<prompt> Factor Xa is necessary for conversion of prothrombin to thrombin in which pathway?Only in the extrinsic pathwayOnly in the intrinsic pathwayAs part of both extrinsic and intrinsic pathwaysOnly if the normal blood clotting cascade is inhibited  <response>: c. As part of both extrinsic and intrinsic pathwaysRef: Nelsons 20e p, Ghai 8e pFactor Xa is necessary for conversion of prothrombin to thrombin in the common pathway, that means as as part of both extrinsic and intrinsic pathways. 