What substance involved in the process of blood clot formation is not made by the liver?

Correct Answer: C

Rationale: Vitamin K (C) is from diet/microbes, not liver-made; others (A, B, D) are hepatic.

Correct Answer: B

Rationale: RBCs are ~99% of formed elements, not 10% (B); other statements (A, C, D) are true.

Correct Answer: D

Rationale: Universal recipients (AB+, D) have A/B antigens, no antibodies.

Correct Answer: C

Rationale: Vasodilation widens the vessel, reducing resistance slightly (C) per Poiseuille’s law (resistance ∝ 1/radius⁴). Increase (A, B) occurs with constriction, huge decrease (D) overstates it.

Correct Answer: C

Rationale: The ductus venosus (C) shunts oxygenated blood from the umbilical vein to the inferior vena cava, bypassing the liver, into the heart.