In embryo, Hemopoiesis is first demonstrable in: (A) Yolk sac, (B) Liver, (C) Spleen, (D) Bone marrow
Answer is A. In the early embryo, hemopoiesis is demonstrable first in the yolk sac, followed by the liver and finally bone marrow.Reference: William&;s Obstetrics; 24th edition; Chapter 7; Embryogenesis and Fetal Morphological Development