Identical twins result from:
A) the release and fertilization of two ova
B) the release of more than 23 strands of chromosomes
C) a single ovum that splits into two parts after fertilization
D) an extra 21st chromosome produced by the father's sperm

Question

Quizplus · Accepted Answer

Identical twins result from a single fertilized ovum (zygote) that splits into two parts. As a result, both twins have the same genetic material. Option A is incorrect because fraternal twins result from the fertilization of two ova by two different sperm. Option B is incorrect because the number of chromosomes in a human being is always 46, and an extra chromosome would result in disorders such as Down syndrome. Option D is incorrect because an extra 21st chromosome (trisomy 21) also results in Down syndrome and is not related to the formation of identical twins.

Identical Twins Result From