Solveeit Logo
Login

Question

Question: Which of the following statements are correct? i) Ca$^{+2}$ is necessary for blood coagulation ii)...

Which of the following statements are correct?

i) Ca+2^{+2} is necessary for blood coagulation

ii) Coagulation in blood vessel is prevented during normal condition by heparin

iii) Clotting of blood involves changes of fibrinogen to fibrin by thrombokinase

iv) Blood clotting involves cascade process involving a number of factors present in the plasma in an inactive form

A

i, ii and iv

B

i and iii

C

i, ii and iii

D

iii and iv

Answer

i, ii and iv

Explanation

Solution

  1. Statement i) Ca+2^{+2} is necessary for blood coagulation: Calcium ions (Ca+2^{+2}) are essential cofactors for several steps in the blood clotting cascade, including the activation of various clotting factors. Without Ca+2^{+2}, blood coagulation cannot proceed normally. Thus, this statement is correct.

  2. Statement ii) Coagulation in blood vessel is prevented during normal condition by heparin: Heparin is a natural anticoagulant found in the body, primarily produced by mast cells. It prevents intravascular clotting by enhancing the activity of antithrombin III, which inactivates key clotting factors like thrombin and Factor Xa. Thus, this statement is correct.

  3. Statement iii) Clotting of blood involves changes of fibrinogen to fibrin by thrombokinase: The conversion of soluble fibrinogen to insoluble fibrin, which forms the clot mesh, is catalyzed by the enzyme thrombin. Thrombokinase (also known as Factor Xa or prothrombinase complex) is responsible for converting prothrombin into thrombin, not directly fibrinogen to fibrin. Thus, this statement is incorrect.

  4. Statement iv) Blood clotting involves cascade process involving a number of factors present in the plasma in an inactive form: Blood coagulation is a complex cascade of enzymatic reactions involving numerous clotting factors (proteins) that circulate in the blood plasma in an inactive (zymogen) form. Upon injury, these factors are sequentially activated, leading to a rapid and amplified response culminating in clot formation. Thus, this statement is correct.

Based on the analysis, statements i, ii, and iv are correct.

Answer: The correct statements are i, ii, and iv. Therefore, the correct option is i, ii and iv.