When Would Monozygotic (Identical) Twins Be Produced

Question

When would monozygotic (identical) twins be produced?
A) One sperm fertilizes two different eggs.
B) One egg is fertilized by two different sperm.
C) One embryo splits into two embryos.
D) Two different sperm fertilize two different eggs.

Accepted Answer

Monozygotic (identical) twins are produced when one embryo splits into two embryos during early development. This results in each twin having the same genetic makeup and being the same sex. Option A and D describe fraternal (dizygotic) twins, where two separate eggs are fertilized by separate sperm. Option B does not occur naturally in humans as each egg can only be fertilized by one sperm.