5 litres of urine is formed in 24 hours. The filtrate is isotonic whereas urine is hypertonic, the filtrate is slightly alkaline and the urine is acidic. It shows that some substances are reabsorbed by the renal tubules from the glomerular filtrate. This is called as selective reabsorption.

The second step in the urine formation is the selective reabsorption in which major portion of water and some physiologically important solutes like glucose, amino acids and inorganic salts like sodium chloride and sodium bicarbonates are reabsorbed back into the blood in the peritubular capillaries and vasa rectae. This reabsorption process takes place in the proximal convoluted tubule.

The tubular reabsorption may be of active reabsorption or of passive reabsorption. Glucose and amino acids which are of considerable importance to the body are actively reabsorbed. The active absorption is very rapid and continues even when the concentrations of these substances fall much below that in the blood. Rest of the useful substances like sodium, potassium, phosphates, bicarbonates etc. are passively reabsorbed by the physical process of diffusion. Water is reabsorbed by osmosis. Sodium ions are reabsorbed both by the active and the passive transport mechanism.
Vasa recta maintain a higher osmotic pressure of the extracellular fluid. In the descending limb of the loop of Henle about 5% of the glomerular filtrate is reabsorbed.

Almost the total amount of glucose, most of the amino acids, about 70 percent of potassium ions and a large amount of calcium ions are reabsorbed actively in the proximal convoluted tubule. 25 percent of potassium ions and some amounts of chloride ions and some sodium ions are reabsorbed actively by the ascending limb of the loop of Henle. The ascending limb is impermeable to water hence no water is reabsorbed into the ascending limb. This makes the filtrate dilute than plasma.

The distal convoluted tubules actively reabsorbs sodium ions and in exchange excretes some potassium ions. Some chloride ions are also reabsorbed by the DCT.

3. Secretion: The kidney tubules also excrete additional waste materials from the blood stream and put them into the filtrate. These excretory substances of blood are absorbed by the capillaries present in the wall of nephron. These absorbed excretory substances like urea, uric acid and ammonia etc. are diffused out from the capillaries of nephron and mixed with urine in nephron. This process of Bowman’s capsule is called as secretion.

Question 5.
Write short note on following :
(i) Green gland,
(ii) Nephridium.
Answer:
(i) Green glands: These are the principal excretory organs of Prawn. They are located in the second antennae. Each green gland consists of an end sac, a labyrinth and a bladder. Urine is first formed in the sac and passes through the fine tubules of labyrinth to the large sac-like bladder. A duct called ureter leads from the bladder to the base of antennae where it opens to the exterior. The end sac and the labyrinth probably excrete ammonia and uric acid respectively. The bladder also opens into thin-walled renal sac by a duct.

(ii) Nephridium: Annelids in general possess a excretory system consisting of long or short specialised tubules which are used for excretion and are called nephridia. Each nephridium consists of a ciliated funnel called nephrostome which opens into the body cavity or coelom. Nephrostome leads into a highly coiled tubule which finally opens outside the body through pores called nephridiopores present in the body wall. The nitrogenous wastes formed in the nephridia is propelled by ciliary movements and either thrown directly outside or into the alimentary canal.

Excretory Products and their Elimination Class 11 Important Questions Objective Type

1. Choose the correct answers:

Question 1.
The process of filtration takes place in :
(a) Renal capsules
(b) Henle’s loop
(c) Neck
(d) Papilla.
Answer:
(a) Renal capsules

Question 2.
The excretory organ of crustaceans is :
(a) Uriniferous tubules
(b) Green glands
(c) Cloacal glands
(d) Malpighian tubules.
Answer:
(b) Green glands

Question 3.
Contractile vacuole is responsible for :
(a) Osmoregulation and excretion
(b) Respiration
(c) Osmoregulation
(d) Excretion of excretory substances.
Answer:
(a) Osmoregulation and excretion

Question 4.
Vasopressin is associated with :
(a) Urine concentration
(b) Dilution of urine
(c) Digestion
(d) Heart beating.
Answer:
(a) Urine concentration

Question 5.
The excretory substance of human beings is :
(a) Amino acid
(b) Ammonia
(c) Urea
(d) Uric acid.
Answer:
(c) Urea

Question 6.
Concentration of urea is minimum in :
(a) Pulmonary vein
(b) Hepatic artery
(c) Portal vein
(d) Renal vein.
Answer:
(d) Renal vein.

Question 7.
Excretory products of human urine formed by protein metabolism are:
(a) Uracil, ammonia, urea
(b) Urea, uric acid, NaCl
(c) Urea, melanin, guanine
(d) Urea, uric acid, creatinine.
Answer:
(d) Urea, uric acid, creatinine.

Question 8.
Ammonia is converted into urea in :
(a) Kidneys
(b) Liver
(c) Intestine
(d) Spleen.
Answer:
(b) Liver

Question 9.
Proteolytic enzyme secreted by kidney is :
(a) Rennin
(b) Trypsin
(c) Erepsin
(d) None of these.
Answer:
(a) Rennin

Question 10.
The stage of urine formation in which blood is also excreted with urine is called:
(a) Creatinine
(b) Haematuria
(c) Anuria
(d) Ketonuria.
Answer:
(b) Haematuria

Question 11.
Aquatic snakes are generally :
(a) Aminotelic
(b) Aminophilic
(c) Ureotelic
(d) Uricotelic.
Answer:
(c) Ureotelic

Question 12.
The function of green gland is excretion. It is found in :
(a) Spider
(b) Insects
(c) Scorpion
(d) Crayfish.
Answer:
(d) Crayfish.

Question 13.
Ureotelism is found in :
(a) Mammals
(b) Aquatic insects
(c) Tadpole
(d) Birds.
Answer:
(a) Mammals

Question 14.
Excess urine formation and its removal is called :
(a) Serosis
(b) Diuresis
(c) Sclerosis
(d) Osteoporosis.
Answer:
(b) Diuresis

Question 15.
Fluid in Bowman’s, capsule is called :
(a) Water
(b) Urine
(c) Blood cells with Blood
(d) Blood plasma without Blood corpuscles.
Answer:
(d) Blood plasma without Blood corpuscles.

Question 16.
The structural and functional unit of kidney is :
(a) Neuron
(b) Nephron
(c) Respiratory cell
(d) Malpighian tubule.
Answer:
(b) Nephron

Question 17.
It is called the graveyard of R.B.Cs.:
(a) Kidney
(b) Gall bladder
(c) Spleen
(d) Liver.
Answer:
(c) Spleen

Question 18.
Haemodialysis is helpful for which diseased patient:
(a) Uremia
(b) Anaemia
(c) Diabetes
(d) Goitre.
Answer:
(a) Uremia

Question 19.
In the kidney of mammals Henle’s loop lies at the :
(a) Medulla
(b) Cortex
(c) Pelvis
(d) Ureter.
Answer:
(a) Medulla

Question 20.
Human kidney is :
(a) Pronephron
(b) Mesonephron
(c) Metanephron
(d) Opisthonephron.
Answer:
(c) Metanephron

2. Fill in the blanks:

(A)
1. The excretory orgen of prawn is …………………….. .
Answer:
Green glands,

2. Aquatic animals excrete nitrogenous excretory substances as …………………….. .
Answer:
Ammonia,

3. The substances that increases urine formation are called …………………….. .
Answer:
Diuretics,

4. The artificial removal of excretory substances from the body is called …………………….. .
Answer:
Haemodialysis,

5. …………………….. is responsible for the concentration of urea.
Answer:
Henle’s loop,

6. The yellow colour of the urine is due to the presence of …………………….. .
Answer:
Bilirubin,

7. The formation of the urea takes place in …………………….. .
Answer:
Liver,

8. The functional unit of kidneys are …………………….. .
Answer:
Nephron.

(B)
1. Ascending loop of Henle is …………………….. to water, whereas descending loop of Henle is …………………….. to it.
Answer:
Impermeable, permeable,

2. In the distal convoluated tubule of nephron of the kidney reabsorption of water occurs due to …………………….. hormone.
Answer:
Anti diuretic hormone (ADH),

3. In the glomerular filtrate in addition to …………………….. all other substances of blood plasma are found.
Answer:
Nitrogenous wastes,

4. A normal healthy adult human excrete …………………….. urea per day.
Answer:
25-30gm.

3. Match the following:

(A)

Answer:
1. (d) Cockroach
2. (e) Earthworm.
3. (a) Vasopressin
4. (c) Glomerulus
5. (b) Bird.

(B)

Answer:
1. (d) Bile juice
2.  (a) Urecotelic
3. (e) Urea.
4. (b) Green gland
5. (c) Kidney.

(C)

Answer:
1. (c) Bony fishes
2. (e) Nephron.
3. (d) Urinary bladder
4, (a) Bird,
5. (b) Reabsorption of water.

4. Answer in one word :

1. Name the pigment found in urine.
Answer:
Urochrome,

2. Name the substance which regulates the excretion of sodium and potassium in urine and place where it is formed.
Answer:
Aldosterone, Adrenal cortex,

3. Name the factor which regulates the volume of urine.
Answer:
Vasopressin hormone,

4. Name the excretory organ of Hydra.
Answer:
Plasma membrane,

5. Name the hormone which regulates the secretion of urine in nephron.
Answer:
Vasopressin,

6. Name the excretory substance of Man.
Answer:
Urea, CO₂,

7. What is loop of Henle?
Answer:
U shape tube of nephron,

8. Name the artery which carries blood towards the kidney.
Answer:
Renal artery,

9. Where is urea formed?
Answer:
Liver.

5. Write true or false:

1. Micturition occurs by reflex action.
Answer:
True,

2. ADH helps for excretion of urine by making it hypotonic.
Answer:
False,

3. Henle’s loop plays important role in making urine concentrated.
Answer:
True,

4. In the Bowman’s capsule protein less liquid is filtered out from the blood plasma.
Answer:
False,

5. In the proximal convoluted tubule (PCT) active reabsorption of glucose occurs.
Answer:
True.

Students get through the MP Board Class 11th Biology Important Questions Chapter 4 Animal Kingdom which are most likely to be asked in the exam.

MP Board Class 11th Biology Important Questions Chapter 4 Animal Kingdom

Animal Kingdom Class 11 Important Questions Very Short Answer Type

Question 1.
Write down three main characters due to which birds are able to fly.
Answer:
Three main characters due to which birds can fly are :

1. Body is streamlined and is covered with feathers.
2. Forelimbs are modified as wings for flying.
3. Bones are pneumatic (Porous), this reduces the weight of the body.

Question 2.
Differentiate radial and bilateral symmetry. (Any two)
Answer:
Differences between Radial and Bilateral Symmetry

Question 3.
Write three characteristics of protochordata.
Answer:

1. They possesses notochord either throughout the whole life or in some phase of life.
2. Vertebral column does not develop.
3. They do not have a cranium and the jaws.

Question 4.
Give examples of three stationary organisms.
Answer:

1. Leucosolenia,
2. Sycon,
3. Grantia.
   All these organisms belong to phylum Porifera and are found attached to the stone or substratum.

Question 5.
Write two characters of sub-phylum :
(a) Urochordata,
(b) Cephalochordata,
(c) Hemichordata.
Answer:
(a) Urochordata :

• They are marine.
• They are sessile forms and possess the notochord in the tail region in the larval stage which is degenerated completely in the adult stage.
• Adults are always enclosed in a tunic composed of animal cellulose, e.g., Herdmania known as sea squirt, etc.

(b) Cephalochordata :

• Animals of this sub-phylum are exclusively marine and solitary animal.
• They are small, fishlike animals.
• Notochord is present from head to tail.
• Many gonads are present, e.g., Amphioxsus, Asymmetron, etc.

(c) Hemichordata :

• Its body is divided into Probosis, Colar and Neck.
• In Probosis, notochord like structure is formed.
• They are marine animals, e.g., Balanoglossus.

Question 6.
What are glass sponges?
Answer:
Skeleton of some sponges are transparent and their spicules or spines are silicious thus they are called as glass sponges.

Animal Kingdom Class 11 Important Questions Short Answer Type

Question 1.
Differentiate between Intracellular digestion and Extracellular digestion. (NCERT)
Answer:
Intracellular digestion :
The process of digestion which occurs inside the cell is called as intracellular digestion. Unicellular organisms like Amoeba, Paramoecium engulf food by endocytosis process then hydrolytic enzymes present in the lysosomes help for digestion. After absorption of digested food, undigested food is released out of the body by exocytosis process. Whereas Extracellular digestion is the process of digestion which occurs outside the cell. In multicellular organisms extracellular digestion occurs in the digestive system.

Question 2.
Write differences between Direct and Indirect development.
Answer:

• Direct development: In this type of development larva stage is not found. Zygote directly develops to form individual, e.g., Human, Rat, Elephant, Monkey etc.
• Indirect development: In this type of development zygote first develops into larva, then larva develops to form young individual, e.g., Cockroach, frog etc.

Question 3.
What is the importance of presence of air bladder in fishes?
Answer:
Air bladder present in the fishes help for buoyancy, due to which they may swim easily, even if it reaches to the bottom it can come up easily, e.g., Exocoetus, Rohu fishes.

Question 4.
Write differences between Chordates and Non-chordates.
Answer:
Differences between Chordates and Non-chordates

Question 5.
Explain adaptations in birds for aerial habitat.
Answer:
Basic features of birds with reference to habitat:
Birds are terrestrial organ-isms which can fly in the air. Following adaptations are found in them for aerial habitat:

• Body is covered with feathers which hold air and decreases body weight.
• Forelimbs are modified into wings.
• Digits of hind limbs are adapted for sitting on the branches of the tree.
• Bones are hollow and aerated thus decreases body weight for flying.
• Urinary bladder is not found and they do not store waste product in the body (As it is produced is released out from the body).
• Foot webs are found in aquatic birds for swimming.
• Air sacs are found on the lungs.
• Beak is adapted according to its food habit. It is toothless.

Question 6.
Write down the name of the animals which are related with the given organs :
1. Compound eye,
2. Carapace,
3. Medusa,
4. Flame cells,
5. Placoid scales,
6. Blabber,
7. Parapodia.
Answer:
Organs – Animals related to it

1. Compound eye – Periplanata
2. Carapace – Crab
3. Medusa – Aurelia
4. Flame cells – Plan aria
5. Placoid cells – Scoliodon
6. Blabber – Whale fish
7. Parapodia – Nereis
8. Tube feet – Starfish

Question 7.
Write down the difference between :
1. Coelomate and Pseudocoelomate,
2. Urochordata and Cephalochordata,
3. Flat worm and Round worm,
4. Bony fishes and Cartilage fishes, 5. Oviparous and Viviparous, 6. Diploblastic and Triploblastic.
Answer:
1. Coelomate and Pseudocoelomate:
Presence of true coelom with mesoderm surrounding the body cavity entirely is called Coelomate, whereas Pseudocoelomate are partially open fluid filled body cavity which develops in the blastocoel, so mesoderm does not entirely surround the body cavity.

2. Urochordata and Cephalochordata :
Urochordata are marine sessile animals possessing notochord in tail region in larval stage and degenerates in adult stage whereas Cephalochordata are marine and solitary animal possessing notochord from head to tail.

3. Flat Worm and Round Worm:
The animal body of Platyhelminthes are flat and tapering only at the anterior end are called Flat worm. Whereas the animal body of Nemathelminthes are round in shape, tapering at both ends.

4. Bony fishes and Cartilage fishes :
Fishes having bones are called Bony fishes and they are fresh water as well as marine whereas Cartilaginous fishes are having cartilage they are all marine.

5. Oviparous and Viviparous :
Oviparous animals lay eggs outside the body and fertilization may be internal or external, whereas Viviparous animals hatch eggs within the female body and fertilization is internal.

6. Diploblastic and Triploblastic :
Diploblastic animals are those where their embryo are made up of two germ layers : Ectoderm and endoderm, whereas Triploblastic animals are those where their embryo are made up of three germ layers : Ectoderm, meso-derm and endoderm.

Question 8.
What is False fish? Explain it with examples.
Answer:
Those animals which live in water and have the capacity to swim in water like fishes. But they do not come under class Pisces. So they are called false fish.
Example :

• Jelly fish : It is Aurelia genus and is in phylum Coelenterats.
• Silverfish : It is in phylum Arthropoda and is genus of Lepisma.
• Devilfish : It is in phylum Mollusca of genus Octopus.
• Starfish : It is in phylum Echinodermata of genus Asterias.

Question 9.
Describe the characteristic features of the class mammalia.
Or
In which class of Animalia human is included and why? Explain with five features of this class.
Answer:
Characteristics of class mammalia : It is the highly developed group of king-dom animalia.
Human is placed under the class mammalia, because of the following reason :

• They are isothermal. Body is covered by hairs. Skin contains sweat and oil glands.
• Females possess mammary glands, which secrete milk after the birth of young ones and thus, infant is given nutrition in the initial stage of growth.
• The heart is four chambered with two auricles and two ventricles. Only the left aortic arch is present.
• Ear with fleshy external ear or pinna.
• A muscular diaphragm is present, which separates the thoracic cavity from the abdominal cavity.
• They have well developed brain, this enables them to learn.
• Number of neck vertebrae is always seven.
• They are warm blooded animals.

Question 10.
What do you mean by Amphibian? Give eight characteristics of class Amphibia.
Answer:
Those animals of phylum Chordata which live both on land and in water are called Amphibian animals e.g., Frog (Rana tigrind), Bufo etc.
Characteristics of class Amphibia :

• Their body is fit for survival in water and on land.
• They are cold blooded animals.
• Their skin is moist, slippery and glandular, due to which they can respire both on land and in water.
• They possess ears which consists of tympanum.
• R.B.Cs. are nucleated.
• Heart is three chambered.
• Webs are present between the digits of hind limb.
• External fertilization occurs in water.

Question 11.
What do you understand by symmetry of animals? How many kinds of symmetry is found in animals ? Write at least any one character and give one example from each type of symmetry.
Answer:
Symmetry :
The arrangement of various parts of the body of organisms is called as symmetry .There are three types of symmetry found in animals :

1. Asymmetry :
   In asymmetrical arrangement body of animals cannot be divided into two equal parts in any plane, e.g., Gastropods, Sponges.
2. Radial symmetry :
   In this type, body of animals can be divided into two equal halves by cutting in any of the radial planes, e.g., Hydra and Starfish.
3. Bilateral symmetry :
   In this type, body of animals can be divided into two equal halves through only one plane i.e., main axis of the body passing through the center, e.g., All vertebrate animals.

Question 12.
Write the characters of the phylum Annelida.
Answer:
Characteristic features of the phylum Annelida :

• They are mostly aquatic, marine or fresh water, burrowing or living in tubes.
• The body is thin, elongated, cylindrical and is metamerically segmented, externally by transverse groove and internally by septa into a number of divisions, each division is called segment or metamere.
• Body is bilaterally symmetrical, triploblastic and coelomatic, which is covered by a contractile and muscular body wall. Epidermis is cuticulized.
• A straight, tube like alimentary canal is found in the center of body cavity which is extending from mouth to anus.
• Locomotion takes place by setae or chaetae.
• Blood vascular system is closed type. Blood is red due to presence of haemoglobin. R.B.Cs. are not found in the blood.

Question 13.
Describe the characteristic features of the kingdom Animalia.
Answer:
Characteristic features of the kingdom Animalia :

• The organisms of this kingdom are eukaryotic, multicellular, heterotrophic and holozoic in nutrition.
• Cell wall and plastids are absent.
• Locomotion and movement occur.
• All of them are consumers.
• They reproduce sexually, except some lower animals.
• They possess muscles, which possess the capacity of expansion and contraction.
• Body is triploblastic, bilaterally symmetrical and possesses the capacity of sensation.
• They possess nervous and hormonal systems for coordination.

Question 14.
Describe the important adaptations of the Arthropods.
Answer:
Phylum Arthropoda is the largest phylum of the animal kingdom. The following adaptive characters are found in the arthropods :

• Body is covered with a chitinous cuticle forming exoskeleton.
• The salts of CaC03 and calcium phosphates are also present in the exoskeleton, which increase the hardness of the body.
• Respiration through general body surface by gills in aquatic forms, trachea or booklungs in terrestrial forms.
• Moulting is present in the exoskeleton.
• The body is bilaterally symmetrical and metamerically segmented.
• Exoskeleton is solid, hence it provides the space for joining the muscles.
• The animals are suited for aquatic as well as terrestrial environment.
  Ex. Butterfly, Scorpion, Cockroach, Housefly, Mosquito.

Question 15.
Describe the characteristic features of the phylum Chordata.
Or
(A) Write three important characters of phylum Chordata.
(B) Write the name of phylum of the following animal:
(i) Star fish,
(ii) Jelly fish,
(iii) Octopus,
(iv) Earthworm,
(v) Tape worm,
(vi) Paiaemon.
Answer:
Characteristic features of the phylum Chordata :

• Notochord is present in any stage of life.
• Nervechord is present.
• Gills are present in any stage of life.
• A heart made up of muscles is present.
• Presence of closed circulatory system and blood cells contain R.B.Cs.
• Endoskeleton is present, which is made up of bones and cartilages.
• Presence of two pairs of appendages and well developed system. e.g., Man, Frog, Lizards, etc.

(B)
Name of related animal and their phylum :
Animal – Phylum

• Starfish- Echinodermata
• Jellyfish – Coelenterata
• Octopus – Mollusca
• Earthworm – Annelida
• Tapeworm – Platyhelminthes
• Paiaemon – Arthropoda.

Question 16.
Give characteristic features of phylum Moliusca.
Answer:
Characteristic features of Moliusca :

• They are essentially aquatic, mostly marine, few fresh water and some terrestrial forms.
• The body is soft, bilaterally symmetrical and consists of head, foot, circular mantle and visceral mass.
• Body is protected by an exoskeletal of calcareous shell, secreted by mantle.
• They possess a mantle cavity between body wall and mantle, in which digestive system, reproductive system and kidneys are opened.
• Head is distinct, bearing the mouth and provided with eyes, tentacles and other sense o-gans.
• Ventral body is modified into muscular flat or foot, which is variously modified for creeping, burrowing and swimming.
• Pharynx contains a rasping organ the radula except in bivalvia (pelecypoda).

Question 17.
Name the class which is represented by bats. Give three reasons.
Answer:
Bats are placed under the class Mammalia due to the following features :

• It has mammary glands with teats,
• Body is covered by hairs and skin possessing sweat and oil glands,
• Females give birth to young ones,
• It has four chambered heart.

Question 18.
Why whale fish is placed under the class mammalia? Give four reasons.
Or
Why is whale included in Mammalia? Explain with five reasons.
Answer:
Whale is placed under the class Mammalia, because of the following reasons :

• Females give birth to young ones.
• It contains mammary glands with teats.
• Their heart is four chambered.
• Fertilization is internal.
• Young ones develop within uterus.

Question 19.
Why frogs are placed under the class Amphibia? Give four reasons.
Answer:
Frogs are placed under the class Amphibia, because of the following reasons :

• Their body is fit for survival in water and on land,
• They are cold blooded animals,
• Their skin is moist, slippery and glandular, due to which they can respire both on land and in water,
• They possess ears.

Question 20.
Give at least one example of the following animals :
1. Egg laying mammal,
2. Flying mammal,
3. Flying reptile,
4. Flying fish.
Answer:
Animal – Example

1. Egg laying mammal – Echidna
2. Flying mammal – Bat
3. Flying reptile – Draco
4. Flyingfish – Exocetus.

Question 21.
What do you understand by Bilateral Symmetry? Explain it with example.
Answer:
Bilateral symmetry : If the body can be divided into two equal halves by one plane only it is called bilateral symmetry. Here the body organs are paired and occur on the two sides of a central axis, e.g., all vertebrates like fishes, human beings, birds, etc.

Such animals possess a front or anterior end and a rear or posterior end. They also possess an upper back or dorsal side and a lower belly or ventral side. On the basis of dorsal and ventral sides the right and left side® ‘if the body are called lateral sides. Man, Snake, Earthworm are the examples of Bilateral symmetry.

Question 22.
Differentiate between Starfish and Flyingfish on the basis of their body
symmetry and exoskeleton.
Answer:
Differences between Starfish and Flyingfish

Question 23.
Write down the name of phylum and class of the following animals :
1. Roundworm,
2. Leech,
3. Scorpion,
4. Bat.
Answer:

1. Roundworm:Phylum – Aschelminthes
   Class – Nematoda
2. Leech :Phylum – Annelida
   Class – Hirudinia
3. Scorpion:Phylum – Arthropoda
   Class – Arachnida
4. Bat:Phylum – Chordata
   Class – Mammalia.

Question 24.
Write down the name of phylum and class of the following animals :
1. Tapeworm,
2. Nereis,
3. Cockroach,
4. Starfish.
Answer:

1. Tapeworm:Phylum – Platyhelminthes
   Class – Cestoda
2. Nereis:Phylum – Annelida
   Class – Polychaeta
3. Cockroach :Phylum – Arthropoda
   Class – Insecta
4. Starfish: Phylum – Echinodermata
   Class – Asteroidia.

Question 25.
Write down the name of phylum and class of the following animals :
1. Hydra,
2. Earthworm,
3. Unio,
4. Horsefish,
5. Turtle.
Answer:

1. Hydra :Phylum – Coelenterata
   Class – Hydrozoa
2. Earthworm:Phylum – Annelida
   Class – Oligochaeta
3. Unio: Phylum – Mollusca
   Class – Gastropoda
4. Horse fish :Phylum – Chordata
   Class – Osteichthyes
5. Turtle:Phylum – Chordata
   Class – Amphibia.

Question 26.
Draw a well labelled diagram of Earthworm.
Answer:

Fig. Earthworm (Pheretima) : (A) Ventral view; (B) Segment 1, 2 and 3; (C) Reproductive organs

Question 27.
Write down the zoological name of the following animals :
1. Housefly,
2. Elephant,
3. Ostrich,
4. Roundworm,
5. Kangaroo.
Answer:
Common Name – Zoological Name

1. Housefly – Musca domestica
2. Elephant – Elephas maximus
3. Ostrich – Struthio
4. Roundworm – Ascaris lumbricoidis
5. Kangaroo – Macropus.

Question 28.
Pila and Octopus are kept in same phylum why?
Answer:
Pila and Octopus are kept in same phylum because :

• Their body is soft covered by shell.
• Body consists of head, visceral mass and foot.
• Whole body is covered by muscular mantle.

Question 29.
Write the name of locomotory organs of the following animals :
1. Amoeba,
2. Earthworm,
3. Paramoecium,
4. Snake,
5. Starfish,
6. Hydra,
7. Euglena.
Answer:
Animal – Name of the locomotory organs

1. Amoeba – Pseudopodia.
2. Earthworm – Setae.
3. Paramoecium – Cilia.
4. Snake – Ribs and scales.
5. Starfish – Arms.
6. Hydra – Tentacles.
7. Eugiena – Flagella.

Question 30.
Write the phylum of following animals :
1. Starfish,
2. Jellyfish,
3. Dogfish,
4. Horsefish,
5. Devilfish,
6. Whalefish,
7. Silverfish.
Answer:
Animal – Phylum

1. Starfish – Echinodermata
2. Jellyfish – Coelenterata
3. Dogfish – Chordata
4. Horsefish – Chordata
5. Devilfish – Mollusca
6. Whalefish – Chordata –
7. Silverfish – Arthropoda.

Question 31.
Give one example of each of the following :
1. Animal with largest life span,
2. Largest lizard,
3. Largest snake,
4. Largest animal of the world.
Answer:
Animal – Examples

1. Animal with largest life span – Turtles
2. Largest lizard – Kamado dragon
3. Largest snake – Python
4. Largest animal of the world – Blue whale.

Question 32.
All vertebrates are chordates, but all chordates are not vertebrates. Explain.
Answer:
All vertebrates have three important characteristics :

• Presence of Notochord,
• Presence of nerve chord and
• Presence of gill slits.

All vertebrates are bilaterally symmetrical, Notochord is replaced by vertebral column, Heart is ventrally situated, Level of organisation is observed, closed circulatory system is found in them, tail is found in them. On the basis of all above characteristics it is clear that all vertebrates are chordates, whereas all chordates are not vertebrates because in vertebrates notochord is found in embryonic stage whereas in adult stage it is replaced by vertebral column and chordate may or may not has cranium jaws, vertebral column and brain.

Thus, it is clear that all vertebrates are chordates but all chordates are not vertebrates.

Question 33.
Write the scientific name of the following animal:
1. Frog,
2. Man,
3. Cat,
4. Ox.
Answer:
Common Name – Zoological name

1. Frog – Ran a tigrina
2. Man – Homo sapiens
3. Cat – Felis domestica
4. Ox – Bos indicus.

Question 34.
Classify the classes of Phylum chordata.
Answer:
Phylum chordata is classified into seven classes :
Class – Example

1. Cyclostomata – Petromycin
2. Chondricthyes – Scoliodon
3. Osteichthyes – Labeo
4. Amphibia – Rana
5. Reptilia – Snakes
6. Aves – Columbia
7. Mammals – Macropus (Kangaroo)

Question 35.
Write five phylum giving examples.
Answer:
Five Phylum are :
Phylum – Example

1. Porifera – Sycon
2. Coelenterata – Hydra
3. Platyhelminthes – Planaria
4. Nemathelminthes – Ascaris
5. Annelida – Pheritima.

Question 36.
Write short notes on :
1. Haemocoel,
2. Porifera,
3. Insecta,
4. Cyclostomata,
5. Protochordata,
6. Nematoda,
7. Metamerism.
Answer:
1. Haemocoel: Coelom is a cavity which lies between body wall and digestive tract. It is filled with a fluid called coelomic fluid, but in phylum Arthropoda, in place of coelomic fluid, blood is filled, therefore it is called Haemocoel. It works as transporter.

2. Porifera :
General characteristics of phylum Porifera :

• They are radially symmetrical, multicellular and diploblastic animals.
• They are mainly marine except few sedentary and colonial or solitary.
• The skeleton is formed of calcareous or siliceous spicules present in between gelatinous substance.
• Body is perforated by numerous pores called Ostia.
• Nervous system is absent. Digestion is intracellular. No respiratory and excretory organs are present, e.g., Sycon, Spongilla.

3. Insecta :
It is the class of Phylum Arthropoda, which has following points :

• Body is divisible into head, thorax and abdomen.
• Thorax is three segmented and carries three pairs of legs and two pairs of wings.
• Mostly terrestrial but some are aquatic.

4. Cyclostomata :
It is a part of Phylum chordata, which have following characters :

• It consists of Cranium box, Jaws are absent, but mouth is suctorial.
• Body is long, narrow, cylindrical with laterally compressed tail. ‘
• It appears like fish, but skin is naked glandular.
• Single nostril is found on the dorsal surface of the head, e.g., Petromyzon.

5. Protochordata :
It is a part of chordata, having following characters :

• Notochord is not properly developed.
• Cranium and Jaws are absent.
• Body is laterally compressed and leaf like.

6. Nematoda:

• Nematodes have tube within a tube body plan with mouth, pharynx, intestine and anus. Body is covered with thick cuticle.
• They have unsegmented triploblastic and bilaterally symmetrical cylindrical body.
• Posterior end of body is frequently curved in males while pointed in females. Males are always smaller than females.
• Body is not distinguished into different regions. Head is not distinct.
• They are pseudocoelomic.

7. Metamerism :
The body of many animals is formed of numerous segments which show serial repetition of parts. This kind of segmentation is called metameric segmentation and the phenomenon is known as metamerism.

Question 37.
Give eight characteristics of super class Pisces.
Answer:
Characteristics of super class Pisces :

1. They are aquatic vertebrates,
2. Body is covered by scales,
3. They are cold-blooded organisms (Poikilothermal),
4. Heart is two chambered,
5. Respiration by gills,
6. Tympanic membrane absent,
7. Lateral line is found on the body,
8. Fins present for swimming.

Question 38.
Compare the oviparous, viviparous and ovo-viviparous among animals.
Answer:
Comparison of Oviparous, Viviparous and Ovo-viviparous Animals

Question 39.
“Number of offsprings produced by oviparous and viviparous organisms is equal”. Yes or No? Give reason.(NCERT)
Answer:
Oviparous organisms lay eggs whereas Viviparous organisms gives birth to young one.
Number of offsprings produced by them are not equal because in oviparous organisms internal or external fertilization occurs. They lays large number of eggs which undergoes various stages of development. During this long period of development some eggs get spoiled and remaining hatches to produce offsprings, whereas viviparous organisms give birth to young individual which are very less in number. Development of embryo occurs directly in the uterus of mother and no larva stage appears.

Question 40.
If a specimen is provided to you, what step will you take to classify the organisms? (NCERT)
Answer:
Inspite of different external features and shapes, some basic similarities are found in cellular organization, body symmetry, type of coelome, digestive system, circulatory system and reproductive system of the organisms.
To classify, all these features can be considered.

Question 41.
How structure of coelome and coelomate is helpful in the classification of living organisms? (NCERT)
Answer:
Coelome is defined as a cavity lined by mesoderm, it lies between the body wall and the digestive tract in which various internal organs are found suspended. Presence or absence and nature of coelome is the main basis of classification. Organism with coelome is called as Coelomate. e.g., Annelids, Echinodermates and Chordates etc.

The animals without coelome are called as Acoelomate. eg., Sponges, coelentrates and flatworms. In some other organisms mesoderm is found in the form of small packs scattered in between outer ectoderm and inner endoderm. Such organisms are called are Pseudocoelomate. eg., Roundworms such as Ascaris.

Animal Kingdom Class 11 Important Questions Long Answer Type

Question 1.
Give the general characteristic of phylum Porifera.
Answer:
General characteristics of phylum Porifera :

• They are radially symmetrical, multicellular and diploblastic animals.
• They are mainly marine except few sedentary and colonial or solitary.
• The skeleton is formed of calcareous or siliceous spicules present in between gelatinous substance.
• Body is perforated by numerous pores called Ostia.
• Nervous system is absent. Digestion is intracellular. No respiratory and excretory organs are present, e.g., Sycon, Spongilla.

Question 2.
Give eight characteristics of phylum Coelenterata.
Answer:
Characteristics of phylum Coelenterata :

• They are multicellular animals showing cell-tissue level of body organisation with most of the cells specialised for different functions and some forming a tissue. They exhibit physiological division of labour.
• Cnidarians are diploblastic metazoans, the body wall is made up of two layers the outer ectoderm and inner endoderm (gastroderm) with middle non-living gelatinous layer mesoglea.
• Coelenterates exhibit a blind sac plan and are radially symmetrical.
• Cnidarians are acoelomate.
• Head and segmentation absent.
• These are short or slender, extensile projections called tentacles, encircle the mouth in one or more whorls and are used for food-capture, intake and defence.
• Coelome is not found in them. Only one cavity found in the body called coelenteron, which is enclosed by endoderm. e.g., Hydra, Aurelia.

Question 3.
“Arthropoda is regarded as largest group of animals.” Give reason.
Answer:
Arthropoda is regarded as a most successful and largest group of animals. It has about 9,00,000 species out of which 7,50,000 species are the members of class Insecta. Due to following adaptations they forms approximately two third (2/3) part of the total number of animals present in the world :

1. Legs are divided into small segments.
2. They are found in different habitats likes air, water, soil as parasites etc.
3. Body is triploblastic, bilaterally symmetrical.
4. The true coelome is greatly reduced.
5. Open circulatory system is found in them.
6. Excretory organs are malpighian tubules.
7. Compound eyes are found in them.
8. Respiration occurs through tracheal system.
9. The segments of the body bears paired, jointed and lateral appendages which are modified as jaws, gills and legs.
10. Body is covered by thick exoskeleton containing Chitin. e.g., Palaemon, cockroach, Julus, Crab etc.

Question 4.
Write down the characteristics of phylum Platyhelminthes.
Answer:
General characters of Platyhelminthes :

• Flatworms are triploblastic (i.e., consists of three germinal layers ectoderm, mesoderm and endoderm). Acoelomate, bilaterally symmetrical, dorsoventrally flattened organisms with anteriorly differentiated into a definite head.
• They have flattened body because of their primitive system of circulation and excretion. Each cell of the body must be near to the body surface to get nutrients and oxygen and for the removal of waste products and carbon dioxide.
• Platyhelminthes have unsegmented body except in tapeworms (Class-Cestoda). In Cestodes body is strobilated, i.e., it consists of large number of proglottids.
• Flatworms are with blind sac body plan.
• The alimentary canal is either absent or highly branched and only mouth is present and anus is absent.
• They do not have any body cavity or coelom, various organs are embedded in a sort of solid packing tissue known as mesenchyme or parenchyma.

Question 5.
Explain modern classification of Animal Kingdom giving two-two examples.
Answer:
Modem classification of Animal Kingdom, showing important phylum is as follows, Animal Kingdom is divided into three branches. They are :
(A) Mesozoa Branch :
They are tissueless group of cells. It consists of only one
phylum.
1. Phylum Mesozoa :

• Body is made up of group of cells.
• Found in water, e.g., Diacima.

(B) Parazoa Branch :
It has cellular organization, clear mouth, anus absent. It has only one phylum.
2. Phylum Parazoa :

• Body consists of numerous pores.
• It is found in stagnant and flowing water, e.g., Sycon, Euspongia.

(C) Eumetazoa Branch :
It consists of tissue, organ, mouth alimentary canal. It consists of following
phylum :
3. Phylum Coelenterata:

• Coelenteron present, radial symmetry and tissue present,
• It is a multicellular organism, e.g., Hydra, Aurelia.

4. Phylum Platyhelminthes :

• Body ribbon shaped,
• Body cavity absent, e.g., Taenia solium, Planaria.

5. Phylum Nematoda :

• Body is long and round,
• Female is longer than male. e.g., Ascaris.

6. Phylum Annelida :

• Body is segmented,
• Locomotion by setae. e.g., Leech, Earthworm.

7. Phylum Mollusca :

• Body is soft,
• Shell is present all round the body, e.g., Unio, Pila.

8. Phylum Arthropoda :

• Jointed legs,
• Exoskeleton made of Chitin,
• Eyes simple or compound, e.g., Cockroach, Scorpion.

9. Phylum Echinodermata :

• Body radially symmetrical,
• Skin covered with spines, e.g., Starfish.

10. Phylum Chordata:

• Animal having notochord, nervecord and gills are present.
• All organs are well developed, e.g., Frog, Man, Fish.

Question 6.
Write down the characteristics of Chordata; classify it giving two-two characters with examples.
Answer:
Characteristics of Chordata :
Characteristic features of the phylum Chordata :

• Notochord is present in any stage of life.
• Nervechord is present.
• Gills are present in any stage of life.
• A heart made up of muscles is present.
• Presence of closed circulatory system and blood cells contain R.B.Cs.
• Endoskeleton is present, which is made up of bones and cartilages.
• Presence of two pairs of appendages and well developed system. e.g., Man, Frog, Lizards, etc.

Phylum Chordata is further classified into 7 classes; they are :
1. Class Cyclostomata :

• Cranium box is present,
• Lower jaw absent,
• Suctorial mouth, e.g., Petromyzon, Myxine.

2. Class Chondrichthyes :

• Endoskeleton is cartilagenous,
• Operculum and air bladder are absent, e.g., Scoliodon, Torpedo.

3. Class Osteichthyes :

• Endoskeleton formed of bones,
• Gills are covered by operculum, e.g., Labeo, Hippocampus.

4. Class Amphibia :

• They are amphibian animals, living both on land and in water but its larva grows in water only,
• It consists of four limbs, e.g., Rana tigrina, Bufo.

5. Class Reptiles :

• They creep on land,
• Skin is dry. e.g., Calotis, Naja.

6. Class Aves :

• Forelimbs modified into wings, and whole body is covered by feathers,
• Air is filled in bones, e.g., Columba, Passer.

7. Class Mammals :

• Presence of hair on the body,
• Mammary glands with teats, e g., Macropus, Homo sapiens.

Question 7.
If there is lack of knowledge of basic features then will you face problem to classify animals? (NCERT)
Answer:
Following problems may be faced while classifying the animals :

• Different levels of organisations are found in different organisms, such as cellular level, tissue level, organ level etc.
• Some animals are radially symmetrical and some are bilaterally symmetrical.
• Some animals has closed circulatory system and some has open circulatory system.
• Some shows extracellular and some shows intracellular digestion.
• Some are acoelomate, some are coelomate and some are pseudocoelomate.
  Thus, lack of all above basic knowledge causes problems to classify animals.

Question 8.
Classify Mammalia into subclasses with characters and examples.
Answer:
There are three subclasses : Prototheria, Metatheria and Eutheria.
(A) Prototheria :

• Nippleless mammary glands.
• External ear absent.
• Egg laying mammals.
  Examples : Platypus, Ornithorincus.

(B) Metatheria :

• Mammary glands with nipples.
• External ear present.
  Examples: Kangaroo.

(C) Eutheria :

• These are true mammals with allantoic placenta.
• They give birth to fully developed young ones.
• Mammary glands and their teats are well-developed.
• Embryo develops inside the uterus and is nourished by a true allantoic placenta.
  Examples: Talpa, monkey, man, whale, dog, goat, rat, bat, elephant (Elephas), tigers, cows, horse, squirrel, etc.

Question 9.
Write short note on following :
(1) Class-Aves,
(2) Class-Reptilia,
(3) Class-Pisces.
Answer:
(1) Class-Aves:
It is an important class of phylum-Chordata. It includes organisms which can fly and has notochord, nerve cord and gill slits in some stages of its life cycle.
Characteristic features :

• They are warm blooded organisms,
• Body is covered with feathers,
• Body is divided into head, neck, trunk and tail,
• Air sacs are found on the lungs,
• Bones are hollow,
• Heart is four chambered,
• Forelimbs are modified into wings.
  Examples : Columba, Peacock, Ostrich etc.

(2) Class-Reptilia :
Class-Reptilia belongs to phylum-Chordata.
Characteristic features :

• They are cold blooded animals,
• Skin is dry and consists of scales,
• RBCs are nucleated,
• Mostly terrestrial but some are aquatic,
• Heart consists of three chambers,
• They show internal fertilization,
• Body is divided into head, trunk and tail,
• They are oviparous, a few snakes are viviparous.
  Examples : Lizard, Snake, Crocodile etc.

(3) Class-Pisces :
Class-Pisces is an important class of phylum-Chordata. It includes aquatic organisms.
Characteristic features :

• Body is streamlined,
• Body is covered by scales,
• They are cold blooded organisms,
• Heart is two chambered,
• Respiration by gills,
• Lateral line is found on the body,
• Fins help in swimming,
• Tympanic membrane is absent.
  Example : Scoliodon, Rohu fish, Torpedo etc.

Animal Kingdom Class 11 Important Questions Objective Type

1. Choose the correct answers:

Question 1.
Water vascular system is the characteristics feature of:
(a) Porifera
(b) Cnideria
(c) Echinodermata
(d) Chordata.
Answer:
(c) Echinodermata

Question 2.
All members of ………………. are marine :
(a) Porifera
(b) Coelenterata
(c) Echinodermata
(d) Anthozoa.
Answer:
(c) Echinodermata

Question 3.
Following is the important feature of arthropoda :
(a) Jointed legs
(b) Three pairs of legs
(c) Sheath on body
(d) Two pairs of wings.
Answer:
(a) Jointed legs

Question 4.
Which of the following is a true fish :
(a) Cuttlefish
(b) Silverfish
(c) Whale
(d) Flyingfish.
Answer:
(d) Flyingfish.

Question 5.
Amnion is found in the embryo of:
(a) Cockroach
(b) Tadpole
(c) Fish
(d) Lizard.
Answer:
(d) Lizard.

Question 6.
Animals found in the bottom of sea are called as :
(a) Lentic
(b) Lotic
(c) Benthic
(d) Pelagic.
Answer:
(c) Benthic

Question 7.
Pearl formed from Pearl oyster is :
(a) First drop of rain
(b) Drop of dew
(c) Egg which cannot come outside the body
(d) A round external cup buried in the skin.
Answer:
(d) A round external cup buried in the skin.

Question 8.
Phylum which contains largest number of species :
(a) Chordata
(b) Arthropoda
(c) Insecta
(d) Mollusca.
Answer:
(b) Arthropoda

Question 9.
Which of the following animal possessing exo and endoskeleton :
(a) Frog
(b) Earthworm
(c) Snake
(d) Leech.
Answer:
(c) Snake

Question 10.
Which of the following is not a fish :
(a) Liingfish
(b) Dogfish
(c) Catfish
(d) Silverfish.
Answer:
(d) Silverfish.

Question 11.
Locomotory organ of Amoeba is:
(a) Tentacle
(b) Pseudopodia
(c) Flagella
(d) Cilia.
Answer:
(b) Pseudopodia

Question 12.
Kangaroo is :
(a) Prototheria
(b) Metatheria
(c) Eutheria
(d) Reptiles.
Answer:
(b) Metatheria

Question 13.
Animals of …………… class has three pairs of legs :
(a) Arthropoda
(b) Gastropoda
(c) Insecta
(d) Crustacea.
Answer:
(c) Insecta

Question 14.
Mesoglea is the characteristic feature of the phylum :
(a) Porifera
(b) Coelenterata
(c) Annelida
(d) Hydrozoa.
Answer:
(b) Coelenterata

Question 15.
Leech is:
(a) Parasitic
(b) Autotrophic
(c) Roundworm
(d) Flatworm.
Answer:
(a) Parasitic

Question 16.
Which of the following is an oviparous mammal:
(a) Whale
(b) Platypus
(e) Rabbit
(d) Snake.
Answer:
(b) Platypus

Question 17.
Best definition of birds:
(a) They are flying
(b) Isothermic
(e) Winged bipedal
(d) Above tetrapod.
Answer:
(d) Above tetrapod.

Question 18.
Which of the following is a flying fox:
(a) Fox
(b) Bat
(e) Reptile
(d) Mollusca.
Answer:
(b) Bat

Question 19.
Causal organism of filaria disease is:
(a) Fasciola
(b) Taenia
(c) Wuchereria
(d) Mosquìto.
Answer:
(c) Wuchereria

Question 20.
Light blue colour of the blood of arthropods is due to:
(a) Haemoglobin
(b) Haemocyanin
(c) Hirudin
(d) None of these.
Answer:
(b) Haemocyanin

Question 21.
Blind chamber body arrangement is found in:
(a) Sponges
(b) Annelids
(c) Coelenterates
(d) Mammals.
Answer:
(c) Coelenterates

Question 22.
Cephalopoda is a class of animals having:
(a) Notochord is elongated up to head
(b) Feet are found on the head
(c) Head is found on legs
(d) Head is jointed with cephalothorax.
Answer:
(c) Head is found on legs

Question 23.
Pearl oyster is associated with the class:
(a) Gastropoda
(b) Pelecypoda
(e) Schiphozoa
(d) Amphineura.
Answer:
(b) Pelecypoda

Question 24.
Eutherian mammals are:
(a) Oviparous
(b) Viviparous
(c) Ovi-viviparous
(d) Both (a) and (c).
Answer:
(b) Viviparous

Question 25.
Mesoglea is made up of:
(a) Amoeboid cell
(b) Nerve cell
(e) Nematocyst
(d) A cellular jelly
Answer:
(d) A cellular jelly

2. Fill in the blanks:

(A)
1. The skeleton of Porifera is chiefly formed of ………………
Answer:
Spicules

2. Shell of Mollusca is secreted by …………………
Answer:
Mantle

3. Physalia is popularly known as ………………….
Answer:
Portuguese man of war

4. ………………… fishes are exclusively marine.
Answer:
Cartilaginous

5. Pneumatic bones are found in …………………..
Answer:
Birds

6. Jointed appendages is the important characteristic of ……………… phylum.
Answer:
Arthropoda

(B)
1. Arthropoda is classified on the basis of wings and ………………..
Answer:
Appendages

2. Silverfish belongs to …………………
Answer:
Arthropoda

3. Heart of amphibians consists of …………………. chambers.
Answer:
Three

4. Bones of birds are …………………..
Answer:
Hollow

5. Most of the flat worms are anaerobes, this is ………………… adaptation.
Answer:
Parasitic

6. Starfish is ………………… symmetrical.
Answer:
Radially

7. Jointed legs are found in …………………… phylum
Answer:
Arthropoda

8. Excretory organs of earthworm are …………….
Answer:
Nephridia

9. Malpighian tubules are the ……………….. organs of insect.
Answer:
Excretory

10. Presence of hairs on the body surface is the characteristic features of class …………………..
Answer:
Mammalia

3. Match the following:

(A)

Answer:
1. (d) Tetrapoda.
2. (a) Echinodermata
3. (b) Mollusca
4. (c) Pisces

(B)

Answer:
1. (b) Aves
2. (c) Mammalia
3. (d) Nematoda
4. (a) Platyhelminthes

(C)

Answer:
1. (d) Hydra
2. (c) Starfish
3. (a) Aurelia
4. (e) Nereis
5. (b) Planaria

(D)

Answer:
1. (h) Osteichthyes.
2. (e) Annelida
3. (d) Reptilia
4. (a) Ctinophora
5. (b) Mollusca
6. (g) Mammalia
7. (c) Porifera
8. (f) Cyclostomata or Chonichthyes

4. Write true or false:

1. All major groups of animals have evolved in the sea.
Answer:
True

2. Exoskeleton is absent in Vertebrates.
Answer:
False

3. Snakes and Lizards shed their scales as skin cast.
Answer:
True

4. Toad skin is dry and warty and cannot absorb water.
Answer:
False

5. Flatworms are acoelomate organisms.
Answer:
True

5. Answer in one word:

1. The excretory organs in earthworm are.
Answer:
Nephridia

2. The process of transformation of a larva into an adult is called.
Answer:
Metamorphosis

3. The body fat of whale is called.
Answer:
Blubber

4. Malpighian tubules are the organs in insects.
Answer:
Excretory

5. The largest class of molluscs are.
Answer:
Gastropods

6. Write name of one bisexual animal of the phylum annelida.
Answer:
Hirudinaria (the cattle Leech)

Students get through the MP Board Class 11th Biology Important Questions Chapter 20 Locomotion and Movement which are most likely to be asked in the exam.

MP Board Class 11th Biology Important Questions Chapter 20 Locomotion and Movement

Locomotion and Movement Class 11 Important Questions Very Short Answer Type

Question 1.
What is arthritis?
Answer:
Arthritis is a disease characterized by the inflammation of the joints. In this disease, the synovial membrane secretes extra fluid which causes swelling and pain in the joints. A hard tissue deposits over the articular cartilages. As a result the joints become stiff.

Question 2.
What is muscle twitch?
Answer:
When a muscle fibre receives only one stimulus, then it contracts only one time. This one time contraction of muscle fibre is called as muscle twitch.

Question 3.
How many vertebrates and ribs are found in human?
Answer:
In human 26 vertebrates, and 12 pairs of ribs are found.

Question 4.
Name the longest bone of human body.
Answer:
Longest bone of human body is femur.

Question 5.
Write name of the locomotory organs of the following organisms :
(i) Paramoecium,
(ii) Hydra,
(iii) Earthworm,
(iv) Octopus,
(v) Starfish.
Answer:
(i) Cilia,
(ii) Tentacle,
(iii) Setae,
(iv) Muscular arm,
(v) Tube feet.

Question 6.
What is Sliding filament theory? (NCERT)
Answer:
Sliding filament theory was proposed by Lein. Muscle fibres contract and relax on being excited by the nerve fibres. According to this theory, during the contraction of muscle, actin filaments slide over the myosin filaments.

Locomotion and Movement Class 11 Important Questions Short Answer Type

Question 1.
What is joint? Name the joints related to the following organs :
(i) Joint of knee,
(ii) Joint between glenoid cavity of pectoral girdle and acetabulum cavity of pelvic girdle with the humerus and femur,
(iii) Elbow joint,
(iv) Joint between skull bones,
(v) Joint between carpals and metacarpals of thumb,
(vi) Ankle joint.
Answer:
Joint: The region at which two or more bones of skeleton come in contact and move freely is called as Joint.
(i) Hinge joint,
(ii) Ball and Socket joint,
(iii) Hinge joint,
(iv) Immovable joint,
(v) Saddle joint,
(vi) Hinge joint.

Question 2.
How movement takes place in skeleton by muscles?
Answer:
The skeleton of our body is connected with each other by voluntary muscles. The fibres that connect the bones with any muscle are known as tendon, whereas the fibres that connect bones to bones are known as ligaments. Muscle cells are made up of muscle fibres having the property of contraction and expansion hence muscle cells also possessing these characteristics. The contraction and expansion of these muscles resulting in the movement of skeleton.

Question 3.
Describe any four functions of the skeletal system.
Answer:
The skeletal system of vertebrates performing the following functions:

1. It protects the heart, brain and other soft organs.
2. It provides base to the body and gives a definite shape to it.
3. Skeletal system functioning like a pendulum and thus performing the process of movement and locomotion.
4. The thick bones of skeleton system synthesise R.B.Cs. and W.B.Cs. within their bone marrow.

Question 4.
From where energy is obtained for contraction of muscles?
Answer:
The energy for the contraction of muscle fibres is obtained from a chemical substance known as adenosine triphosphate (ATP) which is found in mitochondria. This sub¬stance is the source of energy required for the metabolic activities of cells. The energy obtained by the oxidation of glucose which is stored in ATP. Little glucose is present in muscle fibres but myosin is rich in ATP. When the muscle is excited, ATP itself changes into adenosine diphosphate (ADP), thereby releasing energy.
ATP → ADP + P04 + Energy
ADP is again converted into ATP by the energy obtained from the creatine phosphate. CP + ADP → ATP + C. Creatine is resynthesized into creatine phosphate by the energy ob¬tained from glucose of muscle glycogen.

Question 5.
Name various parts of human skeletal system and write number of bones found in them.
Answer:

Question 6.
Red muscle fibres functioning up to a longer period of time than white muscle fibres, why?
Answer:
Red muscle fibres contain a large amount of myoglobin and mitochondria. Myo¬globin combine with oxygen to form oxymyoglobin. For muscular contraction oxygen is derived from oxymyoglobin. These muscles do not respire anaerobically due to presence of oxygen and thus lactic acid is not formed. Thus, red muscle fibres functioning up to a longer period of time without fatigue. White muscle fibres do not contain myoglobin.

The number of mitochondria is also few. Hence oxygen supply becomes irregular and lactic acid is formed in these muscle fibres due to anaerobic respiration. Thus, these muscles become fatigue and they do not functioning up to a longer period of time.

Question 7.
What is meant by twitch muscle and tetanus?
Answer:
Twitch muscle: When a muscle receive only one stimulus then it contracts only one time. This one time contraction of muscle fibre is called as muscle twitch.
Tetanus : It is the permanent contraction condition of the muscle which occurs due to continuous conduction of impulse. This may lead to death of the person.

Question 8.
What is oxygen debt?
Answer:
Oxygen debt: After heavy work or exercise muscle do not get oxygen to fulfil their energy requirement. Thus, they produces ATP by anaerobic process, and lactic acid is formed. In this stage more oxygen is required than normal stage. This requirement of extra quantity of oxygen is called as oxygen debt.

This extra oxygen is used up by the lactic acid for its aerobic oxidation. By this process creatine phosphate is produced. Some quantity of required oxygen is supplied by myoglobin which has capacity to store oxygen for future. During training of athletes rate of oxy- contraction of muscle is increased. Thus, athletes required less oxygen debt.

Question 9.
Write differences between Fixed joint and Synovial joint.
Answer:
Differences between Fixed joint and Synovial joint

Question 10.
Draw diagram showing one sarcomere of the striped muscle and label its various parts. (NCERT)
Answer:

Question 11.
How will you differentiate skeletal muscle and Cardiac muscle? (NCERT)
Or,
Write differences between Striped, Unstriped and Cardiac muscles.
Answer:
Differences between Striped, Unstriped and Cardiac muscles

Question 12.
Draw a labelled diagram of pelvic girdle of human.
Answer:

Question 13.
Name the type of joints found in the following : (NCERT)
(a) Atlas and axis,
(b) Carpal and metacarpal of thumb,
(c) Between phalanges,
(d) Femur and acetabulum,
(e) Between bones of skull,
(f) Between pubic bones of pelvic girdle.
Answer:
(a) Pivot joint,
(b) Saddle joint,
(c) Hinge joint,
(d) Ball and socket joint,
(e) Fibrous joint (sutures),
(f) Cartilaginous joint.

Locomotion and Movement Class 11 Important Questions Long Answer Type

Question 1.
Write the differences between following : (NCERT)
(a) Actin and Myosin
(b) Red muscle fibre and White muscle fibre
(c) Pectoral and Pelvic girdle.
Answer:
(a) Differences between Actin and Myosin filament

(b) Difference between Red and White muscle fibres

(c) Differences between Pectoral and Pelvic girdle

Question 2.
Describe main steps of muscular contraction. (NCERT)
Or,
Draw a labelled diagram of striped muscle and describe mechanism of muscular contraction in brief.
Answer:
Structure of striped or voluntary muscles: Since their movement is always at the will of the animal possessing them, they are known as voluntary muscles. They are always attached with the skeleton, hence called as skeletal muscles. Their cells are long and tubular and each is surrounded by thin membrane called sarcolemma. Many nuclei are found in the sarcoplasm surrounded by sarcolemma; therefore, muscular tissue is multinucleated or syncytial. A large number of parallel myofibrils are present in the sarcoplasm.
Transverse bands of light and dark shade are found in each muscle fibres. Dark bands are known as ‘A’ discs or Dobie’s dots while light bands are called ‘I’ discs. Each ‘I’ disc is divided into two another band known as ‘Z’ disc or Krause’s membrane. Similarly ‘A’ disc is also divided into two parts by Hensen’s disc or ‘H’ zone. The part between two ‘Z’ discs is known as sarcomere.

Electron microscopic studies have shown that these bands are formed of protein. ‘A’ bands are formed of parallel bars of a protein called myosin. ‘I’ bands are made up of similar bars of a protein known as actin. The muscles lengthen and shorten due to the contraction and expansion of these bars. These muscles take main part in the movement of organs as limbs, neck, eye etc.

Working of striped muscle fibre: The muscle fibres contract and relax on being excited by the nerve fibres. H.E. Huxley and A.F. Huxley explained the working of muscle fibres with the help of electron microscopic studies. The theory proposed by Lein is known as sliding filament theory. It says that during contraction the actin filaments slide over the myosin filaments. There is no change in the length of ‘A’ bands at the time of contraction.

The actin bars of T bands slide on the myosin bars of ‘A’ bands and come so close that they overlap each other in the region of Hensen’s discs. Thus the muscle fibres contract due to the shortening of sarcomeres. The muscle fibres remain in their normal state when the effect of excitation is over, i.e. actin and myosin bars come back in their normal position. The sarcomeres are the functional units of striped muscle fibres.

Question 3.
What are joints? Describe the various types of joints found in human beings Or, What is joint ? Describe perfect joint and explain any three types of it.
Answer:
Joints: The region at which two or more bones of skeleton come in contact and move freely is called as joint.
Basically three types of joints are found in the body or vertebrates :

1. Perfect joints,
2. Imperfect joints,
3. Immovable joints.

1.Perfect joints: These joints have synovial cavity which allow movement in more than one plane. The perfect joints may be of following types :

(a) Bail and Socket joint: Arthritis is a disease characterized by the inflammation of the joints. In this disease, the synovial membrane secretes extra fluid which causes swelling and pain in the joints. A hard tissue deposits over the articular cartilages. As a result the joints become stiff.

(b) Pivot joint: In this joint the articulating face of one bone is stationary like a pivot while the articulating face of the other can rotate over it. e.g. Joint between carotae and vertebral column.

(c) Hinge joint: It is just like a hinge of a door, allowing movement in one plane, e.g. Elbow joint, knee joint, ankle joint.
(d) Gliding joint : In such joint the articulating surface of the bone can glide one above the other, e.g. Joint between radio ulna and carpal.

(e) Saddle joint: It resembles the ball and socket joint except that in this case neither the ball nor the socket is fully developed, e.g. Metacarpal of the thumb joining the wrist bone in man.

2. Imperfect joint: These joints which do not possess synovial cavity or connecting ligaments are called imperfect joints, e.g. Joints between ileum of pelvic girdle and transverse process of sacral vertebrae.

3. Immovable joint: These joints which are permanently fixed and cannot perform any movement are termed as immovable joints, e.g. Bones of skull. These joints are called sutures. These joints lack synovial capsule.

Question 4.
What is Axial Skeleton? Describe various bones of Axial skeleton of human.
Answer:
Axial Skeleton: Skeleton which forms axis of the body is called as Axial skeleton. It consists of skull, Hyoid, vertebral column and ribs.
1. Skull: It is formed of 28 bones and is skeleton of the head region. Skull can be further divided into following regions :
(i) Cranium or brain box: It encloses the brain and is formed of eight bones namely frontal, parietal (two), temporal (two), occipital, sphenoid and ethmoid.

(ii) Facial bones : These form facial part of the skull and are fourteen in number. These include nasal 2, maxillary 2, squamosal 2, mandible 1, lachrymal 2, palatine 2, turbinals 2 and vomer 1.

(iii) Ear bones: These are three pairs of ear ossicles : malleus 2, incus 2 and stapes 2.
2. Hyoid: It supports tongue.
3. Vertebral column: It forms axis of the body and also known as backbone. Vertebral column supports the body like a beam. It is slightly curved vertical rod in the mid dorsal line of the body extended from the atlas vertebra to the caudal vertebra. Vertebral column protects the general viscera and houses the spinal cord also.
Vertebral column develops from the notochord part of the embryo. Total number of vertebrae in the vertebral column of human being is 26, however in primitive stage it is 33 in number. Vertebral column is differentiated into five regions, which are :

• Cervical vertebrae,
• Thoracic vertebrae,
• Lumbar vertebrae,
• Sacral vertebrae,
• Caudal vertebrae.

4. Sternum and ribs: It forms the floor of thoracic basket and supports anterior part of chest. Sternum has three parts manubrium, body and xiphoid process. 12 pairs of ribs are associated with the sternum.
Functions :
(i) Ribs form thoracic cavity along with sternum and vertebral column.
(ii) It protects lungs and heart.
(iii) These help in breathing.

Question 5.
What are Appendicular skeleton? Explain the bones of appendicular skeleton in man.
Answer:
Appendicular Skeleton: It is formed of bones appended to axial skeleton i.e., pectoral girdle, pelvic girdle and associated limbs.
Girdles: It consists of two types :
1. Pectoral girdle : It is found in the shoulder region where forelimbs join with it at the glenoid cavity. It is generally a duplex structure and functions as an intermediary structure through which the weight of the body is transferred to the forelimbs. Pectoral girdle is formed of two bones, scapula (2) and clavicle (2).

2. Pelvic girdle: It provides articulation with bones of hind limbs at acetabulum cavity. It has two halves, each half has three main bones ilium dorsal in position, ischium and pubis ventral in position. Each half of the girdle forms innominate bones or osinnominatum.

3. Limbs: These are meant for locomotion in tetrapod vertebrates. Limbs are differentiated into:
(i) A pair of forelimbs,
(ii) A pair of hind limbs.
(i) Forelimb : Forelimbs are attached to the pectoral girdle. Each forelimb has upper arm, forearm and hand. There are 30 bones in each forelimb namely, humerus in the upper arm, radius and ulna in forearm, eight carpals in the wrist, five metacarpals in the palm and 14 phalanges in the fingers of the hand.

(ii) Hind limbs : Hind limbs are attached to the pelvic girdle. Each hind limb has thigh, shank and foot. There are thirty bones in each hind limb namely, femur in the thigh, patella in the knee, tibia and fibula in the shank, 7 tarsals in the ankle, 5 metatarsals insole and 14 phalanges in the toes of the foot.

Locomotion and Movement Class 11 Important Questions Objective Type

1. Choose the correct answers:

Question 1.
Synovial joints are found between :
(a) Two vertebrae
(b) Two skull bones
(c) Humerus and ulna
(d) Caudal vertebrae.
Answer:
(c) Humerus and ulna

Question 2.
The fluid present in ball and socket joints and which reduces the friction is:
(a) Pericardial fluid
(b) Mucin
(c) Synovial fluid
(d) Coelomic fluid.
Answer:
(c) Synovial fluid

Question 3.
The number of vertebrae in human is :
(a) 30
(b) 31
(c) 32
(d) 33.
Answer:
(d) 33.

Question 4.
Hinge joint is found between :
(a) Radius ulna and humerus
(b) Femur and acetabulum
(c) Humerus and acetabulum
(d) None of these.
Answer:
(a) Radius ulna and humerus

Question 5.
The muscle fatigue is due to accumulation of:
(a) Lactic acid
(b) CO₂
(c) Acetic acid
(d) Sulphuric acid.
Answer:
(b) CO₂

Question 6.
The articulation of femur and pelvic girdle is an example of:
(a) Ball and socket joint
(b) Pivot joint
(c) Hinge joint
(d) None of these.
Answer:
(a) Ball and socket joint

Question 7.
Which one is the contractile protein of a muscle :
(a) Actin
(b) Myosin
(c) Tropomyosin
(d) Globulin.
Answer:
(a) Actin

Question 8.
Our wrist joint is a :
(a) Sliding
(b) Hinge joint
(c) Pivot
(d) Fixed joint.
Answer:
(a) Sliding

Question 9.
The joint between the lower jaw and skull is :
(a) Perfect joint
(b) Hinge joint
(c) Gomphoses
(d) Gliding joint.
Answer:
(c) Gomphoses

Question 10.
Ends of long bones are covered with.
(a) Cartilage
(b) Muscles
(c) Ligaments
(d) Blood cells.
Answer:
(a) Cartilage

2. Fill in the blanks:

(A)
1. ……………… joint is found in the bones of skull.
Answer:
Immovable joint,

2. Skeletal movement takes place due to ……………… muscles.
Answer:
voluntary muscles,

3. ……………… is the smallest bone of the human body.
Answer:
Stapes,

4. Myoglobin stores ……………… .
Answer:
Oxygen,

5. Haversian system is found in ……………… .
Answer:
Bones,

6. Bone is made of ……………… protein and cartilage is made up of ……………… protein.
Answer:
Ossein, Chondrin,

7. ……………………… element is essential for the constriction of muscles.
Answer:
Ca⁺⁺

8. Total ………………………  bones are found in the body of an adult human being.
Answer:
206.

(B)
1. In all vertebrates except few ……………… cervical vertebrates are found.
Answer:
7

2. In the fine fibre of myofibril 2 ‘F’ actin and two other proteins ……………… and ……………… are found.
Answer:
Tropomyosin, Troponin

3. In each human limb number of phalanges is ……………… .
Answer:
14,

4. In muscle fibre calcium is stored in the ……………… .
Answer:
Sarcoplasmic reticulum,

5. Cranium of human consists of ……………… bones.
Answer:
8.
3. Match the following:

(A)

Answer:
1.  (c) Tentacles,
2. (d) Tube feet
3. (e) Pseudopodia.,
4. (a) Cilia
5. (b) Setae

(B)

Answer:
1.  (b) Ball and Socket joint
2.  (c) Hinge joint
3. (d) Bone-bone
4. (e) Bone-muscle.
5. (a) Ear

(C)

Answer:
1. (d) Involuntary.,
2. (b) Fine fibre
3. Myoglobin
4. (a) Myoglobin.

4. Write true or false:

1. Actin is located in the fine fibre.
Answer:
True,

2. H-zone of striped muscle represents both thin and thick fibre.
Answer:
True,

3. Human skeleton consists of 206 bones.
Answer:
True,

4. Inhuman 11 pairs of ribs are found.
Answer:
False,

5. Sternum lies in the ventral surface of the body.
Answer:
True.

5. Answer in one word :

1. Name the joint found between humerus and radius ulna.
Answer:
Hinge joint,

2. What is the number of vertebrae and ribs in human being?
Answer:
33, 24,

3. Where is glenoid cavity found?
Answer:
In shoulder region,

4. Where is acetabulum found?
Answer:
In articulation of hind limbs,

5. Give one-one example of the following :
(a) Ball and socket joint,
(b) Immovable joint.
Answer:
(a) shoulder and hip joint
(b) Bones of the skull.

6. How many bones are there in human body?
Answer:
206

7. Name the smallest bone in human body. ‘
Answer:
Stapes

8. Name the longest bone in human body.
Answer:
Femur

9. Name the locomotory organ of Amoeba & starfish.
Answer:
Pseudopodia, Tube fee

Students get through the MP Board Class 11th Biology Important Questions Chapter 3 Plant Kingdom which are most likely to be asked in the exam.

MP Board Class 11th Biology Important Questions Chapter 3 Plant Kingdom

Plant Kingdom Class 11 Important Questions Very Short Answer Type

Question 1.
Draw a well labelled diagram of the Archegonia of Moss plant.
Answer:
Archegonia of Moss : (Female reproductive organ)

Question 2.
What do you understand by protonema?
Answer:
Juvenile forms (Protonema) :
It is a green branched filamentous structure. From green aerial filaments produced some branches which grows below substratum and are without chloroplasts are known as rhizoidal branches. They penetrate the soil and help in absorption of water and minerals. Several buds develops on protonema and each bud develops into leafy gametophore.

Question 3.
What do you understand by Mycorrhiza?
Answer:
It is a type of symbiotic association which is found in Pinus plant in between roots and fungi in which on outer side of root safety shell is present. Fungus absorbs water, mineral and protein for plants and in return from plants, it gets nutrition.

Question 4.
What do you understand by Apospory?
Answer:
Sometime the cells of sparophytes get separated from mother plant and fall on soil, where they germinate and form protonema. Sometime on top of protonema a leafy gametophore is formed from which a new plant is formed in which all the cells have double characters. Thus the protonema formed from the cell of sporophyte without division gametophyte develops. This is known as Apospory.

Question 5.
What do you understand by sulphur shower?
Answer:
At maturity, the microsporophylls separate and spread apart. The sporangia dehisce by longitudinal slit and shed large quantities of pollen grains. Since pollen grains flow in colour and are discharged in such a large number that their shedding is referred to as sulphur shower.

Question 6.
Give economic importance of Brown algae.
Answer:

• It is food for Japanese.
• More than 30% of dry weight of brown algae is KCl (Potassium chloride).
• Vitamin B, acetic acid and iodine are obtained from brown algae.
• Alginic acid obtained from sea kelps are used as thickeners in making ice-cream, cosmetics and in textile industries.

Question 7.
Name the algae from which agar-agar is obtained.
Answer:
Agar-agar is obtained from Grasillaria and Galidum.

Question 8.
Why Spirogyra is called as Pond silk?
Answer:
Pectin layer present outer to the cellulose cell wall of Spirogyra dissolves in water to form a mucilaginous sheath. Thus Spirogyra became slippery, after drying looks like a silk thread, that is why it is called as pond silk.

Question 9.
Name two algae used as food.
Answer:

1. Laminaria,
2. Porphyra.

Question 10.
Name the algae which causes rust of tea disease.
Answer:
Cephalurous algae.

Question 11.
Who is regarded as ‘Father of Indian Phycology’ in India?
Answer:
Indian scientist M.O.P. Iyengar is regarded as Father of Indian Phycology.

Question 12.
What is thallus?
Answer:
Plant which cannot be differentiated into root, stem and leaves are called as thallus.

Question 13.
Which terrestrial plants are primitive?
Answer:
Terrestrial plants of pteridophyta are primitive.

Question 14.
In which part of the fern plant sporangium is found ?
Answer:
In the sporophyll part of the leaves of fem plant sporangiums are found.

Question 15.
Give two fern like characteristics of Cycas plant of gymnosperm.
Answer:

1. Both are vascular plants,
2. Main plant is sporophytic.

Question 16.
Name the plant which produces largest flower.
Answer:
Rafflesia plant produces largest flower.

Question 17.
Give three examples of gymnosperms found in India.
Answer:

1. Pinus,
2. Cycas,
3. Cedrus deodara.

Question 18.
Give two important features of Angiosperms.
Answer:

1. They are flowering plants,
2. Seeds are formed within the fruit.

Question 19.
Give two medicinal importance of algae.
Answer:

• Vitamin B is obtained from Laminaria,
• Iodine is obtained from Kelps.

Plant Kingdom Class 11 Important Questions Short Answer Type

Question 1.
Where and when reduction division occurs in liverwort, moss, fern, gymnosperms and angiosperms? (NCERT)
Answer:
In liverwort, moss, fem and gymnosperms reduction division occurs in the spore mother cell to produce haploid spores.
In Angiosperms reduction division occurs during formation of pollen grains in the pollen sac of the stamen and during formation of embryo sac in the ovule of carpel.

Question 2.
Give ploidy of following :

1. Protonemal cell of Moss,
2. Nucleus of primary endosperm of Moss,
3. cells of leaves of Moss,
4. cells of Fern prothallus,
5. Gemma cells of Marchantia,
6. Meriste- matic cell of monocot plant,
7. Ovum of Liverwort,
8. Zygote of Fern. (NCERT)

Answer:

1. Protonemal cell of Moss – Haploid
2. Nucleus of primary endosperm of Moss – Triploid
3. Cells of leaves of Moss – Diploid
4. Cells of Fem prothallus – Haploid
5. Gemma cells of Marchantia – Haploid
6. Meristematic cell of monocot plant – Diploid
7. Ovum of Liverwort – Haploid
8. Zygote of Fem – Diploid.

Question 3.
Both Gymnosperms and Angiosperms produce seeds, inspite of that they are classified into different groups, why? (NCERT)
Answer:
Both Gymnosperms and Angiosperms produces seeds, inspite of that they are classified into different groups because seeds of gymnosperm are naked whereas seeds of angiosperms are formed within the fruit.

Question 4.
Draw a well-labelled diagram of moss capsule showing internal structure.
Answer:

Question 5.
What is Heterospory? Write a note on it and give two examples.
Answer:
Heterospory : Formation of two different types of spores, such as small microspores and large megaspores is called as Heterospory.
First of all heterospory was observed in Selaginella. It is also observed in Salvinia.
Megaspore (female) and microspore (male) develop to produce female and male gametophytes respectively.
Female gametophyte remains attached to sporophytic plant to fulfil its requirement.

Question 6.
Write economic importance of algae and gymnosperms.
Answer:
Economic importance of algae :
(A) Economic importance of Red algae :

• Agar : Agar is obtained from Gelidium and Gracilaria, which is mainly used in production of medium for culturing bacteria.
• Agar is used as laxative factor to prepare medicine.
• Some species of red algae are used in preparation of pudding, ice-cream, cheese, salad decoration etc.
• Irish agar obtained from Chondrus crispes, is used in preparation of chocolate.

(B) Economic importance of Brown algae :

• It is food for Japanese.
• More than 30% of dry weight of brown algae is KCl (Potassium chloride).
• Vitamin B, acetic acid and iodine are obtained from brown algae.
• Alginic acid obtained from sea kelps are used as thickeners in making ice-cream, cosmetics and in textile industries.

(C) Economic importance of Gymnosperms :

• It provides timber wood and firewood.
• Some plants are used as ornamental plants, such as Cycas, Pinus etc.
• Sago is obtained from Cycas.
• Many medicines are obtained from different species of gymnosperms, such as ephedrine medicine is obtained from Ephedra species.
• From some species of gymnosperms edible oil is obtained.
• Leaves of Cycas are used in making broom and rope.
• Some conifers are used in making paper.

Question 7.
Write four characteristics of Chlorophyta.
Answer:
Characteristics of Chlorophyta :

1. Photosynthetic pigment in green algae are chlorophyll-a, chlorophyll-b, β -carotene and Xanthophyll.
2. Cell wall is made up of cellulose.
3. Ciliated Zoospores are formed which are motile.
4. Stored food is starch.
5. Sexual reproduction ranges from isogamy to oogamy. e.g., Spirogyra, Ulothrix, Sargassum etc.

Question 8.
Give important characteristics of Angiosperms.
Answer:
Characteristics of Angiosperms :

• Plant body is differentiated into root, stem and leaves.
• Reproductive organs are flower having four whorls : Calyx, corolla, androecium and gynoecium.
• Ovules are covered within ovary.
• The ovary ripe into fruit which contains seeds.
• Vascular bundles are well developed.
• Double fertilization occurs in them.
• They may be parasitic (e.g., Cuscuta), Saprophytic (e.g., Orobanche), epiphytic (e.g., Orchid), insectivorous (e.g., Nepenthes) and antotrophic.
• They are well adapted for their environment. e.g., Mango, rose, wheat, rice etc.

Question 9.
Give important characteristics of Bryophyta.
Answer:
Characteristics of Bryophyta :

• Main plant is gametophytic.
• There is complete absence of true root, stem and leaves.
• Plant body is bilaterally symmetrical, branched and leaf like which bears Rhizoids on the ventral surface. They contain chlorophyll.
• They are non-vascular amphibian plants.
• Sporophyte partly depends on gametophyte.
• Reproductive organs are multicellular and found surrounded by jacket layer. Water is required for fertilization.
• They shows alternation of generation. e.g., Funaria, Riccia, Marchantia etc.

Question 10.
Write similarities between Gymnosperms and Angiosperms.
Answer:
Similarities between Gymnosperms and Angiosperms :

• Both are perennial plants.
• Both produces special reproductive organs.
• In both, main plant is sporophytic.
• In both, gametophyte depend on sporophyte.
• Both produces seeds.
• In both, ovules develop to form seeds.
• Both shows alternation of generation.

Plant Kingdom Class 11 Important Questions Long Answer Type

Question 1.
Name three groups of plants in which Archegonium is found. Describe Life cycle of any one of them. (NCERT)
Answer:
In following three groups of plants Archegonium is found :

1. Bryophyta,
2. Pterydophyta,
3. Gymnosperms.

Life Cycle of Bryophyta (Funaria):
In the life history of mosses two generations viz, gametophyte and sporophyte are found which regularly alternate with each other. The dominant phase is represented by the gametophyte which is haploid (n) and it reproduces sexually by the fusion of gametes (antherozoids and ovum) give rise to the sporophyte which is diploid structure (2n). Meiotic division takes place in the capsule of sporophyte during sporogenesis to form spores. These spores germinate to producer new gametophyte.

Question 2.
Write differences between Gymnosperms and Angiosperms.
Answer:
Differences between Gymnosperms and Angiosperms

Question 3.
Write differences between Pteridophytes and Bryophytes.
Answer:
Differences between Pteridophytes and Bryophytes

Question 4.
Explain following terms with example:
(i) Protonema,
(ii) Antheridium,
(iii) Archegonium,
(iv) Dipiontic,
(v) Sporophyll,
(vi) Isogamy. (NCERT)
Answer:
(i) Protonema :
It is the first stage of life cycle of Moss (Funaria). It is formed by germination of haploid spore. Protonema is multicellular, branched structure which contain chlorophyll, thus are autotrophs.

(ii) Antheridium:
Male reproductive organ of Bryophyta and Pterydophyta are called as Antheridium. It produces biflagellate spermatozoids or antherozoids.

(iii) Archegonium :
Female reproductive organ of Bryophyta and Pterydophyta are called as Archegonium. It is multicellular flask shaped structured, which produces haploid
egg.

(iv) Dipiontic :
In this mode of reproduction and life cycle, adults have diploid set (2x) of chromosome. During sexual reproduction (2x) individuals produces haploid (x) gametes by meiosis cell division which fuses to form diploid zygote (2x). This diploid zygote grows to form adult.
e.g., Life cycle of Saccharomycod.es ludurigii.

(v) Sporophyll:
In Pterydophytes leaves on which sporangium are formed called as Sporophyll. e.g., Fern.

(vi) Isogamy :
Similar gametes which fuses together to form zygote are called as Isogamy. e.g., Chlamydomonas.

Question 5.
Write differences between Monocot and Dicot plant.
Answer:
Differences between Monocot and Dicot Plant

Question 6.
Differentiate following :
(i) Red algae and Brown algae,
(ii) Liverwort and Moss,
(iii) Heterosporous and Homosporous pteridophytes,
(iv) Syngamy and Triple fusion, stem and leaves.

(i) Red algae and Brown algae :
Red alage:

• They are red in colour due to presence of pigments called phycobillins mainly phycocyanin and phycoerythrin.
• There is complete absence of motile stages in life.
• Stored food is floridian starch.
• Cell wall consists of cellulose pectic compounds and mucopolysaccharides.
• Sexual reproduction is Oogamous type.
  e.g., Porphyra, chordrus.

Brown algae :

• They are brown coloured due to presence of xanthophyll, fucoxanthin. In addition to this accessory pigments are chl-a, chl-c, β and C carotene are also found.
• Flagellate Zoospores are formed during reproduction which are motile.
• Stored food is manitol, laminarin and lipid.
• Cell wall is double layered. Inner layer consists of cellulose and outer layer is a gelatenous substance known as phycocolloids, alginic acid.
• Sexual reproduction varies from isogamy, anisogamy to oogamy.
  e.g., Laminaria, Macrocystis, Sargassum.

(ii) Liverwort and Moss :

• Rhizoid of liverwort is non-septate whereas Rhizoids of moss is septate.
• Gametophyte of liverwort is thallus flat leaf like whereas moss gametophyte is differentiated into rhizoid, stem and leaf like structure.
• Leaves of liverwort are not arranged in spiral way whereas leaves of moss are spirally arranged.
• lators are found in liverwort for dispersal of spores whereas elators are not found in moss.
• Liverwort belongs to group Hepaticeae whereas moss belongs to group Musci.

(iii) Heterosporous and Homosporous pteridophytes:
Heterosporous pteridophytes produces two types of spores Megaspores and microspores such as Selaginella, whereas Homosporous pteridophytes produces all similar sized spores such as Lycopodium.

(iv) Syngamy and Triple fusion :
In Angiosperms, process of fusion of first male gamete with haploid egg to produce a diploid zygote is called as Syngamy. Zygote develops to form embryo, whereas fusion of secondary nuclei and second male gamete to produce a triploid body is called as Triple fusion. Triploid body develops to produce endosperm.

Question 7.
Write important characteristics of gymnosperms.
Answer:
Characteristic features of Gymnosperms:

• Plants are perennial, woody trees or shrubs and xerophytic in nature.
• This subdivision includes vascular, naked seed plants.
• Plants are sporophytic which are differentiated into root, stem and leaves.
• Vascular bundle consists of xylem and phloem but the xylem is devoid of vessels and phloem that of companion cells.
• Reproductive parts borne in the form of cones or strobilus.
• Male cone contains several microsporophylls with microsporangia on their undersurface. Female cone contains many megasporophylls with one to several naked ovules.
• Inside the microsporangia microspores or pollen grains are formed by meiosis division of special cells, which germinate to produce male gametes.
• Female gametophyte develops inside the ovule and contains two or more arche-gonia at the anterior end.
• Pollination is anemophilous (wind pollinated).
• Pollen grain germinates to form pollen tube on female cone after pollination and produces male gametes which fuses with female gamete to form zygote. Embryo develops from zygote and ovule along with embryo forms seed, which germinate to form new plant.
• Secondary growth is present.
• Usually polyembryony is found in seed.
• Archegonia lack neck canal cells.
• Embryo bears two or more cotyledons.

Plant Kingdom Class 11 Important Questions Objective Type

1. Choose the correct answers:

Question 1.
Dominant stage of bryophytes is :
(a) Haploid
(b) Diploid
(c) Both are similar
(d) None of these.
Answer:
(a) Haploid

Question 2.
Zoospores are formed from :
(a) Asexual reproduction
(b) Sexual reproduction
(c) Amitotic division
(d) Mitosis.
Answer:
(a) Asexual reproduction

Question 3.
In the life history of Spirogyra, meiosis takes place during :
(a) The formation of gametes
(b) The formation of zoospores
(c) The germination of zygote
(d) The formation of zygote.
Answer:
(c) The germination of zygote

Question 4.
Habitat of mosses is :
(a) Dry place
(b) Fresh water
(c) Non-salty water
(d) Moist and shadow places.
Answer:
(d) Moist and shadow places.

Question 5.
Sperms of moss is:
(a) Uniflagellate
(b) Biflagellate
(c) Multiflagellate
(d) Non-motile.
Answer:
(b) Biflagellate

Question 6.
Mosses are found in moist and shadowy places because of the :
(a) Absence of vascular tissue
(b) Requirement of water for fertilization
(c) Absorption of water through general body surface
(d) All of these.
Answer:
(c) Absorption of water through general body surface

Question 7.
Female reproductive organ of Funaria is known as :
(a) Sporangium
(b) Spermatium
(c) Archegonia
(d) Sporophyll.
Answer:
(c) Archegonia

Question 8.
Sperms reach archegonia through :
(a) Air
(b) Water
(c) Animals
(d) Insects.
Answer:
(b) Water

Question 9.
Mosses will not be larger because of the :
(a) Absence of vascular tissue
(b) Presence of vascular tissue
(c) Absence of flower
(d) Absence of seeds.
Answer:
(a) Absence of vascular tissue

Question 10.
Fern prothallus is :
(a) Haploid
(b) Diploid
(c) Triploid
(d) Sporophyte.
Answer:
(a) Haploid

Question 11.
Shape of the prothallus is :
(a) Rounded
(b) Elongated
(c) Heart like
(d) Polygonal.
Answer:
(c) Heart like

Question 12.
Ferns are highly developed than mosses because of the :
(a) Presence of vascular tissue
(b) Dominance of sporophyte
(c) Root, stem and leaves are well developed
(d) All of these.
Answer:
(d) All of these.

Question 13.
Prothallus is:
(a) An independent structure
(b) A dependent structure
(c) Depend on gametophyte
(d) Depend on sporophyte.
Answer:
(a) An independent structure

Question 14.
In Spirogyra :
(a) Sexual reproduction between two adjacent cells
(b) Variable biflagellate antheridium and oogonium
(c) Sexual reproduction between various substances of a cell.
(d) Only sexual reproduction.
Answer:
(a) Sexual reproduction between two adjacent cells

Question 15.
Funaria possessing :
(a) Unicellular simple rhizoids
(b) Tuberculated rhizoids
(c) Differentially branched rhizoids
(d) Multicellular oblique rhizoids.
Answer:
(a) Unicellular simple rhizoids

Question 16.
Number of peristome teeth in the capsule of Funaria is :
(a) 4 in one ring
(b) 32 in two rings
(c) 16 in one ring
(d) 16 in two rings.
Answer:
(b) 32 in two rings

Question 17.
Type of gametes fused during sexual reproduction in Spirogyra is :
(a) Two identical motile gametes
(b) Two identical non-motile gametes
(c) One motile and one non-motilé gametes
(d) Two different non-motile gametes.
Answer:
(d) Two different non-motile gametes.

Question 18.
Cell of Funaria in which reduction division occur, is:
(a) Antheridial cell
(b) Archegonial cell
(c) Gametic cell
(d) Spore mother cell.
Answer:
(d) Spore mother cell.

Question 19.
Algae producing agar-agar is:
(a) Spirogyra and Nostoc
(b) Gracilaria and Gelidium
(d) Rivularia and Ulothrix.
(c) Volvox and Vaucheria
Answer:
(b) Gracilaria and Gelidium

Question 20.
Ulothrix is found in :
(a) Floating freshwater
(b) Floating marine water
(d)Pure marine water.
(c) Pure freshwater
Answer:
(a) Floating freshwater

Question 21.
In Funaria, stomata are found in
(a) Leaves
(b) Stem
(c) Theca
(d) Apophysis.
Answer:
(d) Apophysis.

Question 22.
Gametophyte of Funaria is :
(a) Monoecious
(b) Dioecious
(c) Both (a) and (b)
(d) Heterothallic.
Answer:
(a) Monoecious

Question 23.
In Pteridophytes, meiosis takes place :
(a) Sporogenesis
(b) Gametogenesis
(c) Prothallus formation
(d) Sex organ formation.
Answer:
(a) Sporogenesis

Question 24.
Cell wall of Spirogyra is made up of:
(a) Cellulose
(b) Pectin
(c) Lignin
(d) Chitin.
Answer:
(a) Cellulose

Question 25.
Ribbon like chloroplast is found in :
(a) Ulothrix
(b) Spirogyra
(c) Oedogonium
(d) Marc hantia.
Answer:
(a) Ulothrix

Question 26.
Main stage or dominant stage of bryophyta is :
(a) Gametophyte
(b) Cone Pinus
(c) Spore
(d) Hormogonium.
Answer:
(a) Gametophyte

Question 27.
Pinus species is :
(a) Monoecious
(b) Dioecious
(a) Chlorophyll-a
(c) Chlorophyll-c
Answer:
(b) Dioecious

Question 28.
Pigment found in green plant is:
(a) Chlorophyll-a
(b) Chlorophyll-b
(c) Chlorophyll-c
(d) Chlorophyll-m.
Answer:
(a) Chlorophyll-a

Question 29.
Life cycle of spirogyra is :
(a) Haploid
(b) Diploid
(c) Haplontic
(d) Diplontic.
Answer:
(c) Haplontic

Question 30.
Pinus is:
(a) Deciduous
(b) Dioecious
(c) Monoecious
(d) None of these.
Answer:
(c) Monoecious

Question 31.
In Funaria spore produces :
(a) Primary protonema
(b) Prothallus
(c) Proembryo
(d) Embryo.
Answer:
(a) Primary protonema

Question 32.
Meiotic division takes place in the zygote of :
(a) Selaginella
(b) Spirogyra
(c) Pinus
(d) Equisetum.
Answer:
(b) Spirogyra

Question 33.
In which meiosis does not occur :
(a) Green algae
(b) Fungi
(c) Bacteria
(d) Higher plants.
Answer:
(c) Bacteria

Question 34.
Non-motile gametes are found in:
(a) Spirogyra
(b) Ulothrix
(c) Funaria
(d) None of these.
Answer:
(a) Spirogyra

Question 35.
In Funaria plant stomata are present in :
(a) Foot
(b) Seta
(c) Capsule
(d) Leaf.
Answer:
(c) Capsule

2. Fill in the blanks:

1. The red colour of red algae is due to ………………..
Answer:
Phycoerythrin

2. The ………………… act as soil binders and prevent soil erosion.
Answer:
Mosses

3. The ……………… shoot of Pinus has limited growth.
Answer:
Dwarf

4. Phycology is known as the study of ………………..
Answer:
Algae

5. ………………… is given a nick name of pond scum.
Answer:
Spimgyra

6. Effective independent sporophytes are found in ……………….. group of plants.
Answer:
Tracheophyta

7. ……………….. are called as naked seed plants.
Answer:
Gymnosperms

8. Reproductive organs of ………………… are multicellular.
Answer:
Embryophyta

9. In …………………. polyembryony is found.
Answer:
Cycas

10. Life cycle of Funaria begins from ………………
Answer:
Haploid spore

11. In ………………… vascular tissues are not found.
Answer:
Bryophyta

12. …………………. are called as sea weeds.
Answer:
Brown algae

13. Heart shaped haploid independent structure of pterydophyta is called as …………………..
Answer:
Prothallus

14. In ………………… plants seed develops within the fruit.
Answer:
Angiosperms

15. In two kingdom classification algae and fungi are kept in …………….. group.
Answer:
Thallophyta

16. Algae found in the form of colony of cells is called as ………………….
Answer:
Volvox

17. Spimgyra belongs to class ………………..
Answer:
Chlorophyceae

18. ………………… are amphibian plants.
Answer:
Bryophytes

19.In angiosperms ……………… fertilization occurs.
Answer:
Double

20. Main plant of pterydophyta is ………………………
Answer:
Sporophytic

3. Match the following:

(A)

Answer:
1. (c) First terrestrial plant
2. (d) Pinus.
3. (a) Amphibian plants
4. (b) Not differentiated into root, leaf etc.

(B)

Answer:
1. (c) Marine algae
2. (d) Algae.
3. (b) Funaria
4. (a) Starch

(C)

Answer:
1. (d) Thallophyta.
2. (c) Non-flowering plants
3. (b) Bryophytes
4. (a) Flowering plants

(D)

Answer:
1. (c) Red algae
2. (e) Fungi.
3. (b) Alternation of generation
4. (a) Mycelium
5. (d) Bryophyta

(E)

Answer:
1. (c) Algae
2. (d) Gymnosperms.
3. (b) Pterydophyta
4. (a) Musci

4. Write true or false:

1. Bryophytes are found in marshy place not in water.
Answer:
False

2. Selaginella is a heterosporous pteridophyte.
Answer:
True

3. Mucor is a saprophytic fungi commonly known as bread mould.
Answer:
True

4. Spirogyra is marine algae also known as marine silk.
Answer:
False

5. Inside the seed of Pinus gerardiana, almond is present.
Answer:
False

5. Answer in one word:

1. The antherozoids of Selaginella are?
Answer:
Biflagellate

2. Ligule is present in the leaves of?
Answer:
Selaginella

3. Peristome is found in the capsule of?
Answer:
Pellia

4. The main plant body of Funaria is?
Answer:
Carposporophytic

5. The development of seed habit is started with?
Answer:
Heterospory

Students get through the MP Board Class 11th Biology Important Questions Chapter 21 Neural Control and Coordination which are most likely to be asked in the exam.

MP Board Class 11th Biology Important Questions Chapter 21 Neural Control and Coordination

Neural Control and Coordination Class 11 Important Questions Very Short Answer Type

Question 1.
Write the name, nature, origin and distribution area of that nerve which rotates tongue.
Answer:
Hypoglossal nerve rotates the tongue. It is stimulative in nature and originates from the medulla of brain and goes up to the muscles of tongue.

Question 2.
What would be happened in the absence of acetylcholine from synapse?
Answer:
In synapse, acetylcholine transmits the nerve impulse from the axon of one nerve cell to the dendrite of the other nerve cell. Thus in the absence of acetylcholine from synapse nerve impulses do not pass from one nerve cell to other and thus transmission of nerve impulses is inhibited.

Question 3.
Give one example of reflex action.
Answer:
Withdrawal of hand when it is pricked with a needle.

Question 4.
What are axons?
Answer:
The largest branch (dendrite) of nerve cells is known as axon. It plays an important role in the conduction of informations.

Question 5.
Name the humours found in the eyes and describe their functions?
Answer:
Eye has two types of humours :

1.  Aqueous humour: It is a fluid which is filled in aqueous chamber present between the cornea and lens. It
   protects the lens, iris and conjunctiva from direct light and outer forces.
2. Vitreous humour: It is jelly like liquid which is filled in vitreous chamber present between lens and retina. It provides an specific shape to eye ball and also protects it from adherence.

Question 6.
Describe the functions of the following :
(i) Cerebellum,
(ii) Iris,
(iii) Eustachian tube.
Answer:
(i) Cerebellum: The part of the brain which lies behind and below the cerebrum.
(a) Maintenance of posture and equilbrium of the body.
(b) Maintenance of muscle tone.
(c) It modulates and moderates voluntary movements initiated by cerebellum.
(a) It is the site of pain, touch and temperature.

• It controls voluntary movement of muscles, visual and audio sensation.
• Iris: It controls the amount of light that enters the eyes.
• Eustachian tube: It controls the pressure applied on tympanum (membrane between external and middle ears).

Question 7.
What is synapse?
Answer:
Nerve ending of axon of one neuron are connected with the dendrites of next neuron by specific joint is called as Synapse.

Question 8.
Name five sense organs and give their functions.
Answer:

Question 9.
Give nature of following nerves :
(a) Olfactory,
(b) Vagus,
(c) Auditory,
(d) Mandibular.
Answer:

Question 10.
Why owl cannot see during day time but it can see during night ?
Answer:
Owl cannot see during day time as cones are absent in their retina. But it can be able to see during night because their retina possessing a large number of rods.

Question 11.
(a) Which part of the ear determine pitch of the sound ?
(b) Which is the most developed part of the human brain ?
(c) Which part of the central nervous system functions as master clock ?
Answer:
(a) Internal ear,
(b) Cerebrum,
(c) Brain.

Neural Control and Coordination Class 11 Important Questions Short Answer Type

Question 1.
Give functions of cerebrum of man.
Answer:
Functions of cerebrum :

• Its parietal lobe is the centre of pain, touch and stimuli of temperature.
• Its motor area of frontal lobe regulates movement of voluntary muscles.
• Its premotor area of frontal lobe regulates all the functions regulated by autonomous nervous system.
• Its temporal lobe feels taste and smell.
• Visual area of occipital lobe is responsible for the knowledge of light and dark.
• Hypothalamus regulates hunger, thurst and quantity of urine. It also regulates secretion of anterior lobe of pituitary gland.

Question 2.
Write the names of brain ductules of human beings.
Answer:
Human brain consists of a hollow cavity from which the cavity of forebrain is called as lateral cavity. It represents first and second cavity. The cavity of diencephalon is called as third or tertiary cavity. The cavity of mid-brain is called as oieter whereas the cavity of hind-brain is known to be as fourth cavity.

Question 3.
Name the smallest bone of human ear. What happen if this bone is removed ?
Answer:
The smallest bone of human ear is stapes. This bone transmits sound vibration from the tympanic membrane to the membrane of the oval window. This bone increases the force of vibration thus acting like lever, when stapes is removed from ear the waves of sound do not enter the inner ear because stapes which is associated with fenestra ovalis, transmits the vibration of sound into perilymph of vestibular cavity.

Question 4.
What are adrenalin and acetylcholine? Give their functions.
Answer:
Adrenalin and acetylcholine are chemical substances secreted by sympathetic and parasympathetic nerve fibre. Both the chemicals function in opposite way. Adrenalin induces various activities and acetylcholine inhibits them.

Question 5.
What is mosaic vision?
Answer:
This type of vision is found in cockroach because they have compound eyes. Many small images are formed by them. Complete vision is compound form of these many small images and is called as mosaic vision.

Question 6.
Draw a well labelled diagram of longitudinal section of human eye.
Answer:

Question 7.
What is hypermetropia and myopia? (M.P. 1995 Set II)
Answer:
Hypermetropia (Far or Long-sightedness): It is a disease of eyes in which light rays strike the retina before being converged to form image i. e. image is formed beyond the retina. This happens because of (i) abnormally small eye ball, (ii) flattening or abnormally low convexity of the lens. Hypermetropia is corrected by using spectacles with suitable biconvex or convergent lenses.

Myopia (Short sightedness) : This defect results from abnormally long eye ball or abnormally high convexity of lens. The eyes are able to observe nearby objects clearly. However distant objects like writing on the black board or a bird sitting on a tree are not visible properly. It is because of the light rays from distant objects do not form the images on the retina but in front of it in the vitreous humour. The defect is corrected by using spectacles having suitable concave or divergent lens.

Question 8.
What do you understand by nervous system? Nervous system is divided into how many parts?
Answer:
The system which recieves the stimulus, transmits it to the other part of the body and the corresponding effects are shown is known as nervous system.
Nervous system consist of the following three parts :

1. Central nervous system : Comprising of brain and spinal cord.
2. Peripheral nervous system : Includes the nerves which arise from CNS.
3. Autoinomic nervous system : Has connections with central nervous system, but works somewhat independly to regulate the involuntary activites of the body e.g. Heart beat, peristalsis etc.

Question 9.
Explain the role of rods, cones and yellow spot in human eye. (MP 2000, 02, 06 Set C,)
Answer:
1. Rods : Rods are dark light receptors containing rhodopsin synthesized from vitamin A.
Rods are responsible for photopic vision and function best at night and dim light.

2. Cones: Cones are colour receptors containing iodopsin. They function in strong light and responsible for scotopic vision (colour vision).

3.Yellow spot: Posterior part of retina contains only cones and rods are absent and contains yellow pigment called yellow spot. It helps in the formation of clear picture of object.

Question 10.
How many types of nerves are there on the basis of their functions?
Answer:
According to the functions neurons are divided into three parts :

1. Sensory Nerves: These nerve fibers conduct impulses from receptor organ (such as nervous) towards the central nervous system.
2. Motor nerves : These nerve fibres carry the impulses from CNS to effector organs.
3. Mixed nerves: These nerves contain both sensory and motor nerve fibres, hence they do both the functions.

Question 11.
Differentiate the following : (NCERT)
(a) Central Nervous system and peripheral Nervous system.
(b) Resting Potential and Active potential.
(c) Choroid and Retina.
Answer:
(a) Central Nervous System (CNS): Originates from ectoderm part of the embryo. It consists of Brain and spinal cord. Neural tube part of the embryo develops to form this system. This part is responsible for processing of information, where as Peripheral Nervous system (PNS) includes the nerves which arise from the central nervous system.

Nerves arises from brain are called as Cranial nerves and nerves arises from spinal cord are called as spinal nerves. It fonns a communicating system by connecting central nervous system with sensory organs (receptors) through sensory nerves and effector organs through motor nerves.

(b) Resting Potential and Action Potential: At resting stage difference between electric potential of plasma membrane is called as Resting potential. Its value is -70mv, whereas whenever any part of the axon is stimulated depolarisation of Axolemma occurs, thus potential difference decreases up to 30 mV. This is called as Action potential.

(c) Choroid and Retina : Choroid is the middle or second coat of the wall of the eye made up of connective tissue, which is highly vascularised and pigmented. In the front side it fonns iris which has a hole in the centre called as pupil, where as Retina is the innennost layer of the eye wall, which consists of light sensitive cells called as rods (which perceives light) and cones (which distinguish colours).

Question 12.
Explain the structure and functions of spinal cord with diagram.
Or,
Draw a well labelled diagram of T. S. of spinal cord.
Answer:

Structure of spinal cord: The spinal cord consists of central canal surrounded by a central core of grey matter, which is surrounded by white matter. In transverse section, grey matter shows a butterfly shape, i. e., it is produced into two dorsal horns and two ventral horns. A central canal is present in the centre of the grey matter. The spinal cord serves as a centre for spinal reflexes and as pathways to and’from the brain.

The grey matter contains the bodies of neurons with tree-like branching of their dendrons and neurological cells. The white matter is composed of obliquely running medullated nerve fibers supported by pro¬longations of the neuroglia. The bands of fibers which extend transversely, one dorsal and other ventral, to the central canal are known as dorsal and ventral commissures, respectively, Thirty one pairs of spinal nerves arise from the spinal cord. Each nerve is attached to the spinal cord by dorsal and ventral root.

The sensory nerve fibres enter the spinal cord by way of dorsal root while the motor fibres emerge from the spinal cord by way of the ventral root to conduct motor impulses through spinal nerves to effector organs (gland and muscles).
Functions of spinal cord :
(i) Spinal cord controls and coordinates the reflex actions.
(ii) It acts as link between spinal nerves and brain and conducts the impulses of brain.

Question 13.
Write differences between :
(a) Yellow spot and Blindspot.
(b) Short sight and Long sight.
(c) Endolymph and Perilymph.
Answer:
(a) Differences between Yellow spot and Blind spot

(b) Differences between Short sight and Long sight

(c) Differences between Endolymph and Perilymph

Neural Control and Coordination Class 11 Important Questions Long Answer Type

Question 1.
Describe following processes : (NCERT)
(a) Polarisation of membrane of nerve fibre.
(b) Depolarisation of membrane of nerve fibre.
(c) Conduction of impulse through nerve fibre.
(d) Transmission of impulse across synapse (chemically).
Or,
What is nerve impulse? How is it conducted?
Answer:
Nerve impulse: The sum total of the physical and chemical reactions which take place in the propagation of the wave of physiological activity along the nerve fibre is called as nerve impulse.

Propagation of Nerve impulse :

1. Depolarization: When a stimulus of any kind electrical, mechanical or chemical acts on the nerve fibre momentarily, a local increase occurs in the permeability of membrane by opening sodium gate at the site of stimulus. This suddenly brings sodium ions influx into the cell, carrying enough positive charges to the inside to cause complete disappearance of the normal resting potential and usually enough charges to develop a positive state inside the fibre. This positive state of the fibre is called reverse potential. It results in the depolarization of the membrane.

2. Action potential: The changed electrical potential of the plasma membrane of neuron is called action potential. The initial change produces an ionic imbalance across the membrane on either side of the points of stimulus producing local electrical current. These areas of negative depolarization in turn initiate changes in the membrane adjacent to them. A wave of electric charges or depolarization along the length of the nerve fibre or axon is called nerve impulse.

3. Repolarization: With the increase of positive charge inside further entry of Na⁺ is prevented and the permeability of membrane decreases. Na⁺ ions are pushed out which transfer large number of positive charge outside, once again creating negativity inside the membrane which restores the original resting potential. This is known as repolarization. The repolarization starts exactly on the same spot where depolarization had started and then continues to advance ahead. The entire process of repolarization requires some time during which the nerve cannot be stimulated again. It is known as refractory period.

Theories of nerve impulse conduction or Transmission :

1. Saltatory conduction or through nerve fibre : Myelin sheath acts as insulator in the medullated nerve fibres. It is almost impermeable to the ions. The membrane at the nodes of Ranvier is 500 times more permeable. The nerve impulse in these fibres passes from node to node along the entire length of nerve fibre rather than continuously along the entire fibre as occurs in unmyelinated fibre.

This process is called saltatory conduction. It is of dual value. First by causing the depolarization process to jump along nodes of Ranvier on the axis of the nerve fibre increases greatly the speed of impulse travel and secondly saltatory conduction conserves energy for the axon because only the nodes depolarize.
The velocity of conduction in nerve fibre varies from 5 metres per second in a small unmyelinated fibres to as high as 130 metres per second in large myelinated fibres.

Transmission of impulse across synapse (synaptic transmission): The area where the dendrite of one neuron is in close proximity with the axon of another is known as the synapse. The space between the axon and dendrite is called the synaptic cleft.

When the impulse reaches the tip of axon it stimulates the synaptic vehicles which move towards the synaptic cleft and discharge the neurotransmitter or neurohormones.
They then return the knob and become recharged. This chemical neurotransmitter substance has been identified as acetylcholine. Once released the neurotransmitter diffuses across the synaptic cleft and becomes attached to chemo- receptors present on the dendrites of the next neuron.

This attachment triggers the depolarization of the membrane and initiates action potential which travels across the next neuron. Thus, the actual transmission of the impulse across the synapse is by means of specific chemicals. Just after the transmission of impulse through the synapse, acetylcholine is hydrolyzed into acetic-acid and choline by the enzyme acetylcholinesterase present in the post synaptic membrane. The membrane again becomes polarized, so another impulse must come down the axon and release more acetylcholine for the transmission of another impulse.

Question 2.
Give three-three functions of sympathetic and parasympathetic nervous system.
Answer:
Functions of Sympathetic Nervous System :

1. Sympathetic nervous system maintains the physical balance during distress conditions.
2. It stimulates the adrenal glands to secrete adrenalin. Thus, sympathetic nerves function with the adrenal glands as a well-integrated sympathetic-adrenal system having widespread effects.
3. This system is responsible for the increase in the rate of heartbeat and blood pressure.
4. It reduces the peristaltic movement of alimentary canal.
5. It brings about the extension of pupil.
6. It contracts the sphincter muscles of urinary bladder.
7. It increases the sugar level in blood.
8. It increases the number of RBCs in blood.

Functions of Parasympathetic Nervous System :

• Parasympathetic nervous system opposes the effects of the sympathetic autonomic system.
• It decreases rate of heartbeat.
• It decreases blood pressure.
• The nerve ending of this system secrete acetylcholine.
• It constricts pupil of the eyes.
• It relaxes the muscles of root hairs.
• It contracts the muscles of ureter.
• It increases the secretion of saliva and digestive juices.

Question 3.
Name the regulating centre of following in brain :
(a) Temperature,
(b) Hunger,
(c) Respiration,
(d) Water balance,
(e) Vision,
(f) Hearing,
(g) Menstrual cycle,
(h) Learning, (i) Pituitary gland,
(j) Coordination and equilibrium,
(k) Transport,
(l) Sleep,
(m) Heartbeat.
Answer:
(a) Temperature – Thalamus
(b) Hunger – Hypothalamus
(c) Respiration – Medulla oblongata
(d) Water balance – Hypothalamus
(e) Vision – Cerebral cortex
(f) Hearing – Cerebral cortex
(g) Menstrual cycle – Hypothalamus
(h) Learning – Cerebral cortex
(i) Pituitary gland – Hypothalamus
(j) Equilibrium and Coordination – Cerebellum
(k) Transport – Medulla oblongata
(l) Sleep – Cerebral cortex
(m) Heartbeat – Medulla oblongata.

Question 4.
Describe following structures in breif. (NCERT)
(A) Brain,
(B) Eye,
(C) Ear.
Answer:
(A) Brain: Mammalian brain is divisible into three parts :
1. Fore-brain or prosencephalon consists of cerebrum (telencephalon), olfactory lobes (rhinencephalon) and diencephalon (thalamencephalon).
2. Mid-brain or mesencephalon consists of optic lobes (corpora quadrigemina) and cerebral peduncle.
3. Hind-brain or rhombencephalon formed of cerebellum (metencephalon), medulla oblongata (myelencephalon) and pons varoli.

(1) Forebrain :

(i) Olfactory lobe : In mammals the olfactory lobes are located at the anterior end of brain, ventral in position. They are reduced and covered by cerebral hemisphere. Each lobe is further differentiated into olfactory bulb and olfactory tract. The olfactory tract ends in a rounded elevation, the tuberculum olfactory. But in human brain due to the over-development of cerebrum the olfactory lobes get incorporated with the cerebrum and are visible only in the ventral view. Olfactory lobes are concerned with the sense of smell. The nature of the nerve arising from the olfactory lobes are purely sensory.

(ii) Cerebrum: Cerebrum is the largest part of the brain. It is made up of two halves, the right and the left cerebral hemispheres. A deep median longitudinal groove is the demarkation between two halves. The two halves are connected by means of a broad transverse band of white matter called corpus callosum or cerebri.

Deep furrows divide each cerebral hemisphere into frontal lobe, temporal lobe, occipital lobe and a small lobe called insula. Insula is a triangular eminence lying deeply in lateral fissure of temporal lobe. The other lobes are named according to the position they occupy. The surface of cerebrum is folded, having elevation and depressions called sulci and gyri that increases surface area.

(iii) Diencephalon: It is a small area, it remains covered with cerebrum. It consists of following:
(a) Epithalamus: It forms the roof of diencephalon having anterior choroid plexus concerned with supply of nutrition of brain and vestigial pineal body.

(b) Optic thalami: These forms lateral walls of diencephalon and contain optic fibres which go towards cerebrum.
(iv) Hypothalamus : The base of the brain constitutes the hypothalamus. It forms the floor of diencephalon. It has a hypophysis or master gland or pituitary gland, which is an endocrine gland. Anterior to it is a geniculate body which relay optic impulses to cerebrum. An optic chiasma is formed by the crossing of optic fibres. The hypothalamus, consists of large amount of grey matter present within the white matter. It contains the nerve centres for control of temperature, hunger, thirst and emotions, sleep and sexual activities. It also produces various neurohormones that control the secretion of anterior pituitary. Hormones of posterior pituitary are produced in hypothalamus which reach the pituitary by hypophyseal portal vessels.

2. Mid-brain: The mid-brain or mesencephalon joins the cerebrum with the cerebellum. It consists of four lobes called quadrigemina. Anterior pair of lobes is concerned with vision and posterior ones with hearing. It has large number of nerve cells scattered within the white matter. These nerve cells are involved in controlling the voluntary muscle activities and also act as centres for auditory and visual reflexes. It can modify some motor activities initiated by cortex.

3. Hind-brain: The hind brain or rhombencephalon consists of cerebellum, pons and medulla and many visceral functions forms its major part and is a large reflex centre for the co-ordination of activities of voluntary muscles.
The brain-stem consists of pons varoli in front of cerebellum and behind it medulla oblongata is present. Pons varoli runs transversely and carries impulses from one portion of cerebellum to another. The medulla oblongata lies in between the pons varoli and spinal cord and controls various reflexes like breathing, swallowing, salivation, chewing, coughing, sneezing etc.

(B) Human Eye: L.S. of human eye : Human eye is a spherical ball like structure filled with a vitreous liquid. It is covered by upper and lower eyelids. The eyeball of human beings is made up of from the following three layers :

1. Sclerotic layer: It is the outermost layer of eye. Their 1/3 transparent part is called as cornea. Covering of cornea is a thin transparent membrane called conjunctiva. Cornea permits light to enter the eye.

2. Choroid layer: It is an extensive plexus of small blood vessels embedded in loose connective tissue. At the anterior margin of the choroid a greatly thickened structure projects immediately into the eyeball towards the margin of the lens.

This portion of the choroid is called as ciliary body. Anterior to the ciliary body the vascular tunic is thin and constitute the iris of the eye; in the middle of the iris is a round opening called the pupil. A lens (biconcave) is present below the iris which is encased in a strong fibrous lens capsule and containing a high concentration of protein.

3. Retina: It is the innermost part of the eye which lines the inside surface of the posterior two third of the eyeball and lies on the inner surface of the choroid. The retina containing light sensitive cells called rods and cones that detect light and colour and then send appropriate signals to the brain to cause vision.
Two functions of rods and cones are :

1. The photoreceptor, rod cells of retina contain rhodopsin. They function in dim light and enable us to see in darkness at night.
2. The photoreceptor, cone cells of retina contain iodopsin. They function in day light and artificial bright light. They are associated with perception of colours

Note: For

(C) Ear: Human ear is highly developed. It can be divided into three parts :

1. External ear: It consists of flap like structure called pinna which collects sound and pass it to the auditory canal, at the end of which tympanic membrane is found.

2. Middle ear: It consists of tympanic cavity which is present between the tympanic membrane and the internal ear. Three small bones called ear ossicles are found in the middle ear. The first bone, which is club-shaped and is attached at one end to the tympanic membrane is called malleus.
Its other end is attached to an anvil-shaped bone called incus. The narrow end of incus is attached to the bone called stapes which is stirrup-shaped and has an aperture in it.

The other end of stapes is fixed to the membrane on the fenestra ovalis. In mammals, all these three bones originate from the bones of the jaws, malleus from articular, incus from quadrate and stapes from hyomandibular. The tympanic cavity is connected with the pharynx by means of eustachian tube.

3. Internal ear: The membranou s labyrinth of internal ear consists of two chambers : utriculus and sacculus. These chambers are connected with each other by a narrow canal called saccularicular canal. Three semicircular canals arise from the utriculus. According to their position, they are known as anterior, posterior and external or horizontal semicircular canals. The anterior and posterior semicircular canals arise together and run for a short distance and then separate. After taking a curved course, their other ends again open into the utriculus where each of them enlarges to form an ampulla. Each ampulla contains a sensory crista which is formed of ciliated and supporting cells.

Two such cristae maculae are present in sacculus and one in the utriculus. The hind part of sacculus is coiled like a spring and is known as cochlear duct. Utriculus, ampullae, semicircular canals, sacculus and cochlear duct are all filled with a thick fluid called endolymph which contains minute particles of calcium carbonate known
as otoliths.

The internal ear is situated in the temporal region of the skull within the periotic bones which take the shape of the internal ear. Thus the whole internal ear, i.e., membranous labyrinth is enclosed in a bony labyrinth.
The space between these two is filled with a fluid called perilymph. The cochlea is associated with hearing. It is a bony tube coiled like a conch shell. It is wound around a bony cone of bone, known as central pillar or modiolus. The cochlear nerve passes through the modiolus. The scala media remains separated from the vestibular canal of the bony labyrinth by a vestibular membrane or resisters membrane. It is also separated from the underlying tympanic canal by a basilar membrane.

The basilar membrane possesses several rows of hair cells serving as auditory receptors all along its coiled course. This structure is known as Organ of Corti which is the organ of hearing. It is composed of several specialized cells. Corti’s rods are double row of arching rods based on basilar membrane and ‘forming the spiral tunnel of Corti. Hair cells are the sensory organ of Corti’s organ. Dieters cells are the supporting cells between rows of outer hair cells in organ of Corti. A tectorial membrane lies in contact with the hair cells.

Question 5.
Draw labelled diagrams of following :
(a) Neuron,
(b) Brain,
(c) Eye,
(d) Ear. (NCERT)
Answer:
(a) Neuron :

(b) Brain:

(A) Brain: Mammalian brain is divisible into three parts :
1. Fore-brain or prosencephalon consists of cerebrum (telencephalon), olfactory lobes (rhinencephalon) and diencephalon (thalamencephalon).
2. Mid-brain or mesencephalon consists of optic lobes (corpora quadrigemina) and cerebral peduncle.
3. Hind-brain or rhombencephalon formed of cerebellum (metencephalon), medulla oblongata (myelencephalon) and pons varoli.

(1) Forebrain :

(i) Olfactory lobe : In mammals the olfactory lobes are located at the anterior end of brain, ventral in position. They are reduced and covered by cerebral hemisphere. Each lobe is further differentiated into olfactory bulb and olfactory tract. The olfactory tract ends in a rounded elevation, the tuberculum olfactorium. But in human brain due to the over development of cerebrum the olfactory lobes get incorporated with the cerebrum and are visible only in the ventral view. Olfactory lobes are concerned with the sense of smell. The nature of the nerve arising from the olfactory lobes are purely sensory.

(ii) Cerebrum: Cerebrum is the largest part of the brain. It is made up of two halves, the right and the left cerebral hemispheres. A deep median longitudinal groove is the demarkation between two halves. The two halves are connected by means of a broad transverse band of white matter called corpus callosum or cerebri.

Deep furrows divide each cerebral hemisphere into frontal lobe, temporal lobe, occipital lobe and a small lobe called insula. Insula is a triangular eminence lying deeply in lateral fissure of temporal lobe. The other lobes are named according to the position they occupy. The surface of cerebrum is folded, having elevation and depressions called sulci and gyri that increases surface area.

(iii) Diencephalon: It is a small area, it remains covered with cerebrum. It consists of following:
(a) Epithalamus: It forms the roof of diencephalon having anterior choroid plexus concerned with supply of nutrition of brain and vestigial pineal body.

(b) Optic thalami: These forms lateral walls of diencephalon and contain optic fibres which go towards cerebrum.
(iv) Hypothalamus : The base of the brain constitutes the hypothalamus. It forms the floor of diencephalon. It has a hypophysis or master gland or pituitary gland, which is an endocrine gland. Anterior to it is a geniculate body which relay optic impulses to cerebrum.

An optic chiasma is formed by the crossing of optic fibres. The hypothalamus, consists of large amount of grey matter present within the white matter. It contains the nerve centres for control of temperature, hunger, thirst and emotions, sleep and sexual activities. It also produces various neurohormones that control the secretion of anterior pituitary. Hormones of posterior pituitary are produced in hypothalamus which reach the pituitary by hypophyseal portal vessels.

2. Mid-brain: The mid-brain or mesencephalon joins the cerebrum with the cerebellum. It consists of four lobes called quadrigeminal. Anterior pair of lobes is concerned with vision and posterior ones with hearing. It has large number of nerve cells scattered within the white matter. These nerve cells are involved in controlling the voluntary muscle activities and also act as centres for auditory and visual reflexes. It can modify some motor activities initiated by cortex.

3. Hind-brain: The hind brain or rhombencephalon consists of cerebellum, pons and medulla and many visceral functions forms its major part and is a large reflex centre for the co-ordination of activities of voluntary muscles.

The brain-stem consists of pons varoli in front of cerebellum and behind it medulla oblongata is present. Pons varoli runs transversely and carries impulses from one portion of cerebellum to another. The medulla oblongata lies in between the pons varoli and spinal cord and controls various reflexes like breathing, swallowing, salivation, chewing, coughing, sneezing etc.

(C) Ear:

Human ear is highly developed. It can be divided into three parts :

1. External ear: It consists of flap like structure called pinna which collects sound and pass it to the auditory canal, at the end of which tympanic membrane is found.

2. Middle ear: It consists of tympanic cavity which is present between the tympanic membrane and the internal ear. Three small bones called ear ossicles are found in the middle ear. The first bone, which is club-shaped and is attached at one end to the tympanic membrane is called malleus.
Its other end is attached to an anvil-shaped bone called incus. The narrow end of incus is attached to the bone called stapes which is stirrup-shaped and has an aperture in it.

The other end of stapes is fixed to the membrane on the fenestra ovalis. In mammals, all these three bones originate from the bones of the jaws, malleus from articular, incus from quadrate and stapes from hyomandibular. The tympanic cavity is connected with the pharynx by means of eustachian tube.

3. Internal ear: The membranou s labyrinth of internal ear consists of two chambers : utriculus and sacculus. These chambers are connected with each other by a narrow canal called saccularicular canal. Three semicircular canals arise from the utriculus. According to their position, they are known as anterior, posterior and external or horizontal semicircular canals. The anterior and posterior semicircular canals arise together and run for a short distance and then separate. After taking a curved course, their other ends again open into the utriculus where each of them enlarges to form an ampulla. Each ampulla contains a sensory crista which is formed of ciliated and supporting cells.

Two such cristae maculae are present in sacculus and one in the utriculus. The hind part of sacculus is coiled like a spring and is known as cochlear duct. Utriculus, ampullae, semicircular canals, sacculus and cochlear duct are all filled with a thick fluid called endolymph which contains minute particles of calcium carbonate known
as otoliths.

The internal ear is situated in the temporal region of the skull within the periotic bones which take the shape of the internal ear. Thus the whole internal ear, i.e., membranous labyrinth is enclosed in a bony labyrinth.
The space between these two is filled with a fluid called perilymph. The cochlea is associated with hearing. It is a bony tube coiled like a conch shell. It is wound around a bony cone of bone, known as central pillar or modiolus. The cochlear nerve passes through the modiolus. The scala media remains separated from the vestibular canal of the bony labyrinth by a vestibular membrane or reissners membrane. It is also separated from the underlying tympanic canal by a basilar membrane.

The basilar membrane possesses several rows of hair cells serving as auditory receptors all along its coiled course. This structure is known as Organ of Corti which is the organ of hearing. It is composed of several specialized cells. Corti’s rods are double row of arching rods based on basilar membrane and ‘forming the spiral tunnel of Corti. Hair cells are the sensory organ of Corti’s organ. Dieters cells are the supporting cells between rows of outer hair cells in organ of Corti. A tectorial membrane lies in contact with the hair cells.

(c) Eye :

Note: For

(d) Ear :

Human ear is highly developed. It can be divided into three parts :

1. External ear: It consists of flap like structure called pinna which collects sound and pass it to the auditory canal, at the end of which tympanic membrane is found.

2. Middle ear: It consists of tympanic cavity which is present between the tympanic membrane and the internal ear. Three small bones called ear ossicles are found in the middle ear. The first bone, which is club-shaped and is attached at one end to the tympanic membrane is called malleus.
Its other end is attached to an anvil-shaped bone called incus. The narrow end of incus is attached to the bone called stapes which is stirrup-shaped and has an aperture in it.

The other end of stapes is fixed to the membrane on the fenestra ovalis. In mammals, all these three bones originate from the bones of the jaws, malleus from articular, incus from quadrate and stapes from hyomandibular. The tympanic cavity is connected with the pharynx by means of eustachian tube.

3. Internal ear: The membranou s labyrinth of internal ear consists of two chambers : utriculus and sacculus. These chambers are connected with each other by a narrow canal called saccularicular canal. Three semicircular canals arise from the utriculus. According to their position, they are known as anterior, posterior and external or horizontal semicircular canals. The anterior and posterior semicircular canals arise together and run for a short distance and then separate. After taking a curved course, their other ends again open into the utriculus where each of them enlarges to form an ampulla. Each ampulla contains a sensory crista which is formed of ciliated and supporting cells.

Two such cristae maculae are present in sacculus and one in the utriculus. The hind part of sacculus is coiled like a spring and is known as cochlear duct. Utriculus, ampullae, semicircular canals, sacculus and cochlear duct are all filled with a thick fluid called endolymph which contains minute particles of calcium carbonate known
as otoliths.

The internal ear is situated in the temporal region of the skull within the periotic bones which take the shape of the internal ear. Thus the whole internal ear, i.e., membranous labyrinth is enclosed in a bony labyrinth.
The space between these two is filled with a fluid called perilymph. The cochlea is associated with hearing. It is a bony tube coiled like a conch shell. It is wound around a bony cone of bone, known as central pillar or modiolus. The cochlear nerve passes through the modiolus. The scala media remains separated from the vestibular canal of the bony labyrinth by a vestibular membrane or reissners membrane. It is also separated from the underlying tympanic canal by a basilar membrane.

The basilar membrane possesses several rows of hair cells serving as auditory receptors all along its coiled course. This structure is known as Organ of Corti which is the organ of hearing. It is composed of several specialized cells. Corti’s rods are double row of arching rods based on basilar membrane and ‘forming the spiral tunnel of Corti. Hair cells are the sensory organ of Corti’s organ. Dieters cells are the supporting cells between rows of outer hair cells in organ of Corti. A tectorial membrane lies in contact with the hair cells.

Question 6.
Write short notes on following : (NCERT)
(a) Mechanism of synaptic conduction.
(b) Mechanism of vision.
(c) Mechanism of hearing.
Answer:
(a) Mechanism of synaptic conduction:
Nerve impulse: The sum total of the physical and chemical reactions which take place in the propagation of the wave of physiological activity along the nerve fibre is called as nerve impulse.

Propagation of Nerve impulse :

1. Depolarization: When a stimulus of any kind electrical, mechanical or chemical acts on the nerve fibre momentarily, a local increase occurs in the permeability of membrane by opening sodium gate at the site of stimulus. This suddenly brings sodium ions influx into the cell, carrying enough positive charges to the inside to cause complete disappearance of the normal resting potential and usually enough charges to develop a positive state inside the fibre. This positive state of the fibre is called reverse potential. It results in the depolarization of the membrane.

2. Action potential: The changed electrical potential of the plasma membrane of neuron is called action potential. The initial change produces an ionic imbalance across the membrane on either side of the points of stimulus producing local electrical current. These areas of negative depolarization in turn initiate changes in the membrane adjacent to them. A wave of electric charges or depolarization along the length of the nerve fibre or axon is called nerve impulse.

3. Repolarization: With the increase of positive charge inside further entry of Na⁺ is prevented and the permeability of membrane decreases. Na⁺ ions are pushed out which transfer large number of positive charge outside, once again creating negativity inside the membrane which restores the original resting potential. This is known as repolarization. The repolarization starts exactly on the same spot where depolarization had started and then continues to advance ahead. The entire process of repolarization requires some time during which the nerve cannot be stimulated again. It is known as refractory period.

Theories of nerve impulse conduction or Transmission :

1. Saltatory conduction or through nerve fibre : Myelin sheath acts as insulator in the medullated nerve fibres. It is almost impermeable to the ions. The membrane at the nodes of Ranvier is 500 times more permeable. The nerve impulse in these fibres passes from node to node along the entire length of nerve fibre rather than continuously along the entire fibre as occurs in unmyelinated fibre.

This process is called saltatory conduction. It is of dual value. First by causing the depolarization process to jump along nodes of Ranvier on the axis of the nerve fibre increases greatly the speed of impulse travel and secondly saltatory conduction conserves energy for the axon because only the nodes depolarize.
The velocity of conduction in nerve fibre varies from 5 metres per second in a small unmyelinated fibres to as high as 130 metres per second in large myelinated fibres.

Transmission of impulse across synapse (synaptic transmission): The area where the dendrite of one neuron is in close proximity with the axon of another is known as the synapse. The space between the axon and dendrite is called the synaptic cleft.

When the impulse reaches the tip of axon it stimulates the synaptic vehicles which move towards the synaptic cleft and discharge the neurotransmitter or neurohormones.
They then return the knob and become recharged. This chemical neurotransmitter substance has been identified as acetylcholine. Once released the neurotransmitter diffuses across the synaptic cleft and becomes attached to chemo- receptors present on the dendrites of the next neuron.

This attachment triggers the depolarization of the membrane and initiates action potential which travels across the next neuron. Thus, the actual transmission of the impulse across the synapse is by means of specific chemicals. Just after the transmission of impulse through the synapse, acetylcholine is hydrolyzed into acetic-acid and choline by the enzyme acetylcholinesterase present in the post synaptic membrane. The membrane again becomes polarized, so another impulse must come down the axon and release more acetylcholine for the transmission of another impulse.

(b) Mechanism of vision: For seeing clear distant object it is essential that image must be focussed on the retina so that photoreceptor rods and cones are stimulated. Rays of light from the object fall on the biconvex lens after passing through the conjunctiva, cornea and pupil. The size of the pupil regulates the amount of light entering the eyeball. Thus, an inverted image of the object is formed on the retina which is conveyed to the brain by the optic nerve. The image is then reinverted by the brain.

The eyes have got the property to form image of both far and near objects on retina by changing the convexity of the lens. This is called power of accommodation.

(c) Mechanism of hearing: The sound waves first strike the pinna which keeps on moving to direct the sound waves into tympanic cavity. These waves then strike the tympanic membrane which starts vibrating due to which the ear ossicles are vibrated.

Thus it is transmitted the membrane over the fenestra ovalis into scala vestibule of the cochlea. In this way, the perilymph filled in it also gets vibrated due to which Reissner’s and basilar membranes start vibrating. By the vibration of these membranes, the endolymph of scala media also vibrates as well as the tectorial membrane.

Because of the vibration of endolymph of scala media, the sensory hairs of the receptor cells of the organ of Corti are stretched and bent due to which the receptor cells gets stimulated and send the impulses to the brain through cochlear nerve. In the manner the sound is heard.

Question 7.
(a) Decribe role of Na⁺ in production of action potential.
(b) Describe role of Ca⁺⁺ in discharge of neurotransmitter at svnapse.
(c) Explain mechanism of production of impulse on the retina by light.
(d) Explain mechanism of production of nerve impulse by sound in the internal ear.
Answer:
(a)

Nerve impulse: The sum total of the physical and chemical reactions which take place in the propagation of the wave of physiological activity along the nerve fibre is called as nerve impulse.
Propagation of Nerve impulse :
1. Depolarization: When a stimulus of any kind electrical, mechanical or chemical acts on the nerve fibre momentarily, a local increase occurs in the permeability of membrane by opening sodium gate at the site of stimulus. This suddenly brings sodium ions influx into the cell, carrying enough positive charges to the inside to cause complete disappearance of the normal resting potential and usually enough charges to develop a positive state inside the fibre. This positive state of the fibre is called reverse potential. It results in the depolarization of the membrane.

2. Action potential: The changed electrical potential of the plasma membrane of neuron is called action potential. The initial change produces an ionic imbalance across the membrane on either side of the points of stimulus producing local electrical current. These areas of negative depolarization in turn initiate changes in the membrane adjacent to them. A wave of electric charges or depolarization along the length of the nerve fibre or axon is called nerve impulse.

3. Repolarization: With the increase of positive charge inside further entry of Na⁺ is prevented and the permeability of membrane decreases. Na⁺ ions are pushed out which transfer large number of positive charge outside, once again creating negativity inside the membrane which restores the original resting potential. This is known as repolarization. The repolarization starts exactly on the same spot where depolarization had started and then continues to advance ahead. The entire process of repolarization requires some time during which the nerve cannot be stimulated again. It is known as refractory period.

Theories of nerve impulse conduction or Transmission :

1. Saltatory conduction or through nerve fibre : Myelin sheath acts as insulator in the medullated nerve fibres. It is almost impermeable to the ions. The membrane at the nodes of Ranvier is 500 times more permeable. The nerve impulse in these fibres passes from node to node along the entire length of nerve fibre rather than continuously along the entire fibre as occurs in unmyelinated fibre.

This process is called saltatory conduction. It is of dual value. First by causing the depolarization process to jump along nodes of Ranvier on the axis of the nerve fibre increases greatly the speed of impulse travel and secondly saltatory conduction conserves energy for the axon because only the nodes depolarize.
The velocity of conduction in nerve fibre varies from 5 metres per second in a small unmyelinated fibres to as high as 130 metres per second in large myelinated fibres.

Transmission of impulse across synapse (synaptic transmission): The area where the dendrite of one neuron is in close proximity with the axon of another is known as the synapse. The space between the axon and dendrite is called the synaptic cleft.

When the impulse reaches the tip of axon it stimulates the synaptic vehicles which move towards the synaptic cleft and discharge the neurotransmitter or neurohormones.
They then return the knob and become recharged. This chemical neurotransmitter substance has been identified as acetylcholine. Once released the neurotransmitter diffuses across the synaptic cleft and becomes attached to chemo- receptors present on the dendrites of the next neuron.

This attachment triggers the depolarization of the membrane and initiates action potential which travels across the next neuron. Thus, the actual transmission of the impulse across the synapse is by means of specific chemicals. Just after the transmission of impulse through the synapse, acetylcholine is hydrolyzed into acetic-acid and choline by the enzyme acetylcholinesterase present in the post synaptic membrane. The membrane again becomes polarized, so another impulse must come down the axon and release more acetylcholine for the transmission of another impulse.

(b)

(a)

Nerve impulse: The sum total of the physical and chemical reactions which take place in the propagation of the wave of physiological activity along the nerve fibre is called as nerve impulse.
Propagation of Nerve impulse :
1. Depolarization: When a stimulus of any kind electrical, mechanical or chemical acts on the nerve fibre momentarily, a local increase occurs in the permeability of membrane by opening sodium gate at the site of stimulus. This suddenly brings sodium ions influx into the cell, carrying enough positive charges to the inside to cause complete disappearance of the normal resting potential and usually enough charges to develop a positive state inside the fibre. This positive state of the fibre is called reverse potential. It results in the depolarization of the membrane.

2. Action potential: The changed electrical potential of the plasma membrane of neuron is called action potential. The initial change produces an ionic imbalance across the membrane on either side of the points of stimulus producing local electrical current. These areas of negative depolarization in turn initiate changes in the membrane adjacent to them. A wave of electric charges or depolarization along the length of the nerve fibre or axon is called nerve impulse.

3. Repolarization: With the increase of positive charge inside further entry of Na⁺ is prevented and the permeability of membrane decreases. Na⁺ ions are pushed out which transfer large number of positive charge outside, once again creating negativity inside the membrane which restores the original resting potential. This is known as repolarization. The repolarization starts exactly on the same spot where depolarization had started and then continues to advance ahead. The entire process of repolarization requires some time during which the nerve cannot be stimulated again. It is known as refractory period.

Theories of nerve impulse conduction or Transmission :

1. Saltatory conduction or through nerve fibre : Myelin sheath acts as insulator in the medullated nerve fibres. It is almost impermeable to the ions. The membrane at the nodes of Ranvier is 500 times more permeable. The nerve impulse in these fibres passes from node to node along the entire length of nerve fibre rather than continuously along the entire fibre as occurs in unmyelinated fibre.

This process is called saltatory conduction. It is of dual value. First by causing the depolarization process to jump along nodes of Ranvier on the axis of the nerve fibre increases greatly the speed of impulse travel and secondly saltatory conduction conserves energy for the axon because only the nodes depolarize.
The velocity of conduction in nerve fibre varies from 5 metres per second in a small unmyelinated fibres to as high as 130 metres per second in large myelinated fibres.

Transmission of impulse across synapse (synaptic transmission): The area where the dendrite of one neuron is in close proximity with the axon of another is known as the synapse. The space between the axon and dendrite is called the synaptic cleft.

When the impulse reaches the tip of axon it stimulates the synaptic vehicles which move towards the synaptic cleft and discharge the neurotransmitter or neurohormones.
They then return the knob and become recharged. This chemical neurotransmitter substance has been identified as acetylcholine. Once released the neurotransmitter diffuses across the synaptic cleft and becomes attached to chemo- receptors present on the dendrites of the next neuron.

This attachment triggers the depolarization of the membrane and initiates action potential which travels across the next neuron. Thus, the actual transmission of the impulse across the synapse is by means of specific chemicals. Just after the transmission of impulse through the synapse, acetylcholine is hydrolyzed into acetic-acid and choline by the enzyme acetylcholinesterase present in the post synaptic membrane. The membrane again becomes polarized, so another impulse must come down the axon and release more acetylcholine for the transmission of another impulse.

(c)

(a) Mechanism of synaptic conduction:
Nerve impulse: The sum total of the physical and chemical reactions which take place in the propagation of the wave of physiological activity along the nerve fibre is called as nerve impulse.

Propagation of Nerve impulse :

1. Depolarization: When a stimulus of any kind electrical, mechanical or chemical acts on the nerve fibre momentarily, a local increase occurs in the permeability of membrane by opening sodium gate at the site of stimulus. This suddenly brings sodium ions influx into the cell, carrying enough positive charges to the inside to cause complete disappearance of the normal resting potential and usually enough charges to develop a positive state inside the fibre. This positive state of the fibre is called reverse potential. It results in the depolarization of the membrane.

2. Action potential: The changed electrical potential of the plasma membrane of neuron is called action potential. The initial change produces an ionic imbalance across the membrane on either side of the points of stimulus producing local electrical current. These areas of negative depolarization in turn initiate changes in the membrane adjacent to them. A wave of electric charges or depolarization along the length of the nerve fibre or axon is called nerve impulse.

3. Repolarization: With the increase of positive charge inside further entry of Na⁺ is prevented and the permeability of membrane decreases. Na⁺ ions are pushed out which transfer large number of positive charge outside, once again creating negativity inside the membrane which restores the original resting potential. This is known as repolarization. The repolarization starts exactly on the same spot where depolarization had started and then continues to advance ahead. The entire process of repolarization requires some time during which the nerve cannot be stimulated again. It is known as refractory period.

Theories of nerve impulse conduction or Transmission :

1. Saltatory conduction or through nerve fibre : Myelin sheath acts as insulator in the medullated nerve fibres. It is almost impermeable to the ions. The membrane at the nodes of Ranvier is 500 times more permeable. The nerve impulse in these fibres passes from node to node along the entire length of nerve fibre rather than continuously along the entire fibre as occurs in unmyelinated fibre.

This process is called saltatory conduction. It is of dual value. First by causing the depolarization process to jump along nodes of Ranvier on the axis of the nerve fibre increases greatly the speed of impulse travel and secondly saltatory conduction conserves energy for the axon because only the nodes depolarize.
The velocity of conduction in nerve fibre varies from 5 metres per second in a small unmyelinated fibres to as high as 130 metres per second in large myelinated fibres.

Transmission of impulse across synapse (synaptic transmission): The area where the dendrite of one neuron is in close proximity with the axon of another is known as the synapse. The space between the axon and dendrite is called the synaptic cleft.

When the impulse reaches the tip of axon it stimulates the synaptic vehicles which move towards the synaptic cleft and discharge the neurotransmitter or neurohormones.
They then return the knob and become recharged. This chemical neurotransmitter substance has been identified as acetylcholine. Once released the neurotransmitter diffuses across the synaptic cleft and becomes attached to chemo- receptors present on the dendrites of the next neuron.

This attachment triggers the depolarization of the membrane and initiates action potential which travels across the next neuron. Thus, the actual transmission of the impulse across the synapse is by means of specific chemicals. Just after the transmission of impulse through the synapse, acetylcholine is hydrolyzed into acetic-acid and choline by the enzyme acetylcholinesterase present in the post synaptic membrane. The membrane again becomes polarized, so another impulse must come down the axon and release more acetylcholine for the transmission of another impulse.

(b) Mechanism of vision: For seeing clear distant object it is essential that image must be focussed on the retina so that photoreceptor rods and cones are stimulated. Rays of light from the object fall on the biconvex lens after passing through the conjunctiva, cornea and pupil. The size of the pupil regulates the amount of light entering the eyeball. Thus, an inverted image of the object is formed on the retina which is conveyed to the brain by the optic nerve. The image is then reinverted by the brain.

The eyes have got the property to form image of both far and near objects on retina by changing the convexity of the lens. This is called power of accommodation.

(c) Mechanism of hearing: The sound waves first strike the pinna which keeps on moving to direct the sound waves into tympanic cavity. These waves then strike the tympanic membrane which starts vibrating due to which the ear ossicles are vibrated.

Thus it is transmitted the membrane over the fenestra ovalis into scala vestibule of the cochlea. In this way, the perilymph filled in it also gets vibrated due to which Reissner’s and basilar membranes start vibrating. By the vibration of these membranes, the endolymph of scala media also vibrates as well as the tectorial membrane.

Because of the vibration of endolymph of scala media, the sensory hairs of the receptor cells of the organ of Corti are stretched and bent due to which the receptor cells gets stimulated and send the impulses to the brain through cochlear nerve. In the manner the sound is heard.

(d)

(a) Mechanism of synaptic conduction:
Nerve impulse: The sum total of the physical and chemical reactions which take place in the propagation of the wave of physiological activity along the nerve fibre is called as nerve impulse.

Propagation of Nerve impulse :

1. Depolarization: When a stimulus of any kind electrical, mechanical or chemical acts on the nerve fibre momentarily, a local increase occurs in the permeability of membrane by opening sodium gate at the site of stimulus. This suddenly brings sodium ions influx into the cell, carrying enough positive charges to the inside to cause complete disappearance of the normal resting potential and usually enough charges to develop a positive state inside the fibre. This positive state of the fibre is called reverse potential. It results in the depolarization of the membrane.

2. Action potential: The changed electrical potential of the plasma membrane of neuron is called action potential. The initial change produces an ionic imbalance across the membrane on either side of the points of stimulus producing local electrical current. These areas of negative depolarization in turn initiate changes in the membrane adjacent to them. A wave of electric charges or depolarization along the length of the nerve fibre or axon is called nerve impulse.

3. Repolarization: With the increase of positive charge inside further entry of Na⁺ is prevented and the permeability of membrane decreases. Na⁺ ions are pushed out which transfer large number of positive charge outside, once again creating negativity inside the membrane which restores the original resting potential. This is known as repolarization. The repolarization starts exactly on the same spot where depolarization had started and then continues to advance ahead. The entire process of repolarization requires some time during which the nerve cannot be stimulated again. It is known as refractory period.

Theories of nerve impulse conduction or Transmission :

1. Saltatory conduction or through nerve fibre : Myelin sheath acts as insulator in the medullated nerve fibres. It is almost impermeable to the ions. The membrane at the nodes of Ranvier is 500 times more permeable. The nerve impulse in these fibres passes from node to node along the entire length of nerve fibre rather than continuously along the entire fibre as occurs in unmyelinated fibre.

This process is called saltatory conduction. It is of dual value. First by causing the depolarization process to jump along nodes of Ranvier on the axis of the nerve fibre increases greatly the speed of impulse travel and secondly saltatory conduction conserves energy for the axon because only the nodes depolarize.
The velocity of conduction in nerve fibre varies from 5 metres per second in a small unmyelinated fibres to as high as 130 metres per second in large myelinated fibres.

Transmission of impulse across synapse (synaptic transmission): The area where the dendrite of one neuron is in close proximity with the axon of another is known as the synapse. The space between the axon and dendrite is called the synaptic cleft.

When the impulse reaches the tip of axon it stimulates the synaptic vehicles which move towards the synaptic cleft and discharge the neurotransmitter or neurohormones.
They then return the knob and become recharged. This chemical neurotransmitter substance has been identified as acetylcholine. Once released the neurotransmitter diffuses across the synaptic cleft and becomes attached to chemo- receptors present on the dendrites of the next neuron.

This attachment triggers the depolarization of the membrane and initiates action potential which travels across the next neuron. Thus, the actual transmission of the impulse across the synapse is by means of specific chemicals. Just after the transmission of impulse through the synapse, acetylcholine is hydrolyzed into acetic-acid and choline by the enzyme acetylcholinesterase present in the post synaptic membrane. The membrane again becomes polarized, so another impulse must come down the axon and release more acetylcholine for the transmission of another impulse.

(b) Mechanism of vision: For seeing clear distant object it is essential that image must be focussed on the retina so that photoreceptor rods and cones are stimulated. Rays of light from the object fall on the biconvex lens after passing through the conjunctiva, cornea and pupil. The size of the pupil regulates the amount of light entering the eyeball. Thus, an inverted image of the object is formed on the retina which is conveyed to the brain by the optic nerve. The image is then reinverted by the brain.

The eyes have got the property to form image of both far and near objects on retina by changing the convexity of the lens. This is called power of accommodation.

(c) Mechanism of hearing: The sound waves first strike the pinna which keeps on moving to direct the sound waves into tympanic cavity. These waves then strike the tympanic membrane which starts vibrating due to which the ear ossicles are vibrated.

Thus it is transmitted the membrane over the fenestra ovalis into scala vestibule of the cochlea. In this way, the perilymph filled in it also gets vibrated due to which Reissner’s and basilar membranes start vibrating. By the vibration of these membranes, the endolymph of scala media also vibrates as well as the tectorial membrane.

Because of the vibration of endolymph of scala media, the sensory hairs of the receptor cells of the organ of Corti are stretched and bent due to which the receptor cells gets stimulated and send the impulses to the brain through cochlear nerve. In the manner the sound is heard.

Question 8.
(a) How do you see colour of any object?
(b) Which part of our body helps to maintain equilibrium (balance) of the body?
(c) How does eyes regulate light which falls into the retina.
Answer:
(a) Retina contain two types of light receptor cells: Rods and cones. In the presence of light rods perceive light, whereas the cones are colour receptors, containing adoption or visual violet. They function in strong light and are meant for scotopic vision (colour vision), that is why we can not see colour in dim light or dark.

On the basis of pigments there are three types of cones :

1. Cones respond to red light due to presence of erythroblast pigment.
2. Cones respond to green light due to presence of chlorolabe pigment.
3. Cones respond to blue light due to presence of cyanolabe pigment.
   The colour that we see results from a mixture of impulses of the above types of cone
   types.

(b) Ears play an important role in hearing and the maintenance of equilibrium and orientation of body, hence are called as balancing organ. Sensory cells are present in the ampullae of the semilunar canals and utriculus. Several particles of calcium carbonate or otoliths are scattered around the cilia of these cells. When the equilibrium of the body disturbed, the otoliths move and press upon the cilia or sensory cells which get stimulated and send the impulse to the brain. Thus brain receives the information and sends instructions to different organs to set right the equilibrium of body.

(c)

(a) Mechanism of synaptic conduction:
Nerve impulse: The sum total of the physical and chemical reactions which take place in the propagation of the wave of physiological activity along the nerve fibre is called as nerve impulse.

Propagation of Nerve impulse :

1. Depolarization: When a stimulus of any kind electrical, mechanical or chemical acts on the nerve fibre momentarily, a local increase occurs in the permeability of membrane by opening sodium gate at the site of stimulus. This suddenly brings sodium ions influx into the cell, carrying enough positive charges to the inside to cause complete disappearance of the normal resting potential and usually enough charges to develop a positive state inside the fibre. This positive state of the fibre is called reverse potential. It results in the depolarization of the membrane.

2. Action potential: The changed electrical potential of the plasma membrane of neuron is called action potential. The initial change produces an ionic imbalance across the membrane on either side of the points of stimulus producing local electrical current. These areas of negative depolarization in turn initiate changes in the membrane adjacent to them. A wave of electric charges or depolarization along the length of the nerve fibre or axon is called nerve impulse.

3. Repolarization: With the increase of positive charge inside further entry of Na⁺ is prevented and the permeability of membrane decreases. Na⁺ ions are pushed out which transfer large number of positive charge outside, once again creating negativity inside the membrane which restores the original resting potential. This is known as repolarization. The repolarization starts exactly on the same spot where depolarization had started and then continues to advance ahead. The entire process of repolarization requires some time during which the nerve cannot be stimulated again. It is known as refractory period.

Theories of nerve impulse conduction or Transmission :

1. Saltatory conduction or through nerve fibre : Myelin sheath acts as insulator in the medullated nerve fibres. It is almost impermeable to the ions. The membrane at the nodes of Ranvier is 500 times more permeable. The nerve impulse in these fibres passes from node to node along the entire length of nerve fibre rather than continuously along the entire fibre as occurs in unmyelinated fibre.

This process is called saltatory conduction. It is of dual value. First by causing the depolarization process to jump along nodes of Ranvier on the axis of the nerve fibre increases greatly the speed of impulse travel and secondly saltatory conduction conserves energy for the axon because only the nodes depolarize.
The velocity of conduction in nerve fibre varies from 5 metres per second in a small unmyelinated fibres to as high as 130 metres per second in large myelinated fibres.

Transmission of impulse across synapse (synaptic transmission): The area where the dendrite of one neuron is in close proximity with the axon of another is known as the synapse. The space between the axon and dendrite is called the synaptic cleft.

When the impulse reaches the tip of axon it stimulates the synaptic vehicles which move towards the synaptic cleft and discharge the neurotransmitter or neurohormones.
They then return the knob and become recharged. This chemical neurotransmitter substance has been identified as acetylcholine. Once released the neurotransmitter diffuses across the synaptic cleft and becomes attached to chemo- receptors present on the dendrites of the next neuron.

This attachment triggers the depolarization of the membrane and initiates action potential which travels across the next neuron. Thus, the actual transmission of the impulse across the synapse is by means of specific chemicals. Just after the transmission of impulse through the synapse, acetylcholine is hydrolyzed into acetic-acid and choline by the enzyme acetylcholinesterase present in the post synaptic membrane. The membrane again becomes polarized, so another impulse must come down the axon and release more acetylcholine for the transmission of another impulse.

(b) Mechanism of vision: For seeing clear distant object it is essential that image must be focussed on the retina so that photoreceptor rods and cones are stimulated. Rays of light from the object fall on the biconvex lens after passing through the conjunctiva, cornea and pupil. The size of the pupil regulates the amount of light entering the eyeball. Thus, an inverted image of the object is formed on the retina which is conveyed to the brain by the optic nerve. The image is then reinverted by the brain.

The eyes have got the property to form image of both far and near objects on retina by changing the convexity of the lens. This is called power of accommodation.

(c) Mechanism of hearing: The sound waves first strike the pinna which keeps on moving to direct the sound waves into tympanic cavity. These waves then strike the tympanic membrane which starts vibrating due to which the ear ossicles are vibrated.

Thus it is transmitted the membrane over the fenestra ovalis into scala vestibule of the cochlea. In this way, the perilymph filled in it also gets vibrated due to which Reissner’s and basilar membranes start vibrating. By the vibration of these membranes, the endolymph of scala media also vibrates as well as the tectorial membrane.

Because of the vibration of endolymph of scala media, the sensory hairs of the receptor cells of the organ of Corti are stretched and bent due to which the receptor cells gets stimulated and send the impulses to the brain through cochlear nerve. In the manner the sound is heard.

Question 9.
Describe functions of various parts of brain.
Answer:
Functions of different parts of brain :
Human brain consists of three parts :

1. Fore-brain,
2. Mid-brain,
3. Hind-brain.

Their functions are as follows :
1. Fore-brain:

(A) Cerebrum :

• It is the center of intelligence and reasoning.
• It is the centre of memory.
• It regulates feeling.
• Different area of this part is responsible for specific function.

(B) Olfactory lobe: It is the centre of reflex action.
(C) Diencephalon :

• It recognizes the sensation such as heat, cold and pain.
• It regulates metabolism of carbohydrates and fats.
• It regulates blood pressure.
• It also regulates hunger, thirst, sleep, temperature, tiredness, hate and satisfaction feeling by autonomic nervous system present in it.

2. Mid-brain : It helps to receive stimuli of vision and hearing. ‘
3. Hind-brain :
(A) Cerebellum :

• It regulates contraction and relaxation of muscles.
• Regulates balance of the body.

(B) Medulla oblongata :

• Regulates all involuntary functions such as heartbeat, rate of respiration and contraction of alimentary canal.
• It regulates swallowing, vomiting, sneezing etc.

Question 10.
Write differences between following :
(a) Myelinated and Non-myelinated nerve fibre.
(b) Dendrites and Axon.
(c) Rods and Cones.
(d) Thalamus and Hypothalamus.
(e) Cerebrum and Cerebellum.
Answer:
(a) Differences between Myelinated and Nonmyelinated nerve fibre

(b) Differences between Dendrites and Axon

(c) Differences between Rods and Cones

(d) Differences between Thalamus and Hypothalamus

(e) Differences between Cerebrum and Cerebellum

Question 11.
Write differences between following. (NCERT)
(a) Afferent neuron and Efferent neuron.
(b) Impulse conduction in Myelinated and Non-myelinated nerve fibres.
(c) Yellow spot and Blind spot.
(d) Aqueous humour and Vitreous humour.
(e) Cranial nerves and Spinal nerves.
Answer:
(a) Differences between Afferent neurons and Efferent neurons

(b) Differences between Impulse conduction in Myelinated and Nonmyelinated nerve fibres

(c) Differences between Yellow spot and Blind spot

(d) Differences between Aqueous humour and Vitreous humour

(e) Differences between Cranial nerves and Spinal nerves

Question 12.
How many cranial nerves are found in human? Give their name, nature, distribution and functions.
Answer:
Cranial nerves: In human 12 pairs of cranial nerves are found. Their name, nature, distribution and functions are as follows:

Question 13.
What is reflex action? Give its types. Describe mechanism of reflex action and give its importance.
Or,
What is reflex action? Draw well-labelled diagram of reflex action. Also explain the process of reflex action along with suitable example.
Answer:
Reflex action: The reflex actions are involuntary or unconscious response to a stimulus. They are brought about by reflex arc when a receptor is stimulated.

There are two types of reflexes :

1. Unconditional reflex: These are inborn reflexes and the nerve paths are the reflex arc fixed from the birth of the organism. They do not involve any thinking of brain, e.g. salivation of mouth, blinking of eye, knee jerk, etc. Complex in bom reflexes are called as instincts e.g. reproductive behaviour.

2. Conditional reflex: These are not inborn, but they can be acquired through practice or past experience.
Ventral fissure

Mechanism of reflex action: A reflex arc comprises of some specific receptors, afferent neurons, connector or intermediate neurons, efferent neuron and effector organ. The impulses from the receptors pass on to the CNS through the afferent fibres whose axons terminate in the grey matter of either brain or spinal cord. In the grey matter these impulses are transferred to the motor neurons to carry out the specific action directly without any association neuron or they may be passed through one or many intermediate neurons to the effector organ. If a synapse is formed between the afferent and efferent fibres without a intermediate neuron it is known as mono synaptic reflex arc.

When there are two synapses, one between the afferent fibre and intermediate neuron and the other between the intermediate neuron and efferent fibre, it is known as bisynaptic reflex arc. The involvement of more than two intermediate neurons form a polysynaptic reflex arc. The involvement of more than two intermediate neurons form a polysynaptic reflex arc.

Some simple reflex actions:
1. Knee jerk: When patellar tendon is tapped, a quick jerk of the leg occurs.
2. Coughing or sneezing all of a sudden.
3. Withdrawal of hand or leg when it is pricked with a needle.
4. Blinking of eyelids when some object approaches the eye.
5. The quick recovery of balance of body after a sleep.

Importance of reflex action:
1. It takes less time as the process is regulated by spinal cord thus protect the body from accident.
2. Body of organism is protected all of a sudden.
3. Brain get more time to control other functions as reflex action is regulated by spinal cord.

Neural Control and Coordination Class 11 Important Questions Objective Type

1. Choose the correct answers:

Question 1.
Which of the following is the immediate covering of a nerve fibre :
(a) Sarcoplasm
(b) Perineurium
(c) Epineurium
(d) Endoneurium.
Answer:
(d) Endoneurium.

Question 2.
In humans, one of the following cranial nerves is associated with the sense of body balance:
(a) VI
(b) VII
(c) VIII
(d) IX.
Answer:
(c) VIII

Question 3.
If a person has lost his memory in an accident, the following part of the brain have got injured :
(a) Diencephalon
(b) Medulla oblongata
(c) Cerebellum
(d) Cerebrum.
Answer:
(d) Cerebrum.

Question 4.
Parasympathetic nervous system :
(a) Increases heartbeat
(b) Decreases heartbeat
(c) Originates heartbeat
(d) Has no effect upon heartbeat.
Answer:
(b) Decreases heartbeat

Question 5.
Brain is:
(a) Ectodermal
(b) Mesodermal
(c) Endodermal
(d) Mesoendodermal.
Answer:
(a) Ectodermal

Question 6.
The nervous strip connecting both the cerebral hemispheres in the rabbit is:
(a) Corpus callosum
(b) Corpus Albicans
(c) Corpus striatum
(d) Corpus spongiosum.
Answer:
(a) Corpus callosum

Question 7.
The thermoregulatory centre is situated in :
(a) Spinal cord
(b) Pituitary body
(c) Cerebellum
(d) Hypothalamus.
Answer:
(d) Hypothalamus.

Question 8.
The neurotransmitter which communicates between two neurons or between a neuron and a muscle is :
(a) Acetylcholine
(b) Globulin
(c) Rennin
(d) ATP.
Answer:
(a) Acetylcholine

Question 9.
What is found in the periphery of spinal cord :
(a) Grey matter
(b) Myelinated nerve
(c) White matter
(d) Notochord.
Answer:
(c) White matter

Question 10.
Which is correct about human brain :
(a) It is covered by two membranes
(b) There is no blood-brain barrier
(c) Largest number of cranial nerves originate from cerebral hemisphere
(d) Cerebral cortex is highly developed.
Answer:
(d) Cerebral cortex is highly developed.

Question 11.
Heart is innervated by :
(a) Trigeminal
(b) Vagus
(c) Glossopharyngeal
(d) Facial.
Answer:
(b) Vagus

Question 12.
Parotid gland located at the base of ear secretes :
(a) Wax
(b) Saliva
(c) Hormone
(d) Enzyme.
Answer:
(a) Wax

Question 13.
Tongue is controlled by :
(a) Trigeminal nerve
(b) Facial nerve
(c) Glossopharyngeal nerve
(d) None of the above.
Answer:
(b) Facial nerve
(c) Glossopharyngeal nerve

Question 14.
The co-ordination system of the body is :
(a) Blood vascular system
(b) Nervous system
(c) Endocrine system
(d) Nervous and Endocrine system.
Answer:
(d) Nervous and Endocrine system.

Question 15.
Synapse occurs in between :
(a) Nerve and muscles
(b) Two nerves
(c) Two nerve fibres
(d) One nerve fibre and neuron.
Answer:
(b) Two nerves

Question 16.
Which part out of the following is found covered with fatty covering :
(a) Axon
(b) Cyton
(c) Dendrite
(d) Node of Ranvier.
Answer:
(a) Axon

Question 17.
Sequence of ear ossicles is :
(a) Incus Malleus stapes
(b) Stapes incus malleus
(c) Malleus incus stapes
(d) None of the above.
Answer:
(c) Malleus incus stapes

Question 18.
Part of the eye of vertebrate from where optic nerve comes out: (NCERT)
(a) Phobia
(b) Iris
(c) Blind spot
(d) Optic chiasma.
Answer:
(c) Blind spot

2. Fill in the blanks:

1. The junction present between two neurons is called ……………… .
Answer:
Synapsis,

2. Acetyl, choline is a ……………… .
Answer:
Neurotransmitter,

3. In human being ……………… pairs of spinal nerves and ……………… pairs of cranial nerves are found.
Answer:
31, 12,

4 ……………… is originated from optic nerve.
Answer:
Blindspot,

5. The cones of light are sensitive to only ……………… light.
Answer:
Bright,

6. All the nerves coming out of the spinal cord are ……………… nerves.
Answer:
Mixed,

7. Internal ear is made up of ……………… labirynth and ……………… labirynth.
Answer:
Bony, Membranous,

8. The eyes of nocturnal animals contain only ……………… .
Answer:
Rods,

9. Eustachian tube is found in the ……………… .
Answer:
Middle ear,

10. Corpus callosum is found in the ……………… .
Answer:
Human brain

3. Match the following:

(A)

Answer:
1.  (c) Brain,
2. (d) Choclea
3. (e) Thinking.
4.  (b) Reflex action
5.  (a) Respiratory centre

(B)

Answer:
1.  (c) Balance
2. (a) Colour
3. (e) Smell.
4. (b) Internal ear
5. (d) Duramater.

4. Write true or false :

1. Name the part of retina which contains only cones.
Answer:
Yellow spot,

2. Give an example of general reflex action.
Answer:
Blinking of eyes,

3. Write the name of fluid present in eye.
Answer:
Aqueous and vitreous humous,

4. Write the name of nerve responsible for the movement of tongue.
Answer:
Hypoglacel nerve,

5. Write the name of smallest bone of human ear.
Answer:
Stapes,

6. Write the number of cranial and spinal nerves found in a human.
Answer:
12 pairs, 31 pairs,

7. Name the pigment which is helpful in vision during night.
Answer:
Rhodopsin, [photopic vision (black and white)]

8. Name the pigment present in the skin.
Answer:
Melanin,

9. The black colour of elephant indicates which place it lives.
Answer:
9. Hot places.

Students get through the MP Board Class 11th Biology Important Questions Chapter 2 Biological Classification which are most likely to be asked in the exam.

MP Board Class 11th Biology Important Questions Chapter 2 Biological Classification

Biological Classification Class 11 Important Questions Very Short Answer Type

Question 1.
Name one bacterial disease of human and give name of the causal organism.
Answer:
A bacterial disease of human is Typhoid. It is caused by Salmonella typhi.

Question 2.
Name any two Nitrogen fixing bacterias.
Answer:
Two Nitrogen fixing bacterias are :

1. Azobactor,
2. Rhizobium.

Question 3.
Give one example of each :

1. Gram positive bacteria,
2. Gram negative bacteria,
3. Sulphur bacteria,
4. Iron bacteria,
5. Nitrifying bacteria,
6. One mycoplasm,
7. One Cyanobacteria,
8. Bacteria used for making curd from milk,
9. One antibiotic bacteria.

Answer:

1. 1. Gram positive bacteria : e.g., Diplococcuspneumonae,
   2. Gram negative bacteria : e.g., E. coli,
   3. Sulphur bacteria : e.g., Thiobacillus,
   4. Iron bacteria : e.g., Ferrobacillus,
   5. Nitrifying bacteria : e.g., Nitrosomonas,
   6. One Mycoplasm : e.g., E. coli plasma,
   7. One Cyanobacteria : e.g., Nostoc,
   8. Bacteria used for making curd from milk: e.g., Lactobacillus,
   9. One antibiotic bacteria : e.g., Streptomyces.

Question 4.
What are archaebacteria?
Answer:
Archaebacteria:
Archaebacteria is a group of primitive bacteria, the cell wall of which is made up of polysaccharide and proteins and its cell membrane contains branched chains. This type of cell membrane protects bacteria from abnormal temperature and pH and thus it can survive in abnormal environmental conditions, hence it is called the organism of abnormal conditions. They can live in those places and under conditions where other organisms are unable to survive. These bacteria are a type of primitive organism that are also found today in its old or primitive atmospheric conditions only hence they are called as ‘living fossils’.

Question 5.
What are cyanobacteria?
Answer:
Cyanobacteria are the filamentous gram-negative blue-green bacteria which contains chlorophyll-a, chlorophyll-c, c-phycocyanin, c-phycoerythrin and carotenoids. Their cells exhibit prokaryotic cell structure, e.g., Nostoc, Anabaena, Rivularia, etc.

Question 6.
What do you mean by sulphur bacteria?
Answer:
Those bacteria which depend upon inorganic substance or H2S to obtain energy is known as sulphur bacteria. Thiobacillus thioxidans, oxidises Sulphur to Sulphate state in order to obtain energy. These bacteria can bear strong acidic medium.

Question 7.
What are plasmid and episomes?
Answer:
The cytoplasm of the bacterial cells also contains some extranuclear hereditary units (DNA) other than nuclear DNA. These extranuclear or extrachromosomal units are called as plasmids. When these plasmids get associated with bacterial genome, it is called episome. These hereditary units participate in genetic transmission and genetic recombination.

Question 8.
Write any three important features of mycoplasma.
Answer:

1. They are ultramicroscopic, parasitic and pleuromorphic organisms.
2. It is a cell wall less prokaryotic organism.
3. Movement and locomotion is absent and they may be globular to branched.

Question 9.
Which characteristics of fungi are similar to man?
Answer:
Fungi are heterotrophs like human and stored food in them is glycogen like human.

Question 10.
What do you understand by symbiotic plants?
Answer:
Symbiotic plants: Plants of two different species which lives together throughout the whole life to benifit each other are called as Symbiotic plants.
e.g., Lichen, which is an association of algae and fungi. Algae provide prepared food to fungi and fungi provide absorbed minerals and water to the algae.

Question 11.
Give full form of LSD. Name the fungi from which it is obtained.
Answer:
Full form of LSD is Lysergic acid Dimethyl Amide. It is obtained from a fungi called as Claviceps. It is a harmful drug.

Question 12.
Name the genera of fungi from which Penicillin antibiotic is obtained.
Answer:
From Genera Penicillum of fungi Penicilium notatum, antibiotic penicilin is obtained.

Question 13.
What are the components of Lichen?
Answer:
Lichen is an association of algae and fungi. Algae partner is called as Phycobiont which belongs to Chlorophyta and fungi partner is called as Mycobiont which belongs to Ascomycetes or Basidiomycetes.

Question 14.
Give characteristics of cell wall of fungi.
Answer:
Cell wall of fungi is made up of a nitrogen containing polysaccharide called as Chitin.

Question 15.
How Lichen is useful in formation of soil?
Answer:
Lichen is able to invade the bare rocks and help to break it and help for formation of soil. It makes the environment suitable for other forms of life also. They play important role in xerophytic plant succession.

Question 16.
Fungi of which class are called as Algal fungi?
Answer:
Fungi of Phycomycetes class are called as Algal fungi.

Question 17.
Which fungi are called as Moulds?
Answer:
Fungi belongs to Phycomycetes and Ascomycetes are called as Moulds.
e.g., Mucor, Aspergillus, Penicillium.

The Biological Classification Class 11 Important Questions Short Answer Type

Question 1.
Draw a well labelled diagram of a bacterial cell.
Answer:

Question 2.
Describe two living and non-living characters of viruses.
Answer:
Living characters of viruses :

• Viruses possess the capacity of growth, reproduction and adaptation.
• Found in living host as parasites and multiply within living host only and contain nucleic acids.

Non-living characters of viruses :

• They do not have protoplasm and enzyme system, hence metabolic activities absent. “
• They can be crystallized.

Question 3.
Draw a well labelled diagram of Cyanobacteria.
Answer:

Question 4.
Write down any five characteristic features of kingdom monera.
Answer:
Characteristic features of kingdom monera :

• The cells of organism of this kingdom are prokaryotic.
• Bilayered membranous organelles are absent.
• They reproduce asexually but protosexual process is formed in the form of gene recombination.
• A hard cell wall is present around cells.
• They can easily survive in unfavourable conditions.

Question 5.
Describe the types of archaebacteria on the basis of their survival in unfavourable conditions.
Answer:
Archaebacteria are of following three types on the basis of their survival in unfavourable conditions :

1. Methanogens :
   Anaerobic bacteria that produce methane from C02 and Formic acid are called as methanogenic bacteria.
2. Halophytes:
   These bacterias are found in concentrated salt solution. Methanogens and halopuyles are obligate anaerobes and form together anaerobic group of archaebacteria.
3. Thermoacidophyles :
   These are a type of aerobic or anaerobic archaebacteria that are found in sulphur containing hot water falls. They convert Sulphur into Sulphuric acid (H₂SO₄) in aerobic co ditions while into H₂S in anaerobic conditions.

Question 6.
Give the difference between Gram-positive and Gram-negative bacteria.
Answer:
Differences between Gram-positive and Gram-negative Bacteria

Question 7.
Explain the Role of Monera in Cycling of Matters.
Answer:
Role of Monera in Cycling of Matters : Cycling of matter through living organisms and environment is a continuous process. Elements or matters are renewed in the nature due to cycling of matter.

All the living organisms use different elements such as : C, H2, N2, S, 02, etc. from nature to perform its life activities. Carbon cycle, oxygen cycle, nitrogen cycle, sulphur cycle are natural processes involving producers, consumers and decomposers. Decomposers of kingdom Monera and Fungi play an important role in cyclic transformation of matters. Majority of the decomposers are bacteria which are Monerans. They decompose the organic matter of dead bodies by enzymatic action and release the constituent inorganic elements, which are again used up by plants thus cycling of matter continues.

Question 8.
Write the names of any five pathogenic bacteria form and diseases caused by them.
Answer:
Bacterial diseases of Man

Question 9.
List the names of any five pathogenic bacteria for plants and diseases caused by them.
Answer:
Bacterial diseases of Plants

Question 10.
Classify bacteria on the basis of nutrition. Write only names.
Answer:
Bacteria are classified into following three groups on the basis of nutrition :
1. Autotrophic bacteria:
(a) Photoautotrophic bacteria.
(b) Chemoautotrophic bacteria:

• Sulphur bacteria,
• Iron bacteria,
• Nitrifying bacteria,
• Hydrogen bacteria.

2. Heterotrophic bacteria :
(a) Obligate parasite.
(b) Facultative parasites.
(c) Saprophytic bacteria.
(d) Facultative saprophytic bacteria.

3. Symbiotic bacteria.

Question 11.
Draw well-labelled diagram of bacteriophage.
Answer:

Question 12.
According to shape; how many types of bacteria are there, name them ?
Answer:
According to shape, bacteria are of following types :
(A) Cocci (Sperical or Oval shape): It is of following types :

1. Diplococcus,
2. Tetracoccus,
3. Staphylococcus,
4. Streptococcus, (5) Sarcina.

(B) Bacilli or Bacillus (Rod shaped) :

1. Diplobacillus,
2. Streptobacillus,
3. Bacillus,
4. Palisade bacillus.

(C) Spirillum :

1. (1) Vibrio,
2. Hellical,
3. Comma.

Question 13.
Write down the difference between Plant virus and Animal virus.
Answer:
Differences between Plant and Animal Virus

Question 14.
Name some antibiotics produced by bacteria.
Answer:
Antibiotics produced by bacteria

Question 15.
What are viruses? Explain their significance in brief.
Answer:
Viruses :
Viruses are the ultramicroscopic prokaryotic organisms, made up of nucleoproteins and are visible only under electron microscope. They are living and non-living both. When they come into contact of living host they behave as a living matter.

Economic importance of viruses:
Viruses are very harmful organisms as these cause various diseases in plants and animals.
(a) Plant diseases :

• Tobacco mosaic disease,
• Greening of banana,
• Leaf curl disease of papaya,

(b) Human diseases :

• Polio,
• Measles,
• AIDS,
• Influenza.

(c) It is used to prove the organic evolution as it is the connecting link of living and non-living things.

(d) Cyanophases are responsible for the sanitation of blue-green algae.

(e) Harmful bacteria can be killed by bacteriophages.

Question 16.
What is Herbarium ? Write its importance.
Answer:
Herbarium is the group of plants in which flowers, leaves are spread and kept inside the paper, as paper absorbs the water molecules and make it dry, so that it can be arranged serially and studied with reference.

Importances : Importance of herbarium are :

• Due to herbarium, it become easy to identify the plants.
• Due to herbarium, we are able to get seasonal plants to study.
• Due to herbarium, by monographics phytogeographic, we are able to study the plant.
• Due to herbarium we get the preserved plants to study.

Question 17.
Give some harmful activities of bacteria.
Answer:
Some harmful activities of bacteria are as follow :

• Disease :
  Bacteria cause many dangerous diseases in human beings, animals and plants.
• Denitrification :
  Denitrification is a process in which nitrogenous compounds are converted into free nitrogen by the activity of Pseudomonas bacteria.
• Food poisoning:
  Some bacteria cause food poisoining. e.g., Clostridium botulinum.

Question 18.
Write differences between Virus and Viroids.
Answer:
Differences between Virus and Viroids

Question 19.
Give characteristics of cell wail of Diatoms.
Answer:
Diatoms have a cellulose cell wall impregnated with glass like silica. The cell wall consists of two overlapping halves that fit together like a soap box.
When diatoms die their siliceous cell walls accumulate at the bottom of the ocean forming diposists of fossil diatoms known as diatomaceous earth. The powdered diatomaceous earth is used as materials for polishing silver and filtration to clarify oils, syrups etc.

Question 20.
What are Algal Bloom and Red tides.
Answer:
Algal Bloom :
Sometime algae like Caulepra, Spirogyra etc. grows in large number in water and makes it green coloured. In such condition it is called as Algal Bloom.

Red tides :
Red coloured dianoflagellates like desmids are found in fresh and salty water. Sometime they grows in large number in the sea water due to which the sea appears red coloured. Thus tides appears red and it is called as Red tides.

Question 21.
Give Two economic importance of:
(a) Eubacteria and
(b) Archaebacteria.
Answer:
(a) Eubacteria :

• Nitrogen fixation : Some free living bacteria like Clostridium, Azobactor and Symbiotic bacteria like Rhizobium help for Nitrogen fixation.
• Nitrifying bacteria : Some bacteria like Nitrosomonas convert ammonia into nitrite and Nitrobactor converts nitrite into nitrate.
• Decomposition of Dead organism : Some bacteria increase soil fertility by the decomposition of dead organic matter.
• In dairy industry : Bacteria also converts the lactose sugar of milk into curd or lactic acid.
• Medicine industry : Various types of antibiotics and enzymes are obtained from bacteria, e.g., Streptomycin.

(b) Archaeobacteria:

• Methanogenes : These are anaerobic bacteria. They form methane (CH4) from CO₂ or formic acid.
• Halophiles : These are anaerobic bacteria, found in brine called as halophiles.
• Themoacidophiles: They are aerobic bacteria, can leave at very high temperature (80°C). They oxidise Sulphur to Sulphuric acid and make the environment highly acidic (pH-2). Under anaerobic conditions some forms can reduce Sulphur to Hydrogen Sulphide.

Question 22.
What do you mean by Phycobiont and Mycobiont?
Answer:
In Lichen, Algae partner is called as Phycobiont which are autotrophs and provides food to fungi partner. Fungi partner is called as Mycobiont which are heterotrophs. They provide absorbed minerals and water to the phycobiont.
An association of algae and fungi is called as Lichen.

Question 23.
Give comparative description of divisions of Kingdom fungi under following
points
(a) Method of Nutrition,
(b) Method of reproduction.
Answer:

Question 24.
Give characteristic features of Euglenoids.
Answer:
Characteristics of Euglenoids :

• They are fresh water organisms.
• Cell wall is not found in them.
• Outer membrane is called as Pellicle.
• They have a whip like flagellum.
• They contain chlorophyll, thus can prepare food by photosynthesis process but in absence of light they shows holozoic nutrition. e.g., Euglena.

Biological Classification Class 11 Important Questions Long Answer Type

Question 1.
Explain the process of asexual reproduction in bacteria with suitable diagrams.
Answer:
Asexual reproduction in bacteria : In bacteria asexual reproduction is accompanied by the following methods :
(i) By endospores :
Endospores are formed during unfavourable conditions. At the time of endospore formation the cytoplasm of bacteria cell contracts to become rounded and a thick protective layer is formed around it. This structure is called endospore. On return of favourable conditions they germinate to produce a new bacterial cell.

(ii) By zoospores:
This type of asexual spore is formed by the division of cytoplasm.
Cytoplasm of bacterial cell divides to form many zoospores. On rupturing cell wall these zoospores are liberated and germinate to form Zoospores formation
a new bacterial cell.

(iii) By conidia:
Few filamentous bacteria produce conidia. On germination they form a new bacterial cell.

Question 2.
Describe any seven useful activities of bacteria along with examples.
Or
Write five useful activities of bacteria.
Answer:
Useful activities of bacteria :

• N₂ fixation : Some bacteria play an important role in nitrogen fixation. e.g.,Azoto- bactor, Clostridium, Rhizobium. These bacteria increase the fertility of soil by the fixation of atmospheric nitrogen.
• Lactic acid synthesis : Lactobacillus lacti converts the milk sugar into lactic acid.
• Acetic acid synthesis : Acetobactor acetii takes part in synthesis of acetic acid or vinegar.
• Rating of fibres : Isolation of wood fibres from the stem of plants is called rating. Clostridium butyricum is used in rating of fibres.
• Tobacco and tea industry : Some bacterias like Micococcus candisens is used to increase the flavour of the leaves of tobacco and tea. This process is called as seasoning.
• Medicine production : Bacteria are the chief source of antibiotics, hence they are used to extract antibiotics, e.g., Streptomyces gresius (Streptomycin).
• As symbionts: Bacteria present in our body help in the various metabolic reactions. e.g., E. coli.

Question 3.
Describe the economic importance of bacteria.
Or
Write an essay on economic importance of bacteria.
Or
Justify the statement that “bacteria are our friend as well as enemy”.
Answer:
Bacteria are of great economic value in our daily life. They are useful as well as harmful. A large number of bacteria are employed in the manufacture of various industrial products. Many bacteria are harmful to human affairs in many ways because they produce many dangerous diseases in human beings and animals. Thus bacteria are our friend as well as enemy.

Useful activities :

• They increase the fertility of soil by N₂ fixation.
• They help in the formation of curd from milk.
• They play an important role in vinegar industry, tobacco industry, leather and medicine industry.
• They help in the obtaining of stem fibres and are found as symbionts in our body.

Harmful activities :

• They produce various types of diseases in men, animals and plants.
• They reduce the fertility of soil by denitrification.
• They destroy the food and make them toxic.

Question 4.
Describe viruses on the basis of their structure and the genetic material found in them. Give names of four diseases caused by viruses.
Answer:
Structure of viruses :
Virus, a Latin word which means poison was discovered by Iwanowsky (1892). Viruses are intercellular parasites with protein and nucleic acid in their structure. They are ultramicroscopic structure ranging from 10µ to 300µ in size.

Structurally viruses are made up of the following two parts :

• Proteinaceous capsids and
• Nucleic acid.

The size of TMV is about 15× 300µ( 150 x 3000Å) which is made up of protein and RNA. The outer covering of TMV is made up of proteins which is known as capsid. Each capsid is made up of many smaller proteins.

Types of viruses: Viruses are classified on the basis of:

1. Type of host,
2. Type of disease,
3. Type of nucleic acids.

Viruses are of following 4 types on the basis of their host or parasitism :
1. Animal viruses (Zoophagineae) : They infect animals and humans. They have mostly DNA as genetic material.
2. Plant viruses (Phytophagineae): They infect plants only. They have mostly RNA as genetic material which is single or double-stranded.

Diseases caused by viruses :
1. Plant diseases :

• Tobacco Mosaic disease,
• Green disease in banana.

2. Diseases in human :

• Polio,
• Measles,
• Influenza.

Question 5.
Write down the symbiotic forms of Monera.
Answer:
Symbiotic Forms:
Organisms living together with mutual beneficial association are called Symbionts and this phenomenon is known a Symbiosis. There are following forms of Symbionts:
1. Mutualism :
When two or more organism living together with beneficial associa-tion it is called mutualism, e.g., Lichens. The body of lichens is made up of a fungus and a cyanobacteria. Cyanobacteria manufacture food for fungi and fungi absorb water and min¬erals for cyanobacteria.

2. Symbiotic:
When two organism living together in such way that only one organism take benefits from other, e.g., Symbiotic association of yeast and bacteria during the fermentation of vinegar or acetic acid. Here yeast cells ferment sugar into alcohol and bacteria ferment alcohol into acetic acid. Thus, bacteria take benefits from yeast cells.

3. Symbiosis :
When two organisms living together with beneficial association but both survive separately also, e.g., symbiosis between Rhizobium leguminosarum and roots of leguminous plants.

The members of Monera exhibit symbiosis with both the plants and animals. Few examples are given below :

• All insects sucking juice of plants and blood contain symbiotic bacteria.
• Micrococcus cerolyticcus and Candida albicans bacteria are found in the alimentary canal of birds eating wax of honey-bee comb. These bacteria decompose wax into simple organic compounds.
• E. coli is found in the intestine of human beings, it helps in digestion.

Question 6.
Explain the autotrophic bacteria.
Answer:
Some bacteria are able to synthesize their food so they are autotrophic in their mode of nutrition. On the basis of sources of energy these are of two types :
1. Photoautotrophic bacteria:
These anaerobic photosynthetic bacteria may be rods, cocci or spirilla depending upon their colouration. They are known as green or purple bacteria. They use sunlight as source of energy for photosynthesis but like other eukaryotic cells they do not split water to transfer the energy or to obtain reducing power.

Thus, no oxygen is evolved by them. This process is, therefore, called anoxygenic (without producing oxygen) photosynthesis. In place of water these bacteria obtain reducing power from hydrogen sulphide, thiosulphate, hydrogen or even some organic compound. The photoautotrophic bacteria are further classified into two categories on the basis of hydrogen donor.

(a) Photolithotrops :
Here hydrogen donor is an inorganic substance.
Examples :
(i) Green sulphur bacteria :
These bacteria utilize H2S as hydrogen donor. They possess a chlorophyll called chlorobium chlorophyll. They synthesise their food in presence of light, e.g., Chlorobium.

(ii) Purple sulphur bacteria :
These bacteria utilize sulphur compounds as hydrogen donor. They contain a chlorophyll called bacteriochlorophyll. They synthesise their food in presence of light.

(b) Photo-organolithotrophs :
These bacteria use non-sulphur compounds as organic acids and alcohol as hydrogen donor, e.g., purple non-sulphur bacteria like Rhodospirillum.

2. Chemoautotrophic bacteria :
Chemoautotrophs are the organisms which oxidize inorganic substances with molecular oxygen to obtain the energy in the form of ATP. As they do not have pigment they cannot make use of light energy. The energy of ATP is utilized to reduce carbon dioxide to organic matter, so the source of carbon for these organisms is carbon dioxide, hence they do not need any organic compound as their food material.

They are also of two types :
(a) Chemolithotrophs :
These bacteria utilize the energy released by oxidation of inorganic substances. They are of following kinds :
(i) Sulphur bacteria : Thiobacillus thioxidans oxidises sulphur to sulphate state in order to obtain energy.

(ii) Nitrifying bacteria:
They oxidize ammonia to nitrites and then into nitrates, e.g., Nitrosomonas, Nitrobactor, etc.

(iii) Iron bacteria:
They oxidize ferrous compound to ferric forms, e.g., Ferrobacillus, Ferroxidans.

(iv) Hydrogen bacteria :
They oxidize hydrogen to water. e.g., Bacillus pentotrophous.

(b) Chemo-organotrophs : These bacteria oxidize organic substance and utilize energy released during reaction. e.g., Methane bacteria like Methanococcus. This bacteria oxidize methane into CO₂ and H₂O.

Question 7.
Write short note on :
(a) Transformation,
(b) Transduction.
Answer:
(a) Transformation :
Diplococcus pneumoniae could transfer their characteristics of its strain to non-virulent strain of living bacterial. It was observed that it is due to transfer of genetic material (DNA) from dead bacteria to living bacteria. And thereby a virulent type acquires the virulent nature. When donor cells break apart then explosive release and fragmentation of DNA takes place. Some of these DNA enters the recipient cells and become a part of recipient DNA. Such type of migration of genetic material is called transformation.

(b) Transduction :
It is discovered by Zinder and Lederberg in 1952 in Salmonella typhimurium. Bacteriophages transfer genetic material from one bacterium to another. This type of genetic migration from one bacterium to another takes place through the agency of bacteriophage is called transduction.

Transduction like transformation involves the transfer of only small segment of bacterial DNA from donor to recipient. In transformation DNA transferred is naked but in transduction it is passed to recipient cell as a packet surrounded by the coat of bacteriophage. When a bacteriophage particle is formed inside a bacterium, it may have a piece of bacterial DNA into its head in place of its own DNA. The bacteriophage particle is released when the parent bacterial cell undergoes lysogeny. These released bacteriophages may infect new bacteria cell carrying into it, some of the genes of bacteria, thus unknowingly transfer the gene.

Question 8.
Explain the process of respiration in bacteria.
Answer:
Respiration in Bacteria : Bacteria are known to occur in every type of environment. Like all other organisms they also respire to obtain energy. Depending upon the requirement of oxygen for respiration, there are two types of bacteria :
1. Aerobic bacteria :
Some bacteria can respire only in the presence of oxygen and are called as aerobic bacteria. They cannot live without oxygen. Thus, they are also called as obligate aerobes, e.g., Bacillus subtilis.

2. Anaerobic bacteria:
Some bacteria respire in absence of oxygen and are called as anaerobic bacteria. They can live in absence of oxygen but cannot live in the presence of oxygen and thus they are called as obligate anaerobes, e.g., Clostridium botulinum.
Some bacteria can live in both, i.e., in presence or absence of oxygen and so are called as facultative bacteria.

Question 9.
Write down the difference between Bacteria and Cyanobacteria.
Answer:
Differences between Bacteria and Cyanobacteria

Question 10.
Explain the uses and types of virus.
Answer:
Uses of Viruses :

• As it forms a link between non-living and living thus it help us to understand organic evolution,
• Cyanophage (Blue-green algae viruses) are used to destroy blue-green algae grown in different areas.
• Bacteriophages are used as biocides to destroy many harmful bacterias present in polluted area.

For example :
Water of the river Ganga always remain pure and clean in bottles year after year due to presence of bacteriophage in it.
Nucleic acids of viruses : Viruses generally contain only one type of nucleic acid DNA or RNA. DNA is found in animal viruses, whereas RNA is found in plant viruses.

Human Immuno Virus (HIV):
It causes AIDS disease in human. Full form of AIDS is Acquired Immuno Deficiency Syndrome. This virus destroys immune system of the body, thus the patient of AIDS suffers from number of diseases at a time and at last he dies.
This virus is found surrounded by protein and a ring of RNA is found at the centre. Whole body of virus is surrounded by a covering of glycoprotein.

Type of Viruses : On the basis of host infected, viruses are grouped into following four groups :

1. Animal viruses : Viruses which infect animals are called animal viruses. These viruses contain DNA as genetic material.
2. Plant viruses : Viruses which infect plants are called plant viruses. These viruses contain RNA as genetic material.
3. Cyanophages : Viruses that infect blue-green algae are called cyanophages. These viruses contain RNA as genetic material.
4. Bacterial viruses or Bacteriophages : Viruses that infect bacteria are called as bacteriophages. They contain DNA as genetic materials.

Question 11.
Describe the process of reproduction in bacteriophages along with labelled diagrams.
Or
Explain the process of reproduction in viruses with the help of diagrams.
Answer:
Bacteriophages can reproduce only inside the host cells. During multiplication they infect bacterial cells (host). Their DNA enters the cell and then gets replicated. Multiplication involves the following steps :

• Infection : First of all bacteriophage infects bacterial cells and attaches on the surface of bacterial cell wall with the help of their tail fibres.
• Penetration : The bacterial cell wall present at the attachment site is dissolved to fonn a hole, through which genetic material (DNA) of the bacteriophage enters the bacterial cell.
• Biochemical multiplication : After reaching the nucleoid, the DNA of phage synthesizing mRNA. In turn this mRN A synthesizes viral protein in the cytoplasm of bacterial cell.
• Organization of virus : Proteins formed from /wRNA form the viral sheath and thus many bacteriophages are formed.

• Release : New bacteriophages formed inside the cell are then liberated due to the lysis of bacterial cell wall.

Question 12.
Explain changes in the system of classification with time.
Answer:
In different time different naturalists and philosophers provided different system of classification of organisms, which are as follows :
1. Linnaeus classification :
A Swedish biologist Carolus Linnaeus (1707-1778) classified all the living organisms into main kingdoms (Two kingdom classification) :

1. Kingdom Plantae and
2. Kingdom Animalia.

He also proposed Binomial nomenclature for giving scientific names to the organisms. In his book ‘Systema Naturae’ scientific names of 4378 organisms are given.

2. Artificial System of Classification :
Pliny adopted artificial system of classification for the first time in the first century AD. According to this system organisms are recognised on the basis of one or few superficial characters only. The characters were arbitraruy selected.
Pliny classified animals into two major groups :

1. Animals which are abie to fly and
2. Animals which can not fly.

On the basis of which butterfly, bats and birds came under same group. In the same way he classified Plants into four groups :

1. Herbs,
2. Under shrubs,
3. Shrubs and
4. Trees.

3. Natural System of classification :
This system was proposed by George Benthom (1800-1844) and Joseph Dalton Hooker (1817-1911). Natural system was based on many features of the organisms, so that its exact position and relationship with the c.’her organisms is properly established. Therefore a modem taxonomist uses many criteria to determine the position of organism in the plan of classification.
The main object of this classification is to establish homology, i.e., relationship of comparable structure in different organisms.

4. Phylogenic system of classification :
It was proposed by A. Engier Karl, A. F. Prantle and John Hutchinson. This system is mainly based on the evolutionary and genetic relationships of the plants. It helps to find out the ancestors ‘r derivatives of any taxon.

Question 13.
Describe four classes of Phylum Protozoa.
Answer:
On the basis of locomotary organs Phylum protozoa is classified mto four classes, which are as follows:

1. Zooflagellates,
2. Sarcodina,
3. Sporozoa,
4. Ciliata.

1. Zooflagellata :

• Body is covered by pellicle,
• Body has definite shape,
• Locomotary organ is flagella,
• Generally uninucleate but soir, _ time multinucleate, e.g., Giardia, Trypanosoma.

2. Sarcodina or Rhizopoda:

• They are irreguk in shape,
• Locomotion by means of pseudopodia,
• They show holozoic nutrition,
• Uninucleate organism, e.g.,Ar. oebas.

3. Sporozoa :

• They are endoparasites,
• Pellicle is found surrounding the body,
• Locomotary organs are not found in them,
• motion of generation is found in them,
• They causes diseases.
  e.g., Plasmodium, Monocystis.

4. Ciliata :

• Body is covered by pellicle,
• Cilia are found 11 over the surface of tin ody and help for locomotion,
• Two nuclei are found in them. A large macronuclei and a small micronuclei,
• They show holozoic nutrition,
• Can reproduce asexually as sexually.
  e.g., Paramoecium.

Question 14.
Discuss about the topics in your class “Viruses are Living or non-living”.
Answer:
Viruses are the first organisms of the earth forming a connecting link between living and non-living as they posses characteristics of both living and non-living.
Living characters of Viruses :

• Growth and reproduction occurs in them,
• It contains nucleic acid (RNA or DNA),
• They show mutation,
• They cause diseases in plants and animals,
• They exhibit adaptation,
• They are parasitic in nature,
• They possess sensitivity.

Non-living characters of Viruses :

• Cells are absent,
• Cytoplasm is absent,
• They can be crystallized,
• Nutrition and metabolism is not found in them,
• They can not grow and reproduce out of the host cell,
• They lack enzymes.

Biological Classification Class 11 Important Questions Objective Type

1. Choose the correct answers:

Question 1.
Term ‘Species’ is coined by :
(a) John Ray
(b) Linnaeus
(c) Aristotle
(d) Charak
Answer:
(a) John Ray

Question 2.
Author of ‘Systema Naturae’ is :
(a) Bentham
(b) Hooker
(c) Linnaeus
(d) Engler.
Answer:
(c) Linnaeus

Question 3.
Author of ‘Species Plantarum’ is :
(a) Lamarck
(b) Linnaeus
(c) Theophrastus
(d) Yen.
Answer:
(b) Linnaeus

Question 4.
Five kingdom classification was proposed by :
(a) Aristotle
(b) Tippoa
(c) Birbal Sahni
(d) Whittakar.
Answer:
(d) Whittakar.

Question 5.
Who crystallized viruses for the first time :
(a) Stanley
(b) Guirer
(c) Whittakar
(d) Vigemic.
Answer:
(a) Stanley

Question 6.
Hereditary material of viruses is :
(a) DNA and RNA
(b) DNA or RNA
(c) Chromosome
(d) None of these.
Answer:
(b) DNA or RNA

Question 7.
Basic unit of classification is ;
(a) Class
(b) Species
(c) Genus
(d) Kingdom.
Answer:
(b) Species

Question 8.
Highest taxon of the classification is :
(a) Class
(b) Phylum
(c) Genus
(d) Species.
Answer:
(b) Phylum

Question 9.
Homo sapiens is the classification of:
(a) Man
(b) Bull
(c) Leech
(d) Frog.
Answer:
(a) Man

Question 10.
Hybrid organism produced from the cross between female horse and male donkey is :
(a) Monkey
(b) Rat
(c) Mule
(d) Horse.
Answer:
(c) Mule

Question 11.
Unit of classification is :
(a) Species
(b) Genus
(c) Both (a) and (b)
(d) None of these
Answer:
(a) Species

Question 12.
Binomial nomenclature system was proposed by :
(a) Darwin
(b) Carolus Linnaeus
(c) Hugo deVries
(d) Mendel.
Answer:
(b) Carolus Linnaeus

Question 13.
Author of ‘Genera Plantarum’ is :
(a) Bentham and Hooker
(b) Linnaeus
(c) Engler
(d) Prantle.
Answer:
(a) Bentham and Hooker

Question 14.
Naked seeds are formed in :
(a) Algae
(b) Pteridophytes
(c) Gymnosperm
(d) Angiosperm
Answer:
(c) Gymnosperm

Question 15.
Which of the following is most primitive vascular plant:
(a) Red algae
(b) Fem
(c) Brown algae
(d) Lichens
Answer:
(b) Fem

Question 16.
Basic unit of modern classification is :
(a) Species
(b) Genus
(c) Both
(d) None of these.
Answer:
(a) Species

Question 17.
Classification given by Linnaeus was artificial because :
(a) It is based on evolutionary tradition
(b) Similarity and dissimilarity in floral and other morphological characters are taken
(c) It is based on functional characters
(d) None of these.
Answer:
(b) Similarity and dissimilarity in floral and other morphological characters are taken

Question 18.
Phylogenetic classification is given on the basis of:
(a) Developmental history
(b) Floral similarities
(c) All morphological characters
(d) Increasing complexity.
Answer:
(a) Developmental history

Question 19.
First botanist of taxonomy is ;
(a) J. D. Hooker
(b) Engler
(c) Linnaeus
(d) Aristotle.
Answer:
(c) Linnaeus

Question 20.
Genus is the group of interrelated
(a) Families
(b) Species
(e) Order
(d) Genera.
Answer:
(b) Species

Question 21.
Basis of artificial classification is :
(a) One or two or more characters
(b) All possible characters
(c) Phylogenetic characteristics .
(d) None of these.
Answer:
(a) One or two or more characters

Question 22.
Objective of classification is :
(a) Collection of organisms
(b) Identification of organisms
(c) Discovery of animal
(d) Discovery, identification, nomenclature of organism and divide them into groups.
Answer:
(d) Discovery, identification, nomenclature of organism and divide them into groups.

Question 23.
Binomial nomenclature means writing name of organism in two words. These are :
(a) Type and species
(b) Order and species
(c) Type and variation
(d) Order and family.
Answer:
(a) Type and species

Question 24.
Who is known as father of classification :
(a) C. Darwin
(b) Lamarck
(c) Carolus Linnaeus
(d) Bentham and Hooker.
Answer:
(c) Carolus Linnaeus

Question 25.
A species can be defined as population of interbreeding individuals which are reproductively isolated from other species. Above statement was given by :
(a) Carolus Linnaeus
(b) Mayer
(c) J. B. Lamarck
(d) Charles Darwin.
Answer:
(b) Mayer

Question 26.
According to binomial system of nomenclature name of any plant consists of
how many words
(a) Three
(b) Two
(c) Five
(d) One
Answer:
(b) Two

Question 27.
Plant viruses have:
(a) DNA
(b) RNA
(c) DNA and RNA
(d) Coiled nuclear
Answer:
(b) RNA

Question 28.
Viruses contain:
(a) DNA
(b) RNA
(c) DNA or RNA
(d) Both DNA and RNA.
Answer:
(c) DNA or RNA

Question 29.
The viral capsid is made up of:
(a) Nucleic acids
(b) Proteins
(c) Lipids
(d) Carbohydrates.
Answer:
(a) Nucleic acids

Question 30.
In which plastids are not found :
(a) Blue-green algae
(b) Bacteria
(c) Fungi
(d) All of these.
Answer:
(d) All of these.

Question 31.
Sexual reproduction is absent in :
(a) Cyanobacteria
(b) Bacteria
(c) Eukaryote
(d) All of these.
Answer:
(a) Cyanobacteria

Question 32.
The viral capsid is made up of:
(a) Nucleic acid
(b) Proteins
(c) Lipids
(d) Carbohydrates.
Answer:
(b) Proteins

Question 33.
Which of the following disease is caused by bacteria
(a) T.B.
(b) Measles
(c) Small pox
(d) Polio
Answer:
(a) T.B.

Question 34.
Bacteria cell wall is made up of:
(a) Protein and cellulose
(b) Cellulose and fat
(c) Fat and protein
(d) Chitin and cellulose.
Answer:
(b) Cellulose and fat

Question 35.
Nostoc is a :
(a) Green algae
(b) Yellow-green algae
(c) Blue green algae
(d) Red algae.
Answer:
(c) Blue green algae

Question 36.
Transfer of DNA molecule by bacteriophage from one cell to another cell is called :
(a) Transformation
(b) Conjugation
(c) Mutation
(d) Transduction.
Answer:
(d) Transduction.

Question 37.
The amount of mucopeptides in the cell wall is highest in :
(a) Gram-positive bacteria
(b) Gram-negative bacteria
(c) Cyanobacteria
(d) Bacteriophages.
Answer:
(a) Gram-positive bacteria

Question 38.
Example of iron bacteria is :
(a) Beggiatoa
(b) Geobacillus
(c) Thiobacillus
(d) None of these.
Answer:
(d) None of these.

Question 39.
The causal organism of diphtheria is :
(a) Virus
(b) Eukaryotes
(c) Mycoplasma
(d) Bacteria.
Answer:
(d) Bacteria.

Question 40.
Which of the following statement is true for Mycoplasma :
(a) Absence of cell wall
(b) Presence of nucleus
(c) Presence of cell wall
(d) Definite shape.
Answer:
(a) Absence of cell wall

Question 41.
Nostoc is a:
(a) Cyanobacteria
(b) Beaded bacteria
(c) Bacteriophage
(d) Parasite.
Answer:
(a) Cyanobacteria

Question 42.
Leaf curl disease of potato is caused by :
(a) Mycoplasma
(b) Virus
(c) Microspore
(d) Bacteria.
Answer:
(a) Mycoplasma

Question 43.
Round bacteria is :
(a) Bacillus
(b) Cocci
(c) Spirillum
(d) Comma.
Answer:
(b) Cocci

2. Fill in the blanks:

1. …………………… is called as Father of Taxonomy.
Answer:
Carolus Linnaeus

2. The basic unit of classification is ………………..
Answer:
Species

3. Viruses are made up of protein and nucleic acid …………….. or ……………..
Answer:
DNA, RNA

4. The evolutionary history of any organism is called as …………………
Answer:
Phytogeny

5. Binomial nomenclature was proposed by ………………..
Answer:
Carolus Linnaeus

6. An association of algae and fungi is called as …………………..
Answer:
Lichen

7. …………………. proposed Five Kingdom classification.
Answer:
R.H. Whittakar

8. Connecting link organism between reptiles and birds is called as ………………..
Answer:
Archaeopteryx

9. Scientific name of man is ………………
Answer:
Homo sapiens

10. ……………. and ………………. tried for the first time to classify the organisms systematically.
Answer:
Hippocrates, Aristotle

11. …………………… described for the first time the Natural System of classification.
Answer:
John Ray

12. ……………… are the connecting link of living and non-living things.
Answer:
Viruses

13. Cell wall of fungi is made up of ……………..
Answer:
Chitin

14. ……………….. are called as living fossils.
Answer:
Archaebacteria

15. Stored food in fungi is ……………..
Answer:
Glycogen

16. Genetic material of Monerans is ………………..
Answer:
DNA

17. Minute prokaryotic structure is found in …………………
Answer:
Mycoplasma

18. Nitrifying bacteria are ……………….
Answer:
Saprophytic

19. Bacteria is discovered by ………………………
Answer:
Antony Van Leeuwenhoek

20. Bacteria, which are founds in human intestine is ………………..
Answer:
E. coli

21. The disease pneumonia is caused by ………………….
Answer:
Diplococcuspneumonae (Bacteria)

22. AIDS is caused by ………………. virus.
Answer:
Human immunodeficiency vims or HIV

23. ……………… are the extranuclear, circular DNA found in the bacterical cell.
Answer:
Plasmids

24. ………………. type of ribosomes are found in bacterial cells.
Answer:
70S

25. …………………………. bacteria are found in the root nodules of lenguminous plants, which help for N₂ fixation.
Answer:
Rhizobium

3. Match the following:

Match the following : (A)

Answer:
1. (d) Charak
2. (c) Heckle
3. (e) R.H. Whittakar
4. (b) John Ray
5. (a) Copland
6. (f) Carolus Linnaeus.

(B)

Answer:
1. (e) Occurs singly.
2. (c) Twisted like a screw
3. (b) Spherical or oval shape
4. (a) A chain of cells like strand of beads
5. (d) Prokaryotic multicellular

4. Write true or false:

1. Most of bacteria are heterotrophic due to absence of chlorophyll but some are photoautotrophic.
Answer:
True

2. Excess amount of sugar and salt destroys the substances present in Pickles and jelly.
Answer:
False

3. Bacteria found in human intestine is E. coli.
Answer:
True

4. Vims that infect blue-green algae are called animal vims.
Answer:
False

5. Vims is a link between living and non-living.
Answer:
True

6. Collection of plants specimens arranged in the sequence of an accepted classification is called as Herbarium.
Answer:
True

7. Addition of salt and sugar decay pickles.
Answer:
False

8. Multicellular organisms grows by mitosis cell division whereas Unicellular organisms multiply by this.
Answer:
True

9. Vimses can reproduce both in living and non-living.
Answer:
False

10. Tme nucleus is not found in Moneran.
Answer:
True

5. Answer in one word:

1. Name the organism possesses characteristics of living as well as non-living.
Answer:
Virus

2. Who proposed Five Kingdom classification?
Answer:
R.H.Whittakar

3. Branch of biology which help to know about correct position of living organism.
Answer:
Taxonomy

4. What helps to understand life of the living organisms lived in past.
Answer:
Fossils

5. Name the missing connecting link between Reptiles and Birds.
Answer:
Archaeopteryx

6. Bacteria helps for nitrogen fixation.
Answer:
Rhizobium

7. Name the causal organism of Diphtheria.
Answer:
Coryne bacterium diphtheria

8. Name the causal organism of disease Pneumonia.
Answer:
Diplococcus pneumoniae

9. Living fossil is?
Answer:
Archaebacteria

10. Bacteria which obtain energy from H2S or S is called as.
Answer:
Sulphur bacteria

Students get through the MP Board Class 11th Biology Important Questions Chapter 22 Chemical Coordination and Integration which are most likely to be asked in the exam.

MP Board Class 11th Biology Important Questions Chapter 22 Chemical Coordination and Integration

Chemical Coordination and Integration Class 11 Important Questions Very Short Answer Type

Question 1.
Which hormone is known as emergency hormone? It is secreted by which gland?
Answer:
Adrenal medulla secretes adrenaline epinephrine which is known as emergency hormone, as it has the capacity to stand in acute emergencies.

Question 2.
Name the diseases caused by hyposecretion of thyroxin.
Answer:
Cretinism, Goitre, Hashimoto’s disease, Myxedema.

Question 3.
Give chemical nature of hormones.
Answer:
Hormones can be divided into three categories :

1. Steroid hormones : Aldosterone, Cortisone, Progesterone, Testosterone.
2. Amino acid: Thyroxine and Epinephrin.
3. Peptide and Protein hormone: Calcitonin, Parathormone, Insulin, Glucagon.

Question 4.
Name the two hormones secreted by the anterior lobe of the pituitary gland.
Answer:

1.  Thyroid-stimulating hormones (T.S.H.)
2. Growth stimulating hormone (G.S.H.)

Question 5.
Name the endocrine part of pancreas and also name the hormone secreted by them.
Answer:
The endocrine part of the pancreas is islets of Langerhans, this part secretes a hormone known as insulin.

Question 6.
Which hormone is known as delivery hormone and why?
Answer:
The hormone oxytocin is known as delivery hormone it helps in the delivery by contracting unstriated muscles of the uterus and bring it in normal position after delivery.

Question 7.
Name the endocrine glands found in mammal.
Answer:
Following endocrine glands are found in human :

• Pituitary,
• Thyroid,
• Parathyroid,
• Adrenalin,
• Thymus,
• Pancreas,
• Gonads.

Question 8.
Where are the progesterone and relaxin hormones formed? Give their function.
Answer:
Progesterone hormone is produced by the corpus luteum. It helps in development of mammary gland and attachment of embryo to the wall of uterus.Placenta of the embryo secretes relaxin during pregnancy. At the time of childbirth, it relaxes the muscles of pelvis so that the vaginal passage may widen and the child may come out easily.

Question 9.
Name the hormone responsible for growth in human.
Answer:
Somatotrophic hormone (STH) secreted by the anterior lobe of pituitary gland is responsible for growth in human. It is also called as growth hormone.

Question 10.
Explain function of FSH in brief. (NCERT)
Answer:
Follicle stimulating hormone (FSH) stimulates the growth of the graffian follicle and secretion of estrogen hormone by the follicle cells in female, where as in male it stimulates the process of spermatogenesis. Due to its action on both the male and female gametes formation, F.S.H. is also referred as gametokinetic factor.

Question 11.
What is osteitis fibrosa cystic?
Answer:
Hypersecretion of parathormone causes Osteitis fibrosa cystica disease. Quantity of Ca⁺⁺ increases in the blood and urine. More calcium collection occurs in the bones.

Chemical Coordination and Integration Class 11 Important Questions Short Answer Type

Question 1.
Name the glands secreting the following hormones :
(i) Thyroxine,
(ii) Insulin,
(iii) Adrenalin and
(iv) Oestrogen,
(v) Oxytocin.
Or,
Give the source and functions of the following hormones :
(i) Thyroxine,
(ii) Insulin,
(iii) Adrenalin,
(iv) Oestrogen,
(v) Oxytocin.
Answer:

Question 2.
Show the effect of hyperactivity of thyroid hormone on human beings.
Answer:
Following are the symptoms of hyperactivity :
(i) Increased metabolic rate, i.e., higher body temperature and high heart rate and restlessness.
(ii) Excessive loss of Ca⁺⁺ and phosphorus from bones or osteoporosis.
(iii) Protruding eyeballs.
(iv) Excessive perspiration.
(v) Excessive hunger but loss of weight.
(vi) Man becomes irritative in nature.

Question 3.
Describe the mechanism of hormone action.
Answer:
Action of hormones takes place by the following two methods :
1. At plasma membrane level: Most of the hormones (proteins) are binded with cell membrane and induce the activity of adenyl cyclase enzyme. This enzyme hydrolyses ATP molecules of the cytoplasm. Hydrolysis of ATP affects cellular metabolism in many ways.

2. At gene level after synthesizing protein: Few hormone (steroids) after reaching the nucleus of the target cell activate the inactive genes or inactivate the active genes. This activity of hormones also affects mRNA synthesis. This mRNA is responsible for the synthesis of proteins and enzyme and thus affects the metabolic activities and growth, structure and development of cell.

Question 4.
Describe the name and significance of hormones secreted by parathyroid gland.
Answer:
Parathyroid gland secretes a hormone known as parathormone.
Significance :
(i) This hormone increases the absorption of Ca⁺⁺ in the walls of intestine and renal tubules.

(ii) It helps in muscle contraction, heart beating and formation of bones.
The deficient secretion of parathormone will cause parathyroid tetany. The deficiency of parathormone during childhood causes stunted growth of teeth, bones and brain. The hypersecretion of this hormone causes osteoporosis, hypercalcaemia and kidney stone like diseases.

Question 5.
Write the name of cells that secrete insulin. Also write the functions of insulin hormone.
Answer:
Insulin is proteinaceous hormone which is secreted by β- cells of islet of langerhans in response to higher levels of glucose and amino acids in the blood.
The chief functions of this hormone are as follows :

1. It controls the amount of sugar in blood and converts glucose into glycogen in liver cells.
2. Conversion of glucose to fatty acids and formation of adipose tissue.
3. Reduction, in the breakdown and oxidation of fat.
4. Absorption of amino acids by the cells and synthesis of proteins from them.

Question 6.
Define following : (NCERT)
(a) Exocrine gland,
(b) Endocrine gland,
(c) Hormone.
Answer:
(a) Exocrine glands: The glands which are duct containing and secrete their secretion into the duct, which cany them to the body surface or on the cavities of the body part are called as exocrine glands, e.g., salivary glands, sweat glands etc.

(b) Endocrine glands: Ductless glands are called as endocrine glands. They secrete their secretion directly into the blood, e.g., Thyroid, Pituitary gland.

(c) Hormones: Hormones are chemically proteins or steroids secreted by the endocrine glands in limited quantity directly into the blood and transferred to some other parts where their physiological effect is observed.

Question 7.
What is pheromones?
Answer:
The term pheromones is used for the first time by Karlson and Butenandt in 1959. It is a chemical secreted by exocrine gland similar to that of hormones. It is also known as ectohormone e.g., female silk insect secretes a pheromone known as bombykol or gyplure which is meant for attraction of male silk insects. Social insects like ant, termite and honeybees are collected on a place due to these pheromones. Pheromones can transmit informations very fastly and distantly.

Question 8.
What are sex hormones? Describe about any two sex hormones.
Answer:
Sex hormones: Hormones which are responsible for sexual activities and regu¬lates the development of secondary sex characters are called as sex hormones. Androgen is the male and oestrogen, progesterone and relaxin are the female hormones.

1. Oestrogen hormone: It is secreted by ovary. Small quantities of this hormone is also secreted by adrenal glands and placenta. This hormone is responsible for development of secondary sexual characters. It stimulates the development of secondary sex organs like uterus, fallopian tubes, ducts of mammary glands and external sex characters like high pitch voice, pattern of distribution of body hairs in the female during puberty.

2. Testosterone: It is a steroid hormone secreted by interstitial cells of Leydig’s cell and also from Sertoli cells. Interstitial cells are not present in the testes of a child but they are present in the testes of newborn infants and also in the testes of adults after puberty. Its production dwindles rapidly beyond the age of 40 and almost zero by the age of 80.

Question 9.
Give examples of following : (NCERT)
(a) Hyperglycemic and Hypoglycemic hormone.
(b) Hypercalcemic hormone.
(c) Gonadotrophic hormone.
(d) Progestational hormone.
(e) Blood pressure lowering hormone.
(f) Androgen and Estrogen.
Answer:
(a) Glucagon and insulin.
(b) Parathormone.
(c) Luteinizing hormone (LH) and follicle stimulating hormone.
(d) Progesteron.
(e) Atrial natriuretic factor (ANF).
(f) Testosterone and androsterone are collectively called as androgen. Estrogen is secreted by the ovary.

Question 10.
What do you understand by suiciding of thyroid gland (Hashimoto’s disease)?
Answer:
Hashimoto’s disease : When medicines are provided for removing the effects produced due to the deficiency of thyroxine hormone, functioning like a foreign substance, then antibodies are synthesized in the body. These antibodies destroys the thyroid gland. The disease produced due to this condition is called as Hashimoto’s disease. It is also called as the suicide of thyroid gland as it is destroyed.

Question 11.
Write differences between following :
(a) Hormone and Enzyme.
(b) Nervous and Endocrinal.
Answer:
(a) Differences between Hormone and Enzyme

(b) Differences between Nervous and Endocrinal co-ordination

Question 12.
Describe various abnormalities of adrenal cortex in brief.
Answer:
Following are the abnormalities of adrenal cortex :
1. Addison’s disease: Insufficiency of glucocorticoid leads to Addison’s Disease characterised by shock, reduced blood pressure, muscular weakness, digestive disturbances, high level of urea in the blood and elevated body temperature. This disease may be also caused due to the deficiency of mineralocorticoids. Symptoms also include low blood sugar, low plasma sodium ions, high plasma potassium ions and increased urinary sodium ions.

2. Hypoglycemia: It is caused due to insufficiency of glucocorticoid. In this disease activities of brain, liver, and heart muscle decreases. Temperature of the body decreases.

3. Conn’s disease: It is caused due to insufficiency of mineralocorticoid. In this disease muscles fails to function due to defect in nerves, and patient dies.

4. Cushing syndrome: Hypersecretion of cortisol from the adrenal cortex due to a tumor of the gland leads to Cushing’s disease or Cushing’s syndrome characterized by hyperglycemia i.e. high blood sugar, increased deposition of glycogen in the liver, increased protein catabolism, appearance of sugar in the urine,’obesity, wasting of limb muscles, disorder of skin and bones, hypertension, rise in plasma Na⁺, fall in plasma K⁺ and retention of water and sodium chloride in the body.

5. Adrenal virilism: Sex steroids influence the functioning of sex organs and development of accessory sex characters. The over production of sex corticoids produces male-type secondary sexual characters such as growing of beards, moustaches and developing male voice in women. This disease is called adrenal virilism.

Question 13.
(1) Which cells of testis secrete male sex hormone?
(2) Why L.H. is called as interstitial stimulating hormone?
Answer:
1. Male sex hormone are produced by the Ley dig’s cells of the testis which are found surrounding the seminiferous tubules.
2. L.H. is called as I.C.S.H. because it induces Leydig’s cells or interstitial cells to secrete testosterone hormone.

Question 14.
Give important functions of testosterone hormone.
Answer:

• It induces development of secondary sexual character in male.
• It induces development of external sexual characters, such as growth of beard, moustaches and development of hairs in hand and legs. It also helps in development of heavy and low voice in man.
• It induces production of sperms in the testis.
• It effects development of tissues in the body.

Question 15.
Name the endocrine glands which secretes protein containing hormone.
Answer:
Following endocrine glands secrete protein containing hormones :

Question 16.
Write the names of hormones related with the different functions like :
(i) Softening of pelvic ligaments at the time of child-birth.
(ii) Expulsion of milk from mammary glands, just after the child-birth.
(iii) Stimulates gametogenesis in male and female.
Answer:
(i) Relaxin.
(ii) Prolactin or Lactogenic or Luteio Tropic Hormone (LTH) and Oxytocin.
(iii) Follicle Stimulating Hormone (FSH).

Question 17.
Draw labelled diagram showing location of various endocrine glands in human body. (NCERT)
Answer:

Question 18.
What is emergency hormone ? How does it help us to protect ourself from emergency condition ?
Answer:
Adrenalin or Epinephrine hormone is secreted by the medulla part of the adrenal gland. Adrenalin hormone is a derivative of tyrosine. Chromaffin cells secrete about 80% adrenalin hormone. This hormone effects all the organs effected by autonomous nervous system.

It is also known as emergency hormone as it is used as heart stimulant in acute emergencies. It is secreted in proportional to the stimulus through the central nervous system. Under the conditions of stimulus such as cold, heat, drugs and emotional excitement, the secretion of adrenalin is greatly increased. In circumstances of great stress, strain and emotional upheaval, the body requires additional energy in hurry. Adrenalin accordingly increases the conversion of glycogen to glucose and thus provides quickly available energy.

As it also increases blood flow, the available glucose may quickly go where it is needed. It dilates the blood vessels in the heart and skeletal muscles, thus decreasing the peripheral resistance and permitting a copious flow of blood to meet the needs of fight and flight.

Question 19.
Name the Endocrine glands from which following hormones are secreted. Give functions of them :
1. Parathormone,
2. Cortisone,
3. Somatotropic hormone,
4. Melatonin.
Answer:

Chemical Coordination and Integration Class 11 Important Questions LongAnswer Type

Question 1.
Name the hormones secreted by following : (NCERT)
(a) Hypothalamus,
(b) Pituitary gland,
(c) Thyroid,
(d) Parathyroid,
(e) Adrenal gland,
(f) Pancreas,
(g) Testis,
(h) Ovary,
(i) Thymus,
(j) Atrium,
(k) Kidney,
(l) Gastrointestinal track.
Answer:
(a) Hypothalamus: Thyrotropin Releasing Hormone (TRH), Adrenocorticotro- phin Releasing Hormone (ARH), Gonadotrophin Releasing Hormone (GRH), Prolactin Re¬leasing Hormone (PRH), Somatotropin Releasing Hormone (SRH), Melanocyte Releasing Hormone (MRH).

(b) Pituitary gland: Somatotrophic hormone (STH), Thyroid stimulating hormone (TSH), Lactogenic hormone (LTH), Adrenocorticotrophic hormone (ACTH), Gonadotrophic hormone (FSH, LH Or ICSH), Melanocyte stimulating hormone (MSH), Vasopressin, Oxytocin.

(c) Thyroid: Thyroxine, Thyrocalcitonin ‘
(d) Parathyroid: Parathormone
(e) Adrenal gland : Mineralocorticoid (aldosterone), Glucocorticoid, Sex hormones (Androgen, Estrogen), Adrenalin, Nor adrenalin.
(f) Pancreas : (islets of Langerhans): Insulin, Glucagon.
(g) Testis : Testosterone, Andosterone.
(h) Ovary : Estrogen, Progesterone.
(i) Thymus: Thymosin.
(j) Atrium : Atrial Netriuretic factor (ANF).
(k) Kidney: Renin, Erythrogenin.
(l) Gastrointestinal track : (Mucosa gland of alimentary canal): Gastrin, secretin, pancreozymins, cholecystokinin, enterocrinin, enterogastrone.

Question 2.
Write short note on functions of following hormones :
(a) Parathormone,
(b) Thyroxin hormone,
(c) Thymosin,
(d) Androgen,
(e) Estrogen,
(f) Insulin and glucagon.
Answer:
(a) Parathormone: Parathyroid gland secretes a hormone known as parathormone.
Significance :
(i) This hormone increases the absorption of Ca⁺⁺ in the walls of intestine and renal tubules.

(ii) It helps in muscle contraction, heart beating and formation of bones.
The deficient secretion of parathormone will cause parathyroid tetany. The deficiency of parathormone during childhood causes stunted growth of teeth, bones and brain. The hypersecretion of this hormone causes osteoporosis, hypercalcaemia and kidney stone like diseases.

(b) Thyroxin hormone:
Thyroid Gland:
Origin: Thyroid gland develops from the endoderm of the embryo.

Location: Thyroid gland is the largest endocrine gland of the body which is located on the ventral side of the neck just below the larynx. It surrounds the front of the larynx and upper part of the trachea in the neck. It has two lobes on either side of trachea.

Structure: Thyroid gland is a pink coloured, H-shaped, bilobed gland, largest gland of the body. Their lobes are connected by an isthmus. In normal healthy person, its weight is about 25 gms, it is larger in female than in male. Thyroid is profusely supplied with blood vessels. The gland consists of large number of small closed follicles or acini of about 200 μ in diameter. Each follicle is lined by a secretory epithelium of cuboidal or low columnar type.

These follicles are held together by areolar tissue. Each follicle contains a clear viscid proteinaceous amber coloured colloid which normally comprises the greater part of the thyroid mass. The colloid consists mainly of iodinated thyroglobulin. In polybreeders like human beings the gland functions almost uniformly but in seasonal breeders the gland is active at one stage and inactive at the other.

Hormones of Thyroid Gland :
1. Thyroid gland secretes three hormones :

1. Thyroxin or tetraidothyronine (T4),
2. Triiodothyronine (T3) and
3. Thyrocalcitonin (TCT).

1. Thyroxine: Thyroxine hormone contains about 60% of iodine.
Functions of thyroxine:

• Thyroxine hormone regulates approximately all types of metabolic reactions of the body.
• It effects all energy releasing oxidation processes.
• It controls the temperature of the body.
• It controls the amount of intracellular substances of the tissue.
• It maintains the normal stimulus of the cardiac muscles.

2. Tri-iodothyronine: It functions like thyroxine but more rapidly.
3. Thyrocalcitonin: It regulates the amount of Ca in urine and blood.

(c) Thymosin: It stimulates the proliferation of lymphocytes and also restores cell-mediated immunological functions such as the ability to reject first or second set skin grafts.

(d) Androgen: It includes Testosterone and Androsterone. Both Androsterone and Testosterone are secreted by the interstitial cells. It induces development of secondary sexual characters in male human.

(e) Estrogen:
Sex hormones: Hormones which are responsible for sexual activities and regu¬lates the development of secondary sex characters are called as sex hormones. Androgen is the male and oestrogen, progesterone and relaxin are the female hormones.

1. Oestrogen hormone: It is secreted by ovary. Small quantities of this hormone is also secreted by adrenal glands and placenta. This hormone is responsible for development of secondary sexual characters. It stimulates the development of secondary sex organs like uterus, fallopian tubes, ducts of mammary glands and external sex characters like high pitch voice, pattern of distribution of body hairs in the female during puberty.

2. Testosterone: It is a steroid hormone secreted by interstitial cells of Leydig’s cell and also from Sertoli cells. Interstitial cells are not present in the testes of a child but they are present in the testes of newborn infants and also in the testes of adults after puberty. Its production dwindles rapidly beyond the age of 40 and almost zero by the age of 80.

(f) Insulin and Glucagon: Insulin hormone is secreted by the /?-cells of islets of Langerhans. Its main function is to regulated amount of glucose in the blood by converting excess glucose into glycogen by glycogenesis process in the liver for storage. Glucagon hormone is secreted by the a-cells of islets of Langerhans. It stimulates glycogenolysis, thus glucose is releases into the blood from the liver when there is low concentration of glucose in the blood.

Question 3.
Describe the structure and position of pituitary gland and write the name and functions of hormones secreted by them.
Or,
Where is pituitary gland situated? Write the name of two hormones secreted by posterior lobe of pituitary gland.
Or,
Why pituitary gland is called master gland? Write its structure and hormones.
Answer:
Pituitary gland: It is a small and rounded gland which is found on the dorsal surface of brain just behind the optic chiasma and is closed within the cavity of celatersica.
It is known as hypo-physis. It is attached by a stalk with the infundibulum on the mid part of dorsal surface of the brain. It is the regulatory centre of other glands hence, it is also called as the master gland of the body. It is made up of following three parts :

1. Fore lobe,
2. Mid lobe and
3. Hind lobe.

Hormones of fore lobe and their functions :
1. Somatotrophic hormones (STH): It controls the growth of the body. It is respon¬sible for the development of bones.

2. Thyrotrophic hormones (TSH): This hormone is responsible for the secre tion of thyroid gland.

3. Adrenocorticotrophic hormone (ACTH): It is secreted by the anterior lobe of pituitary gland to control the synthesis and secretion of hormones from adrenal cortex.

4. Follicle stimulating hormones (FSH): In male, FSH stimulates growth of the sperms in the testis and egg in the ovary of female.

5. Luteinizing hormones (LH): This hormone brings about ovulation, secretion of oestrogens and progesterone formation of corpus luteum in female and stimulates the interstitial cells of the testis to secrete testoster¬one in the male.

6. Prolactin or lactogenic or luteotrophic hormone (LTH): This hormone promotes mammary growth and lactation and maintains the corpus luteum and causes it to become actively secretory.
Neurotrophic hormone or hormones of posterior lobe :

• Vasopressin or antidiuretic hormone: It causes increased reabsorption of water in the kidney tubule also helps to maintain the arterial blood pressure within the normal range.
• Oxytocin hormone: It stimulates uterine contraction during childbirth and cause milk ejection from the mammary glands during sucking.

Question 4.
Describe the functions of hormones secreted by thyroid glands.
Or,
Write the position of thyroid gland. Write its function.
Answer: Thyroid Gland:
Origin: Thyroid gland develops from the endoderm of the embryo.

Location: Thyroid gland is the largest endocrine gland of the body which is located on the ventral side of the neck just below the larynx. It surrounds the front of the larynx and upper part of the trachea in the neck. It has two lobes on either side of trachea.

Structure: Thyroid gland is a pink coloured, H-shaped, bilobed gland, largest gland of the body. Their lobes are connected by an isthmus. In normal healthy person, its weight is about 25 gms, it is larger in female than in male. Thyroid is profusely supplied with blood vessels. The gland consists of large number of small closed follicles or acini of about 200 μ in diameter. Each follicle is lined by a secretory epithelium of cuboidal or low columnar type.

These follicles are held together by areolar tissue. Each follicle contains a clear viscid proteinaceous amber coloured colloid which normally comprises the greater part of the thyroid mass. The colloid consists mainly of iodinated thyroglobulin. In polybreeders like human beings the gland functions almost uniformly but in seasonal breeders the gland is active at one stage and inactive at the other.

Hormones of Thyroid Gland :
1. Thyroid gland secretes three hormones :

1. Thyroxin or tetraiodothyronine (T4),
2. Triiodothyronine (T3) and
3. Thyrocalcitonin (TCT).

1. Thyroxine: Thyroxine hormone contains about 60% of iodine.
Functions of thyroxine:

• Thyroxine hormone regulates approximately all types of metabolic reactions of the body.
• It effects all energy releasing oxidation processes.
• It controls the temperature of the body.
• It controls the amount of intracellular substances of the tissue.
• It maintains the normal stimulus of the cardiac muscles.

2. Tri-iodothyronine: It functions like thyroxine but more rapidly.
3. Thyrocalcitonin: It regulates the amount of Ca in urine and blood.

Question 5.
Write down the names and significance of parathyroid gland hormones.
Answer:
The hormones released by parathyroid are called parathormone.
Functions: It controls Ca²⁺ and PO₄^-3 ” in blood along with muscle contraction, heartbeat, bone formation, etc.
Hyposecretion: Due to its deficiency bones, teeth do not develop properly.
Hypersecretion: Due to its overproduction osteoporosis, hypercalcimia, stone in kidney, calcitonin diseases occur.

Question 6.
What are ductless glands? Describe Thyroid, Adrenal, Ovary and Pancreas.
Answer:
Ductless gland: The glands which secrete, their secretion directly into the blood circulatory system as they do not have duct are called as ductless endocrine glands. The substance secreted by them are called as hormones which are transported to required part of the body through blood.

1.Thyroid: This gland is a soft bibbed structure formed of glandular tissue. It is situated in front of trachea immediately below the larynx. The two lobes of the gland are connected with each other by a narrow connective tissue structure called isthmus. The hormone secreted by it is Thyroxine. It is a colloidal substance containing much iodine. The whole hormone is C₁₅H₁₀O₄N₁₄.

2. Adrenal: These glands are situated very close to the kidneys; therefore, they are called adrenal or suprarenal glands. The outer part of the glands is called cortex and inner medulla. The origin and function of both these parts are different.

(i) Cortex: It originates from mesodermal cells and is enclosed in a capsule. The secretion of cortex are very important for life. These substances control carbohydrate me¬tabolism, amount of salts in blood, regulate the volume of blood, control the sexual maturity and create the resistance from the diseases in the body of the animal.

It produces about 20 steroid compounds which are called cortisones, the important among which are following :
(a) Corticosterone or Glucocorticoid,
(b) Cortisone,
(c) Mineralocorticoid,
(d) Sex-hormone.

(ii) Medulla: It is present on the inner side of adrenal and surrounded by the cortex. It produces two hormones
(a) Adrenalin,
(b) Noradrenalin. Adrenalin is also called as emergency gland.
3. Ovary: In female one pair of ovaries are found. Three types of hormones are secreted by them :

1. Estrogen,
2. Progesterone,
3. Relaxin.

4. Pancreas: Pancreas functions both as exocrine and endocrine. The organ has certain specialized cells which are histologically different from the rest of the pancreatic tissue. These cells are endocrine in function and was discovered by Langerhans, therefore, they are known as islets of Langerhans. The islets of Langerhans in the pancreas secrete the polypeptide hormone, glucagon and the protein hormone, insulin.

They are concerned with the regulation of intermediary metabolism. Glucagon elevates the blood glucose by stimu-lating hepatic glycogenolysis. They maintain the blood glucose level during starvation.

Chemical Coordination and Integration Class 11 Important Questions Objective Type

1. Choose the correct answers:

Question 1.
Which one of the following pairs is the matching pair of the part and the hormone it secretes :
(a) Thyroid-Epinephrin
(b) Alpha cells of pancreas-Glucagon
(c) Anterior pituitary-Adrenalin
(d) Stomach epithelium-Secretin.
Answer:
(b) Alpha cells of pancreas-Glucagon

Question 2.
Failure of insulin production results in :
(a) Addison’s disease
(b) Cushing’s disease
(c) Diabetes insipidus
(d) Diabetes mellitus.
Answer:
(d) Diabetes mellitus.

Question 3.
Oestrogens are the hormones produced by :
(a) Testes
(b) Ovary
(c) Pituitary
(d) Adrenal cortex.
Answer:
(b) Ovary

Question 4.
Development of secondary sexual characters in females are controlled by:
(a) Oestrogen
(b) Oxytocin
(c) Progesterone
(d) Androgen.
Answer:
(a) Oestrogen

Question 5.
Which hormone is secreted more in dark condition:
(a) Insulin
(b) Adrenalin
(c) Thyroxine
(d) Melatonin.
Answer:
(d) Melatonin.

Question 6.
Continued secretion of milk is maintained by :
(a) Pituitary
(b) Thyroid
(c) Pancreas
(d) Adrenal.
Answer:
(a) Pituitary

Question 7.
Progesterone hormone is secreted by :
(a) Corpus luteum
(b) Corpus callosum
(c) Corpus uteri
(d) Corpus albicans.
Answer:
(a) Corpus luteum

Question 8.
If adrenal cortex function is impaired, it results in decreased concentration of one of the following in the blood: (MP PMT 1988)
(a) Ammonium salts
(b) Sodium salts
(c) Glucose
(d) Calcium salts.
Answer:
(b) Sodium salts

Question 9.
Diabetes insipidus is caused due to the deficiency of :
(a) Oxytocin
(b) Insulin
(c) Vasopressin
(d) Glucagon.
Answer:
(c) Vasopressin

Question 10.
Adrenal glands are found located in abdominal cavity in close association with:
(a) Testes
(b) Spleen
(c) Liver
(d) Kidneys.
Answer:
(d) Kidneys.

Question 11.
The male hormone, testosterone is secreted by:
(a) Sperms
(b) Seminiferous tubules
(c) Prostrate glands
(d) Interstitial cells of testes.
Answer:
(d) Interstitial cells of testes.

Question 12.
The name of hormone secreted by the ovary which facilitates growth of ovarian follicle is :
(a) Progesterone
(b) LH
(c) FSH
(d) Estradiol.
Answer:
(d) Estradiol.

Question 13.
Which of the endocrine gland is mainly concerned with immunity in human :
(a) Parathyroid gland
(b) Adrenal gland
(c) Thymus gland
(d) Posterior pituitary gland.

Answer:
(c) Thymus gland

Question 14.
Emergency hormone ¡s:
(a) Aldostrerone
(b) Pentathromone
(c) Adrenaline
(d) Thyroxin.
Answer:
(c) Adrenaline

2. Fill in the blanks:

(A)

1. Islets of langerhans are formed in ………….. It secrets ………….. hormone.
Answer:
Pancrease, insulin,

2. ………….. is an antidiuretic hormone.
Answer:
Vasopressin,

3. Hyposecretion of somatotropin results in ………….. whereas its hypersecretion results …………..
Answer:
Dwarfism, Gigantism,

4. Deficiency of insulin hormone causes ………….. disease.
Answer:
Diabetes,

5. Goitre disease is caused due to deficiency of ………….. .
Answer:
Iodine,

6. Progesterone hormone is secreted by ………….. .
Answer:
Corpus luteum,

7. Adrenalin hormone increases ………….. and ………….. .
Answer:
Heart beat, blood pressure

8. Melatonin hormone is secreted by ………….. .
Answer:
Pituitary gland,

9. Human became dwarf due to deficiency of ………….. hormone.
Answer:
Thyroxin.

(B)

Answer:
1. Pituitary gland,
2. Thyroid gland,
3. Adrenal gland,
4. Gonads (Testis or ovary),
5. Hypothalamus.

3. Match the following:

(A)

Answer:
1. (b)Thyroid
2. (d) Parathyroid.
3.  (a) Hypothalamus
4. (c) Pituitary gland.

(B)

Answer:
1. (c) Thyroxin
2. (d) Milk secretion
3. (e) Progesterone.
4. (a) Testosterone
5. (b) Somatotropin

(C)

Answer:
1. (b) Pituitary gland
2. (a) Delivery hormone
3. (e) Thyroid.
4. (d) Hypothalamus
5. (c) LH.

4. Answer in one word:

1. Name the part of brain in which pituitary gland is found.
Answer:
Thalamus,

2. Name the hormone which control the amount of Ca in blood.
Answer:
Parathyroid hormone,

3. Name the largest gland of our body.
Answer:
Pituitary gland,

4. Name the cell that secrets testosterone hormone.
Answer:
Interstitial cells,

5. Name the gland of man from which vasopressin hormone is secreted.
Answer:
Hypothalamus,

6. Name the hormone which stimulates the secretion of milk.
Answer:
Prolactin hormone,

7. Which hormone is known as delivery hormone.
Answer:
Relaxin,

8. Write the name of any two hormones secreted by the anterior part of pituitary gland.
Answer:
T.S.H. and S.T.H,

9. What we called the ratio of volume of air inspired and expired during respiration.
Answer:
Vital capacity.

Students who wish to prepare the English Subject can rely on the MP Board Solutions for Class 6 English Essay Writing Questions and Answers prevailing. Become perfect with the concepts of Class 6 English Essay Writing Questions and Answers, Essay Writing, Summary, Notes, Guide, Pdf, by preparing you can score highest grade in your exams. Here, You Can Download MP Board Class 6 English Solutions. Detailed Solutions are provided to the concepts by experts keeping in mind the latest edition textbooks and syllabus.

MP Board Class 6th General English Essay Writing

Ace up your preparation by referring to the Madhya Pradesh State Board Solutions for Class 6 Essay Writing Questions and Answers and learn all the topics within. Click on the topic you want to prepare from the Class 6 English and prepare it easily. You can understand your strengths and weaknesses by learining the Questions and Answers in MP Board Solutions for Class 6 English PDF.

The Cow (द काउ)
गाय

1. The cow is a pet animal.
2. She is four footed animal.
3. She has two eyes and two horns.
4. She has a long tail and two big ears.
5. She eats grass, leaves, corn and hay.
6. She gives us milk.
7. She gives us calves.
8. Her calves are used for agriculture.
9. Curd, butter and ghee is made from her milk.
10. Hindus worship the cow.
11. We call her ‘Gau Mata’.

Meanings of Difficult Words (कठिन शब्दों के अर्थ) :
Pet (पैट) = पालतू, animal (एनिमल) = जानवर, four footed (फोर फुटेड) = चौपाया, eyes (आइज़) = आँखें, horns (हॉर्स) = सींग, long (लौंग) = लम्बा, tail (टेल) = पूँछ, big (बिग) = बड़ा, ears (ईयर्स) = कान, eat (ईट) = खाना, grass (ग्रास) = घास, leaves (लीव्ज़) = पत्तियाँ, corn (कॉर्न) = अनाज, hay (हे) = भूसा, give (गिव) = देना, milk (मिल्क) = दूध, calves (काव्ज़) = बछड़े, used (यूज्ड) = प्रयोग किया जाता है, agriculture (एग्रीकल्चर) = कृषि, curd (कर्ड) = दही, butter (बटर) = मक्खन, ghee (घी) = घी, Hindu (हिन्दू) = हिन्दू, worship (वर्शिप) = पूजा करते हैं, Gau Mata (गऊ माता) = गऊ माता।

The Dog (द डॉग)
कुत्ता

1. The dog is a pet animal.
2. It is found all over the world.
3. It is found in many colors such as black, white, brown and black and white.
4. It has four legs, a tail, two eyes and two ears.
5. Its has sharp teeth also.
6. It eats bread, milk and meat.
7. It watches its master’s house.
8. It barks when its sees a stranger.
9. The dog is a good friend of man.
10. It is very useful and faithful animal.

Meanings of Difficult Words (कठिन शब्दों के अर्थ) :
Found (फउण्ड) = पाया जाता है, world (वर्ल्ड) = विश्व, संसार, many (मैनी) = बहुत, colors (कलर्स) = रंगों, black (ब्लैक) = काला, white (व्हाइट) = सफेद, brown (ब्राउन) = कत्थई, black and white (ब्लैक एण्ड ह्वाइट) = चितकबरा, sharp (शार्प) = तेज, bread (ब्रेड) = रोटी, meat (मीट) = माँस, watch (वॉच) = रखवाली करना, master (मास्टर) = मालिक, house (हाउस) = घर, bark (बार्क) = भौंकना, when (व्हेन) = जब, see (सी) = देखना, stranger (स्ट्रेन्जर) = अजनबी, friend (फ्रेण्ड) = मित्र, useful (यूज़फुल) = उपयोगी, faithful (फेथफुल) = स्वामी भक्त।

My School (माई स्कूल)
मेरा स्कूल

1. I read in Sarafa School, Lashkar.
2. Mr. P.C. Dubey is my Head Master.
3. There are five hundred students in my school.
4. There are nine teachers in my school.
5. All teachers are very hard working.
6. My school has a beautiful building.
7. There are nine rooms and an office.
8. There is a big playground also.
9. There is a big library in my school.
10. The result of my school is always very good.
11. like my school very much.

Meanings of Difficult Words (कठिन शब्दों के अर्थ) :
Head Master (हैड मास्टर) = प्रधान अध्यापक, five hundred (फाइव हण्ड्रेड) = पाँच सौ, hard working (हार्ड वर्किंग) = कठिन परिश्रमी, beautiful (ब्युटीफुल) = सुन्दर, building (बिल्डिंग) = भवन, rooms (रूम्स) = कमरे, office (ऑफिस) = कार्यालय, playground (प्ले-ग्राउण्ड) = खेल का मैदान, big (बिग) = बड़ी, library (लायब्रेरी) = पुस्तकालय, result (रिज़ल्ट) = परिणाम, always (ऑलवेज़) = हमेशा, like (लाइक) = पसन्द करना।

The Postman (द पोस्टमैन)
डाकिया

1. The Postman is a government servant.
2. He wears khaki uniform.
3. He goes door to door.
4. He has a leather bag on his shoulder.
5. He delivers letters and money-orders.
6. We all wait for him every day.
7. His duty is very hard.
8. But his pay is very low.
9. We should be kind to him.
10. He must be paid well.

Meanings of Difficult Words (कठिन शब्दों के अर्थ) :
Government (गवर्नमेण्ट) = सरकारी, servant (सर्वेण्ट) = नौकर, wears (वेअर्स) = पहनता है, khaki (खाकी) = खाकी, uniform (यूनीफॉर्म) = वर्दी, door (डोर) = द्वार, leather (लैदर) = चमड़ा, bag बैग = थैला, shoulder (शोल्डर) = कन्धा, delivers (डेलीवर्स) = बाँटता है, letter (लैटर) = पत्र, moneyorder (मनी-ऑडर्र) = धनादेश, wait (वेट) = इन्तजार, every day (एवरी डे) = रोजाना, duty (ड्यूटी) = कर्त्तव्य, hard (हार्ड) = कठिन, but (बट) = किन्तु, pay (पे) = वेतन, low (लो) = कम, नीचा, kind (काइण्ड) = दयालु, well (वैल) = अच्छा

My Daily Life (माई डेली लाइफ)
मेरी दिनचर्या

1. I get up at 5 O’clock in the morning.
2. After attending to nature call I go for a walk.
3. I return and take breakfast.
4. I study from 7 a.m. to 9 a.m.
5. Then I take bath and lunch and go to school.
6. I study at school from 10.30 a.m. to 4:30 p.m.
7. I return home and have tea at 5 p.m.
8. I play games for an hour, then I study for three hours and take dinner at 9:00 p.m.
9. I watch television for an hour.
10. I go to bed at 10 p.m.
11. On Sundays I watch films and serials on T.V. and help my parents in domestic work.

Meanings of Difficult Words (कठिन शब्दों के अर्थ) :
Nature call (नेचर कॉल) = नित्य कर्म, breakfast (ब्रेकफॉस्ट) = सुबह का नाश्ता, lunch (लन्च) = दोपहर का नाश्ता, dinner (डिनर) = रात का भोजन, study (स्टडी) = अध्ययन करना, domestic (डोमेस्टिक) = घरेलू, serials (सीरियल्स) = धारावाहिक।

My Best Friend (माई बेस्ट फ्रेण्ड)
मेरा प्रिय मित्र

1. I have several friends but Ram is my best friend.
2. He is my neighbour and also my classmate.
3. He always stands first in the class.
4. But he is not proud.
5. He always helps his classmates.
6. His father is a businessman and his mother is a teacher.
7. We go to school together and study at home together.
8. He is good at sports and games too.
9. He faces problems boldly.
10. I like him for his qualities and good nature.

Meanings of Difficult Words (कठिन शब्दों के अर्थ) :
Several (सेवरल) = अनेक, neighbour (नेबर) = पड़ोसी, classmate (क्लासमेट), = सहपाठी, proud (प्राउड) = घमण्ड, businessman (बिजेनेसमैन) = व्यापारी, face (फेस) = सामना करना, boldly (बोल्डली) = हिम्मत से, qualities (क्वालिटीज़) = अच्छाइयाँ, nature (नेचर) = व्यवहार।

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Students who wish to prepare the English Subject can rely on the MP Board Solutions for Class 6 English Grammar Questions and Answers prevailing. Become perfect with the concepts of Class 6 English Grammar Questions and Answers, Grammar, Summary, Notes, Guide, Pdf, by preparing you can score highest grade in your exams. Here, You Can Download MP Board Class 6 English Solutions. Detailed Solutions are provided to the concepts by experts keeping in mind the latest edition textbooks and syllabus.

MP Board Class 6th General English Grammar

Ace up your preparation by referring to the Madhya Pradesh State Board Solutions for Class 6 Grammar Questions and Answers and learn all the topics within. Click on the topic you want to prepare from the Class 6 English and prepare it easily. You can understand your strengths and weaknesses by learining the Questions and Answers in MP Board Solutions for Class 6 English PDF.

Noun (नाउन)
संज्ञा

परिभाषा :
Noun is the name of a person, place or a thing. As- Ram, Gwalior, Chair.
अर्थात्, किसी व्यक्ति, स्थान या वस्तु के नाम को संज्ञा कहते हैं। जैसे-राम, ग्वालियर, कुर्सी।

भेद-Noun पाँच प्रकार के होते हैं-
1. Common Noun (जाति वाचक संज्ञा) :
जिस शब्द से सम्पूर्ण जाति का बोध हो; जैसे-
Man, boy, girl, cow, dog, postman, teacher, friend आदि।

2. Proper Noun (व्यक्ति वाचक संज्ञा) :
जो शब्द किसी व्यक्ति का नाम, स्थान अथवा वस्तु के नाम का बोध करता हो; जैसे-
Arun, Mohan, Bhopal, Delhi, Ganga, Ramayana, Geeta आदि।

3. Collective Noun (समूह वाचक संज्ञा) :
जिस शब्द से किसी समूह का बोध हो; जैसे-Class, Police, Army, Bunck of keys आदि।

4. Material Noun (धातु वाचक संज्ञा) :
विभिन्न धातुओं अथवा धातु से बनी वस्तुओं के नाम; जैसे-
Silver, gold, iron, steel, golden ring, steel almirah आदि।

5. Abstract Noun (भाव वाचक संज्ञा) :
किसी वस्तु या व्यक्ति का गुण या स्थिति को बताने वाले शब्द जैसे-
Sweetness, childhood, bitterness आदि।

Pronoun (प्रोनाउन)
सर्वनाम

परिभाषा :
Pronoun is a word which is used in place of a noun; as – I, we, you, he आदि।
अर्थात् सर्वनाम वह शब्द है जो किसी संज्ञा के स्थान पर प्रयोग किया जाता हैं। जैसे-मैं, हम तुम, वह आदि।
भेद- Pronoun निम्न प्रकार के होते हैं-

1. Personal Pronoun (व्यक्ति वाचक सर्वनाम) :
जो शब्द किसी व्यक्ति या वस्तु से स्थान पर बोले जोते हैं, वे Personal Pronoun होते हैं; जैसे-
She is a student.
He is my brother.
It is mine.

इन वाक्यों में She, He, It, my, mine को प्रयोग व्यक्ति तथा वस्तु के स्थान पर हुआ है। ये Personal Pronoun हैं।

विशेष : She का प्रयोग स्त्री के लिए, He का प्रयोग पुरुष के लिए तथा It का प्रयोग निर्जीव वस्तु के लिए एकवचन में किया जाता है। They का प्रयोग बहुवचन में इन सभी के लिए किया जाता है।

2. Reflexive Pronoun (निज वाचक सर्वनाम) :
जो सर्वनाम स्वयं के लिए प्रयोग हो; जैसे-
myself, yourself, himself.

3. Demonstrative Pronoun (संकेत वाचक सर्वनाम) :
जो सर्वनाम वस्तु की स्थिति की ओर संकेत करते हो; जैसे-
this, that, those, these आदि।

4. Distributive Pronoun (प्रत्येक वाचक सर्वनाम) :
अलग-अलग वस्तुओं की ओर संकेत करने वाले शब्द Distributive Pronoun कहलाते हैं; जैसे-
each, every, neither, either.

5. Interrogative Pronoun (प्रश्न वाचक सर्वनाम) :
जो शब्द किसी प्रश्न को पूछे और किसी संज्ञा के स्थान पर प्रयोग किए जायें; जैसे-
who, what, whom आदि।

6. Indefinite Pronoun (अनिरचय वाचक सर्वनाम) :
यह अनिश्चितता के लिए प्रयोग होते हैं जैसे-
none, some, many, any आदि।

7. Relative Pronoun (सम्बन्ध वाचक सर्वनाम) :
किसी वस्तु या नाम से सम्बन्ध स्थापित करने के लिए इनका प्रयोग होता है; जैसे-
which, that, whose आदि।

Adjective (एडजेक्टिव)
विशेषण

परिभाषा :
Adjective is a word which qualifies a noun or pronoun. अर्थात् संज्ञा तथा सर्वनाम की विशेषता बतलाने वाले शब्द विशेषण कहलाते हैं; जैसे-

1. Ram is a clever boy.
2. Tea is hot.
3. My pencil is long.

उपर्युक्त वाक्यों में clever, hot तथा long संज्ञा की विशेषता बताते हैं। अतः ये शब्द Adjective (विशेषण) हैं।

कुछ विशेषण (Adjective) इस प्रकार हैं-beautiful (सुन्दर), ugly (बदसूरत), strong (मजबूत), weak (कमजोर), new (नया), old (पुराना), white (सफेद), big (बड़ा), small (छोटा), आदि।

Article (आर्टिकल)
उपपद

Article तीन हैं-

1. a
2. an
3. the.

a तथा an का प्रयोग एकवचन के लिए होता है। the का प्रयोग एकवचन तथा बहुवचन दोनों के लिए होता है।
(1) A का प्रयोग :
Consonant (व्यंजन) से प्रारम्भ होने वाले एकवचन की जातिवाचक संज्ञा के पूर्व होता है। जैसे-
a book, a man, a dog, a cat आदि।

(2) An का प्रयोग :
vowels (a, e, i,.o u) स्वर से प्रारम्भ होने वाले एकवचन की जातिवाचक संज्ञा के पूर्व होता है। जैसे-
An apple, an eye, an inkpot, an orange, an umbrella आदि।

(3) The का प्रयोग :
किसी खास वस्तु, अनोखी वस्तु, नदी, पहाड़, प्रसिद्ध ग्रंथ, अखबार के नाम आदि के पहले होता है। जैसे-
The Sun, The Earth, The Ganga, The Indian Ocean, The Taj, The East आदि।

किसी खास या पूर्व परिचित वस्तु का बोध कराने के लिए भी The का प्रयोग किया जाता है। जैसे-
The girl in blue is my sister.

Verb (वब)
क्रिया

परिभाषा :
A verb denotes an action
अर्थात् जिस शब्द से किसी कार्य का करना या होना पाया जाता है; उसे क्रिया कहते हैं। जैसे-sing, play, write, teach.

क्रिया के भेद :
क्रिया दो प्रकार की होती है-
(1) Main Verb (मुख्य क्रिया)
(2) Helping Verb (सहायक क्रिया)।

1. Main Verb (मुख्य क्रिया) :
कर्ता के द्वारा जो कार्य किया जाता है वह मुख्य क्रिया कहलाती है। जैसे-

1. Ram sings a song.
2. Mohan reads a book.

उपर्युक्त वाक्य में sings तथा reads मुख्य क्रिया हैं।

2. Helping Verb (सहायक क्रिया) :
is, are, am, was, were, has, have, had, will, shall, do, does, did, can, may आदि।
सहायक क्रिया मुख्य क्रिया के साथ मिलकर वाक्य के Tense (काल) को स्पष्ट करती है। जैसे-

1. Ram is going.
2. Sita was singing a song.
3. They will go to Lucknow tomorrow.

उपर्युक्त वाक्यों में (1) वाक्य में is going से स्पष्ट होता है कि वाक्य Present Continuous काल का है। (2) वाक्य में was singing से स्पष्ट हो रहा है कि वाक्य Past Continuous तथा (3) वाक्य में will go से स्पष्ट हो रहा है कि वाक्य Future – Indefinite का है।

Adverb (एडवब)
क्रिया-विशेषण

परिभाषा :
वह शब्द जो विशेषण और दूसरे क्रिया-विशेषण की विशेषता बतलाता है, क्रिया-विशेषण (Adverb) कहलाता है; जैसे-
1. Ram runs quickly.
राम जल्दी दौड़ता है।

2. This is a very sweet mango.
यह बहुत मीठा आम है।

3. He is walking slowly.
वह धीरे-धीरे चल रहा है।

4. You write too slowly.
तुम बहुत धीमे लिखते हो।

उपर्युक्त वाक्यों में quickly ‘runs’ नामक क्रिया की विशेषता बताता है। ‘very’ sweet adjective शब्द की विशेषता बताता है। ‘slowly’ शब्द ‘is walking’ क्रिया की विशेषता बता रहा है और ‘too’ शब्द ‘slowly’ क्रिया विशेषण की विशेषता बताता है। अत: quickly, very, slowly, too क्रिया विशेषण (Adverb) हैं।

अंग्रेजी में 4 प्रकार के Adverbs प्रारम्भिक विद्यार्थियों को याद कर लेने चाहिए।
क्रिया-विशेषण के भेद
1. Adverb of time (समय सूचक) :
Now, then, early late, before, already, Presently, since, ago, soon आदि।

2. Adverb of place (स्थान वाचक) :
Far, near, above, in, below, out, within, without, inside, outside आदि।

3. Adverb of Number (संख्या वाचक) :
Once, twice, thrice, again, always, often, sometimes आदि।

4. Adverb of Quantity (मात्रा वाचक) :
Too, most, fully, rather, quite, very, wholly, partly, so आदि।

The Preposition (द प्रिपोजिशन)
सम्बन्ध सूचक अव्यय

परिभाषा :
सम्बन्ध सूचक अव्यय वे शब्द हैं जो किसी संज्ञा अथवा सर्वनाम से पूर्व प्रयुक्त होकर, उसका सम्बन्ध किसी अन्य संज्ञा या सर्वनाम से स्थापित करते हैं।
Note-
(i) Preposition किसी Noun या Pronoun से पूर्व आता है।
(ii) यदि Preposition Verb के बाद आता है और उसके बाद Noun या Pronoun न आ रहा हो तो वह Adverb होता है, जैसे-
Adverb                                 Preposition
1.Gopal is in.                     Gopal is in the room.
2. The teacher is out.        The teacher is out of the class.