B. Hepatic portal vein. D. Renal vein.
11. The blood serum of a universal donor contains
A. Antigens A.
C. Neither antigens A or B.
B. Antigens B.
D. Both antigens A and B
12. Which one of the following events does not occur following the contraction of the
ventricle in a mammalian heart?
A. Blood flows from ventricles into arteries.
B. The blood pressure increases in the aorta.
C. Atrio-ventricular valves open.
D. Arterial valves open.
2

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]

this is more of a statement than a question. is there answers to go along with this, or is it opinion based?