Q. Which among the following factors are essential for ‘blood coagulation’? Vitamin K Calcium ions (Ca++) Christmas factor Select the correct option from the codes given below:  
Answer: 1, 2 and 3
Notes: Factor IX (or Christmas factor) is one of the serine proteases of the coagulation system. Deficiency of this protein causes hemophilia B.

6

Above question is part of 10000+ MCQs for UPSC (Prelims) Paper-1 course in GKToday Android app.