An embryo with meroblastic cleavage, extraembryonic membranes, and a primitive streak must be that of
A) an insect.
B) a fish.
C) an amphibian.
D) a bird.
E) a sea urchin.

Question

Quizplus · Accepted Answer

Embryos with meroblastic cleavage have incomplete cell division and is only found in yolk-rich eggs. Extraembryonic membranes are found in amniotes and are used for gas exchange, waste storage, and protection. The primitive streak is the beginnings of the mesoderm and is only found in chordates. Therefore, the embryo described can only be that of a bird.

An Embryo with Meroblastic Cleavage, Extraembryonic Membranes, and a Primitive