Question

Which one of the following is necessary to start clotting of blood?

Options

• Heparin

• Serotonin

• Thromboplastin and Ca²⁺

• Fibrinogen and prothrombin

Answer 1

Thromboplastin and Ca²⁺

Explanation:

Prothromboplastin is transformed into thromboplastin in the presence of Ca++++. Prothrombin is transformed into thrombin by thromboplastin and Ca++++. Fibrinogen is then transformed into fibrin by the thrombin. This fibrin helps the blood to clot.