A Sea Urchin Zygote Undergoes Its First Cell Division

Question

A sea urchin zygote undergoes its first cell division
A)5 seconds after fertilization.
B)30 minutes after fertilization.
C)90 minutes after fertilization.
D)4 hours after fertilization.
E)24 hours after fertilization.

Accepted Answer

In sea urchin, the first cell division occurs approximately 90 minutes after fertilization. This is a characteristic of sea urchin embryonic development known as "cleavage", where there is a rapid division of cells without overall growth or differentiation.