If an amphibian zygote is manipulated so that the first cleavage plane fails to divide the gray crescent, then
A) the daughter cell with the entire gray crescent will die.
B) both daughter cells will develop normally because amphibians are totipotent at this stage.
C) only the daughter cell with the gray crescent will develop normally.
D) both daughter cells will develop abnormally.
E) both daughter cells will die immediately.

Question

Quizplus · Accepted Answer

The gray crescent in an amphibian zygote is an important developmental landmark that determines the anterior-posterior axis of the embryo. If the first cleavage plane fails to divide the gray crescent, only the daughter cell with the gray crescent will contain the necessary molecular signals for proper development, and will therefore develop normally. The other daughter cell will lack these signals and will likely die or develop abnormally. Therefore, choice C is the best answer.

If an Amphibian Zygote Is Manipulated So That the First