NCERT Exercise Questions //J
1. Name the components of the fonned elements in Ans. Formed elements of blood include the blood
the blood and mention one major function of each corpuscles wh.ich freely float in the plasma. Blood
of them. corpuscles are of following types, each of which is
specialised for a specific function :
, Formed elements Biological function/s 6. What is meant by double circulation? What is its
significance?
A. Erythrocytes or RBCs : • Transportation of 97- Ans. Double circulation involves circulation of blood
99% of 02 as oxyHb. twice through the heart to supply it once to the body.
• Transportation of 23% It is more efficient than single circulation of fishes
of CO2 as carbami- because blood flows at higher pressure and speed
noHb. whicl1 increases the rate of not only nutrient supply
B. Leucocytes or WBCs : to the body tissues but also faster removal of wastes
- Neutrophils : Act as soldiers and eat from them.
upon the microbes by 7. Write the differences between :
phagocytosis. (a) Blood and lymph.
- Basophils : Secrete heparin and
(b) Open and closed system of circulation.
histamine so help in
anticoagulation. (c) Systole and diastole.
- Acidophils : Secrete cytotoxin on (d) P-wave and T-wave.
the microbes and help Ans. (a) Refer Table 3 of chapter 18.
in healing of wounds.
(b) Refer Table 2 of chapter 18.
- Monocytes : Act as scavengers and
remove damaged and (c) Refer Table 13 of cl1apter 18.
dead cells of the body. (d) Refer Table 19 of chapter 18.
- Lymphocytes : Secrete antibodies 8. Describe the evolutionary change in the pattern of
which provide heart among the vertebrates.
immunity against the
Ans. Refer pages 9 and Fig. 11 of d1apter 18.
pathogens.
C. Blood platelets : Secrete thromboplas- 9. Why do we call our heart myogenic?
tin and platelet factors Ans. Because in man, the nodal tissues of the heart (e.g.
at the injuries and S.A. node, A.V. node, Bw1dJe of His and Purkinje
help in blood clotting fibres) whid1 collectively form the conducting system
to prevent excessive of the heart and regulate the heartbeat, are groups
bleeding. of special cardiac muscle fibres.
10. Sino-atrial node is called the pace maker of the
2. What is the importance of plasma proteins? heart. Why?
Ans. (i) Albumins maintain the osmotic pressure of Ans. Because sino-atrial node has highest degree of
blood. rhythmicity and is first to originate the cardiac
(ii) Globulins act as antibodies and provide impulses and determines the rate of heart beat.
immunity. 11. What is the significance of atrio-ventricular node
(iii) Fibrinogen and Prothrombin help in blood and atrio-ventricular bundle in the functioning of
clotting at the injury. the heart?
(iv) Properdin kills many types of bacteria and Ans. Atrio-ventricular node acts as pace-setter and
inactivates viruses. generates the cardiac impulses which are conducted to
the ventricular muscles through the atrio-ventricular
3. Match Colunm I with column II : bundle (also called BundJe of His) and the Purkinje
Column I Colunm II fibres at the speed of 1-4 metre/second.
(a) Eosinophils (i) Coagulation 12. Define a cardiac cycle and cardiac output.
(b) RBC (ii) Universal recipient Ans. (i) Cardiac cycle involves the sequence of events
(c) AB blood group (iii) Resist infection that occur during one heart beat. It is completed
(d) Platelets (iv) Contraction of heart in 0.8 seconds.
(e) Systole (v) Gas transport (ii) Cardiac output is the volume of blood ejected
from the ventricles of heart in one minute. It is
Ans. (a) (iii); (b) (v); (c) (ii); (d) (i); (e) (iv). 5 litres per minute.
4. Why do we consider blood as a connective tissue? 13. Explain heart sounds.
Ans. Because it has large amount of intercellular matrix, Ans. Refer page 15 of chapter 18.
called blood plasma, and a three types of blood 14. Draw a standard ECG and explain the different
corpuscles. segments in it.
5. What is differences between lymph and blood? Ans. Refer page 17-18 and Fig. 19 of cl1apter 18.
Ans. Refer Table 3 of chapter 18.
1. Name the components of the fonned elements in Ans. Formed elements of blood include the blood
the blood and mention one major function of each corpuscles wh.ich freely float in the plasma. Blood
of them. corpuscles are of following types, each of which is
specialised for a specific function :
, Formed elements Biological function/s 6. What is meant by double circulation? What is its
significance?
A. Erythrocytes or RBCs : • Transportation of 97- Ans. Double circulation involves circulation of blood
99% of 02 as oxyHb. twice through the heart to supply it once to the body.
• Transportation of 23% It is more efficient than single circulation of fishes
of CO2 as carbami- because blood flows at higher pressure and speed
noHb. whicl1 increases the rate of not only nutrient supply
B. Leucocytes or WBCs : to the body tissues but also faster removal of wastes
- Neutrophils : Act as soldiers and eat from them.
upon the microbes by 7. Write the differences between :
phagocytosis. (a) Blood and lymph.
- Basophils : Secrete heparin and
(b) Open and closed system of circulation.
histamine so help in
anticoagulation. (c) Systole and diastole.
- Acidophils : Secrete cytotoxin on (d) P-wave and T-wave.
the microbes and help Ans. (a) Refer Table 3 of chapter 18.
in healing of wounds.
(b) Refer Table 2 of chapter 18.
- Monocytes : Act as scavengers and
remove damaged and (c) Refer Table 13 of cl1apter 18.
dead cells of the body. (d) Refer Table 19 of chapter 18.
- Lymphocytes : Secrete antibodies 8. Describe the evolutionary change in the pattern of
which provide heart among the vertebrates.
immunity against the
Ans. Refer pages 9 and Fig. 11 of d1apter 18.
pathogens.
C. Blood platelets : Secrete thromboplas- 9. Why do we call our heart myogenic?
tin and platelet factors Ans. Because in man, the nodal tissues of the heart (e.g.
at the injuries and S.A. node, A.V. node, Bw1dJe of His and Purkinje
help in blood clotting fibres) whid1 collectively form the conducting system
to prevent excessive of the heart and regulate the heartbeat, are groups
bleeding. of special cardiac muscle fibres.
10. Sino-atrial node is called the pace maker of the
2. What is the importance of plasma proteins? heart. Why?
Ans. (i) Albumins maintain the osmotic pressure of Ans. Because sino-atrial node has highest degree of
blood. rhythmicity and is first to originate the cardiac
(ii) Globulins act as antibodies and provide impulses and determines the rate of heart beat.
immunity. 11. What is the significance of atrio-ventricular node
(iii) Fibrinogen and Prothrombin help in blood and atrio-ventricular bundle in the functioning of
clotting at the injury. the heart?
(iv) Properdin kills many types of bacteria and Ans. Atrio-ventricular node acts as pace-setter and
inactivates viruses. generates the cardiac impulses which are conducted to
the ventricular muscles through the atrio-ventricular
3. Match Colunm I with column II : bundle (also called BundJe of His) and the Purkinje
Column I Colunm II fibres at the speed of 1-4 metre/second.
(a) Eosinophils (i) Coagulation 12. Define a cardiac cycle and cardiac output.
(b) RBC (ii) Universal recipient Ans. (i) Cardiac cycle involves the sequence of events
(c) AB blood group (iii) Resist infection that occur during one heart beat. It is completed
(d) Platelets (iv) Contraction of heart in 0.8 seconds.
(e) Systole (v) Gas transport (ii) Cardiac output is the volume of blood ejected
from the ventricles of heart in one minute. It is
Ans. (a) (iii); (b) (v); (c) (ii); (d) (i); (e) (iv). 5 litres per minute.
4. Why do we consider blood as a connective tissue? 13. Explain heart sounds.
Ans. Because it has large amount of intercellular matrix, Ans. Refer page 15 of chapter 18.
called blood plasma, and a three types of blood 14. Draw a standard ECG and explain the different
corpuscles. segments in it.
5. What is differences between lymph and blood? Ans. Refer page 17-18 and Fig. 19 of cl1apter 18.
Ans. Refer Table 3 of chapter 18.
