Questions: After tissue repair is completed, factor XII catalyzes the formation of a plasma enzyme called kallikrein, that, in turn, converts an inactive plasminogen into , a fibrin-dissolving enzyme that breaks up the clot. Multiple Choice prothrombin plasminogen ences plasmin fibrin thromboplastin

The answer is the second one: plasminogen ences plasmin.

Explanation for each option:

1. Prothrombin: This is incorrect. Prothrombin is a precursor to thrombin, which is involved in the clotting process, not in dissolving clots.

2. Plasminogen ences plasmin: This is correct. Plasminogen is converted into plasmin, which is a fibrin-dissolving enzyme that breaks down clots.

3. Fibrin: This is incorrect. Fibrin is a protein that forms the mesh structure of a blood clot, not an enzyme that dissolves clots.

4. Thromboplastin: This is incorrect. Thromboplastin is involved in the clotting process by helping to convert prothrombin to thrombin, not in dissolving clots.

In summary, the correct answer is that plasminogen is converted into plasmin, which is the enzyme responsible for breaking down fibrin in blood clots.