In both birds and mammals, gastrulation occurs in the
A) hypoblast.
B) epiblast.
C) blastodisc.
D) trophoblast.
E) blastocyst.

Question

Quizplus · Accepted Answer

Gastrulation is the process of forming the three germ layers (endoderm, mesoderm, and ectoderm) during embryonic development. In birds and mammals, gastrulation occurs in the epiblast layer, which is the upper layer of cells in the blastodisc (in birds) or blastocyst (in mammals). The hypoblast or yolk sac (in birds) and the trophoblast (in mammals) do not undergo gastrulation since they do not contribute to the formation of the embryo proper.

In Both Birds and Mammals, Gastrulation Occurs in the