A horse has a diploid number (2n) of 64 and a donkey has 2n = 62. The hybrid of these two species, mules, have 2n = 63 and are sterile. Why are mules sterile?
A) Mules are not true hybrids.
B) One chromosome is unpaired and fails to divide properly during meiosis.
C) Horses are not able to form new species.
D) Mules cannot physically mate with each other.
E) Mules cannot physically mate with horses and donkeys.

Question

Quizplus · Accepted Answer

Mules are sterile because they have an odd number of chromosomes (63), which results in one chromosome being unpaired. This unpaired chromosome fails to divide properly during meiosis, leading to gametes that are not viable.

A Horse Has a Diploid Number (2n) of 64 and a Donkey