What is the main function of tight junctions in cell junctions?

Correct Answer: D

Rationale: Tight junctions prevent leakage between cells.

Correct Answer: C

Rationale: Factor VIII deficiency (hemophilia A) impairs clotting, prolonging bleeding; vascular spasm and platelet plugs normally stop bleeding quickly.

Correct Answer: C

Rationale: Calcium is essential for the clotting cascade (e.g., factor activation); vitamin K aids clotting factor synthesis.

Correct Answer: A

Rationale: Chronic blood loss depletes iron stores, common in women due to menstruation; RBCs are small/pale.

Correct Answer: D

Rationale: Low Na+ reduces osmolality; excess ADH retains water, diluting Na+.