Identical twins develop from:

# Identical twins are produced by fertilization of:
A. 1 ovum by 1 sperm
B. 2 ova by 1 sperm
C. 1 ovum by 2 sperms
D. 2 ova by 2 sperms

The correct answer is: A. 1 ovum by 1 sperm

Twins can be either monozygotic ('identical'), meaning that they develop from one zygote, which splits and forms two embryos, or dizygotic ('non-identical' or 'fraternal'), meaning that each twin develops from a separate egg and each egg is fertilized by its own sperm cell.