One of the factors required for the maturation of erythrocytes is 

(a) vitamin - D

(b) vitamin - A

(c) vitamin - B₁₂

(d) vitamin - C

Vitamin-K is required for 

(a) change of prothrombin to thrombin

(b) synthesis of prothrombin

(c) change of fibrinogen to fibrin

(d) formation of thromboplastin

The thick muscular projections on the walls of the ventricle are called

(a) Chordae tendineae

(b) Columnae carneae

(c) Conus arteriosus

(d) Truncus arteriosus

When type B agglutinogen is not present on the surface of RBC of a person, his plasma would contain ____ agglutinins.

1. Anti-a                          2. Anti-b

3. Both anti-a and anti-b   4. None

Oxalates and citrates are used as anticoagulants in stored blood because they:

1. Chelate calcium ions

2. Act as competitive inhibitors of vitamin K

3. Potentiate anti-thrombin III

4. Activate heparin

With respect to blood, the composition of lymph can be expressed as:

(1) No RBc, No Plateletes, Less proteins, Less calcium and phosphorus, Predominant corpuscles lymphocytes.

(2) No RBc, No Plateletes, Less proteins, More calcium and phosphorus, Predominant corpuscles lymphocytes.

(3) No RBc, Less or no Plateletes, Less proteins, Less calcium and phosphorus, Predominant corpuscles macrophages.

(4) No RBc, less Plateletes, Less proteins, Less calcium and phosphorus, Predominant corpuscles monocytes.

Histamine in blood is secreted by:

1. Mast cells

2. Macrophages

3. Eosinophils

4. Basophils

A person with AB blood group:

1. Has A and B antigens in his plasma

2. Lacks any antibodies on RBC surface

3. Can receive blood transfusion from a person of his own group.

4. Can donate blood to all other group recipients

The inter-atrial septum in the human heart can be best described as:

1. A thin muscular wall

2. A thick muscular wall

3. A thin fibrous tissue

4. A thick fibrous tissue

The sino-atrial node is the normal pacemaker of the human heart because:

1. It is located in the right atrium

2. It is the only part of the conducting system that can generate impulse

3. It can generate the maximum number of action potentials in the conducting system

4. It produces action potentials that are more in size than the other parts of the conducting system.