During the initiation of coagulation of blood, the platelets are activated by–

(1) Thrombin

(2) Trauma

(3) Ca⁺⁺

(4) Thrombokinase

To avoid Erythroblastosis Foetalis–

(1) the mother is administered anti–Rh antibodies.

(2) the baby is administered Rh antibodies.

(3) the mother is administered Rh antibodies

(4) the baby is administered anti–Rh antibodies

RBCs in human are:

(1) Biconcave-and nucleated

(2) Biconvex and nucleated

(3) Biconcave and enucleated

(4) Biconvex and enucleated

Histamine, serotonin and heparin are secreted by:

(1) Thrombocytes

(2) Lymphocytes

(3) Monocytes

(4) Basophils

B and T forms, responsible for the immune response are the type of:

(1) Thrombocytes

(2) Lymphocytes

(3) Eosinophils

(4) Granulocytes

Assertion             :       In mollusca, circulatory system is of closed type.

Reason               :       The blood of mollusca contains haemoglobin

Assertion  :       Histamine is involved in allergic and inflammatory reactions.

Reason     :       Histamine is a vasodilator

Assertion   :       Heart valves resemble swing doors in action.

Reason      :       Valves are present in the heart chamber, at the opening of the heart into large arteries and veins.

Assertion     :  Closed circulatory system is more effective than open type.

Reason        :  The closed circulatory system considerably enhances the speed, precision and efficiency of circulation.

Assertion   :       Cardiac output rises during exercise.

Reason      :       Cardiac output helps in less oxygen consumption.