Question 1

The WBC count of a person's blood sample is 8000/cu.mm. How many eosinophils and lymphocytes would be in the same blood sample approximately ?

Accepted Answer

Total WBC count = 8000/cu.mm. Eosinophils constitute 2 - 3\% of total WBCs. Number of eosinophils = 2 100 8000 to 3 100 8000 = 160 - 240/cu.mm. Lymphocytes constitute 20 - 25\% of total WBCs. Number of lymphocytes = 20 100 8000 to 25 100 8000 = 1600 - 2000/cu.mm. Answer: 160 - 240/cu.mm and 1600 - 2000/cu.mm, respectively

Question 2

Which of the following statements is incorrect ?

Accepted Answer

Blood coagulates or clots in response to an injury or trauma to prevent excessive loss of blood from the body. A blood clot or coagulum is formed mainly of a network of threads called fibrins in which dead and damaged formed elements of blood are trapped. Fibrins are formed by the conversion of inactive fibrinogens present in the plasma by the enzyme thrombin. Therefore, the statement that fibrinogen is produced from fibrin is incorrect. Answer: Fibrinogen is produced from fibrin

Question 3

The opening between the right atrium and the right ventricle is guarded by __________.

Accepted Answer

The opening between the right atrium and the right ventricle is guarded by a valve formed of three muscular flaps or cusps, known as the tricuspid valve. The bicuspid or mitral valve guards the opening between the left atrium and the left ventricle. The semilunar valves guard the openings of the right and left ventricles into the pulmonary artery and the aorta, respectively. The sino-atrial node is a specialized cardiac musculature present in the right upper corner of the right atrium.

Question 4

The number of action potentials generated by sino-arterial node (SAN) in a healthy human is __________ per minute.

Accepted Answer

The sino-atrial node (SAN) is a specialised patch of cardiac musculature present in the right upper corner of the right atrium. It has the ability to generate action potentials without any external stimuli, making it autoexcitable. The SAN can generate the maximum number of action potentials, which is 70-75 per minute in a healthy human. This rate of action potential generation is responsible for initiating and maintaining the rhythmic contractile activity of the heart, which is why the SAN is c

Question 5

Select the incorrect statements with reference to Rh grouping : A. Erythroblastosis foetalis is a condition observed having foetus with Rh^ -ve blood and mother with Rh^ +ve blood. B. Rh antigen is ob

Accepted Answer

Statement A is incorrect because erythroblastosis foetalis occurs when a pregnant mother is Rh^ -ve and the foetus is Rh^ +ve . Statement B is correct as nearly 80\% of humans have the Rh antigen on the surface of their RBCs. Statement C is correct because Rh compatibility must be checked before blood transfusion to prevent immune reactions. Statement D is correct as Rh incompatibility arises when an Rh^ -ve mother carries an Rh^ +ve foetus. Statement E is incorrect because erythroblastosis foet

Question 6

Cardiac activities of the heart are regulated by: A. Nodal tissue B. A special neural centre in the medulla oblongata C. Adrenal medullary hormones D. Adrenal cortical hormones Choose the correct answ

Accepted Answer

Normal cardiac activities of the heart are regulated intrinsically, i.e., auto regulated by specialised muscles (nodal tissue), hence the heart is called myogenic. A special neural centre in the medulla oblongata can moderate the cardiac function through autonomic nervous system. Sympathetic nervous system can increase the rate of heartbeat, ventricular contraction and thereby cardiac output. Parasympathetic neural signals decrease the rate of heartbeat, speed of conduction of action potential a

Question 7

'Lub' sound of Heart is caused by the ______

Accepted Answer

The correct answer is option (4) because LUB is the first heart sound and it is produced by closing of AV valves; (tricuspid valve in between right atrium and right ventricle) and (bicuspid /mitral valve in between left atrium and left ventricle), during ventricular systole. - Option (1) is incorrect as closure of the semilunar valves produce the second heart sound called 'DUB'. - Option (2) is incorrect because opening of valves are not responsible for production of heart sounds 'LUB' and 'DUB'

Question 8

Following are the stages of pathway for conduction of an action potential through the heart A. AV bundle B. Purkinje fibres C. AV node D. Bundle branches E. SA node Choose the correct sequence of path

Accepted Answer

Correct answer is option (4) because the correct pathway of conduction of action potential is SA AV node AV bundle Bundle branches Purkinje fibres

Question 9

The mother has A + blood group the father has B + and the child is A +. What can be the possibility of genotypes of all three, respectively? A. I^A I^A |I^B i | I^B i B. I^A I^A |I^B i | I^A i C. I^B

Accepted Answer

The child blood group is ( A ^* ) that means he must have received ( i ) allele from the father i.e. the father genotype is (I^B I ). While mother can have ^ ^ or ^A genotype. So, the possible genotypes of all three i.e. mother, father and child respectively would be either (B) I^A I^A |I^B i | I^A i (E) I^A i |I^B i | I^ A_i

Question 10

As per ABO blood grouping system, the blood group of father is B ^ + , mother is A ^ + and child is O ^ + . Their respective genotype can be A. ^ B / / \|^ A^A / / i i B. . I^ B |^ B / . . |^ A |^ A /

Accepted Answer

Genotype of father with blood group B ^ + =І^ B / / i ^ B Genotype of mother with blood group A ^ + = A _ A / . |^ A Genotype of child with blood group O ^ + = ii Hence only ' A ' is correct.

Question 11

A person with blood group ARh ^ - can receive the blood transfusion from which of the following types? A. BRh ^ - B. ABRh ^ - C. ORh ^ - D. ARh ^ - E. ARh ^ * Choose the correct answer from the option

Accepted Answer

The correct answer is option (4) because recipient is A blood group with Rh (- ve ) antigen, hence cannot receive blood from any blood group with Rh (+ ve ) antigen and as A blood group individuals have anti-B antibodies in plasma. So, donor could be O ( Rh - ve ) and A ( Rh - ve ) only. Options (1), (2) and (3) are not correct answers because B ^ - , AB ^ - and A ^ + blood groups will lead to serve clumping reaction.

Question 12

Match List I with List II : array |l|l|l|l| & List I & & List II \ A. & P wave & I. & Heart muscles are electrically silent. \ B. & QRS complex & II. & Depolarisation of ventricles. \ C. & T wave &

Accepted Answer

The correct answer is option no. (1) as A. P wave - III. Depolarisation of atria. B. QRS complex - II. Depolarisation of ventricles. C. T wave - IV. Repolarisation of ventricles. D. T-P gap - I. Heart muscles are electrically silent.

Question 13

Given below are two statements : Statement I : Bone marrow is the main lymphoid organ where all blood cells including lymphocytes are produced. Statement II : Both bone marrow and thymus provide micro

Accepted Answer

The correct answer is option no. (4) as both statements I and II are correct. In humans, the bone marrow is the main lymphoid organ where all blood cells including lymphocytes are produced. Both bone-marrow and thymus provide micro-environments for the development and maturation of Tlymphocytes. Options (1), (2) and (3) are incorrect.

Body Fluids and Circulation — Previous Year Questions & Solutions