A student encounters an animal embryo at the eight-cell stage. The four smaller cells that comprise one hemisphere of the embryo seem to be rotated 45° and to lie in the grooves between larger, underlying cells. If we were to separate these eight cells and attempt to culture them individually, then what is most likely to happen?
A) All eight cells will die immediately.
B) Each cell may continue development, but only into a nonviable embryo that lacks many parts.
C) Each cell may develop into a full-sized, normal embryo.
D) Each cell may develop into a smaller-than-average, but otherwise normal, embryo.

Question

Quizplus · Accepted Answer

The description of the embryo suggests spiral cleavage, typical of protostomes. In such organisms, the fate of the cells is determined early, and separated cells are unlikely to develop into complete embryos.

A Student Encounters an Animal Embryo at the Eight-Cell Stage