The blastopore is a structure that first becomes evident during
A) fertilization.
B) gastrulation.
C) the eight-cell stage of the embryo.
D) coelom formation.
E) cleavage.

Question

Quizplus · Accepted Answer

The blastopore is a structure that forms during gastrulation, which is the process in which the single-layered blastula is transformed into a three-layered gastrula. During gastrulation, cells invaginate and the blastopore is formed.

Therefore, the blastopore does not become evident during fertilization, the eight-cell stage, coelom formation or cleavage.

The Blastopore Is a Structure That First Becomes Evident During