Which Postzygotic Barrier Do Mules Illustrate

Question

Which postzygotic barrier do mules illustrate?
A) Temporal isolation
B) Hybrid inviability
C) Hybrid breakdown
D) Gametic isolation
E) Hybrid sterility

Accepted Answer

Mules, which are the offspring of a horse and a donkey, illustrate hybrid sterility. They are typically unable to reproduce due to differences in their parents' chromosome numbers, which prevents the proper formation of gametes.