Question

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion A : Calcium ions are essential for blood coagulation Reason R : Clotting factors required calcium ions for their activation In the light of the above statements, choose the correct answer from the options given below

• A. Both A and R are true and R is the correct explanation of A
• B. Both A and R are true but R is NOT the correct explanation of A
• C. A is true but R is false
• D. A is false but R is true

Hint:

Calcium ions: \[ Ca^{2+} \] are called clotting factor IV in blood coagulation.

Answer 1

The Correct Option is A

Concept: Blood coagulation is a complex physiological process that prevents excessive bleeding after injury. Calcium ions: \[ \boxed{ Ca^{2+} } \] play an essential role in activation of several clotting factors.

Step 1: Understand Assertion A. Assertion states: \[ \text{Calcium ions are essential for blood coagulation} \] This is correct because:
• Calcium participates in various stages of clotting cascade.
• It helps conversion of inactive clotting proteins into active forms. Without calcium:
• Normal clotting cannot occur efficiently. Thus Assertion A is true.

Step 2: Understand Reason R carefully. Reason states: \[ \text{Clotting factors require calcium ions for activation} \] This is scientifically correct. Many clotting factors:
• Need calcium ions for proper functioning. Examples include:
• Prothrombin activation
• Conversion of fibrinogen to fibrin indirectly Thus Reason R is true.

Step 3: Check whether Reason explains Assertion. Reason directly explains why calcium is necessary for blood coagulation. Because:
• Calcium activates clotting factors. Therefore Reason correctly explains Assertion.

Step 4: Select correct option. Hence: \[ \boxed{ \text{Both A and R are true and R correctly explains A} } \] Therefore correct option is: \[ \boxed{(1)} \] Final Conclusion: Calcium ions are essential in blood clotting because clotting factors require calcium for activation. Hence correct answer is: \[ \boxed{(1)} \]