Common step in coagulation pathway is -

Ans. is 'd' i.e., Activation of factor X o Blood coagulation pathways are divided into:-i) Intrinsic pathway (contact pathway) : It is largely an 'in vitro9 pathway and is activated when factor XII (Hageman factor or contact factor) comes in contact with negatively charged surface, e.g. glass, kaolin etc.ii) Extrinsic pathway : It is largely an in vivo pathway is activated by tissue factor (thromboplastin) at the site of tissue injury.