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 degrees and to lie in the grooves between larger, underlying cells (i.e., spiral cleavage).
-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

Spiral cleavage is characteristic of protostomes, where the fate of the cells is determined early. Separating the cells at this stage would likely result in nonviable embryos lacking many parts.

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