In humans, identical twins are possible because
A) cytoplasmic determinants are distributed unevenly in unfertilized eggs.
B) extraembryonic cells interact with the zygote nucleus.
C) convergent extension occurs.
D) early blastomeres can form a complete embryo if isolated.
E) the gray crescent divides the dorsal-ventral axis into new cells.

Question

Quizplus · Accepted Answer

Identical twins in humans occur when early blastomeres (cells formed after the egg is fertilized) can individually develop into a complete embryo if they are separated. This potential for each blastomere to form a full organism underlies the possibility of identical twins, who share the same genetic material.

In Humans, Identical Twins Are Possible Because