Assertion :- Calcium ions are responsible for both the activation and action of thrombin.
Reason :- An injury or trauma stimulates the platelets in blood to release coagulation-promoting substances called coagulum
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) -Assertion is true but reason is false.
Explanation:
- Assertion is accurate. Calcium ions play a crucial role in the activation of thrombin, an enzyme involved in the blood clotting cascade. Calcium ions are required for the activation of various coagulation factors, facilitating the conversion of prothrombin to thrombin, which is essential in forming blood clots.
- Reason is incorrect. An injury or trauma stimulates the platelets in blood to release coagulation promoting substances called thromboplastins which activate the mechanism of coagulation. Tissues at the site of injury also releases tissue thromboplastins. Thromboplastins help in the formation of the enzyme complex thrombokinase but not substances specifically called "coagulum."