Question

How do we know that the horse and the donkey are not of the same species? They do not have similar morphology. They are unable to interbreed. Offspring of a horse and donkey have a unique morphology. Offspring of a horse and donkey are unable to reproduce.

Answer 1

The answer is "Offspring of a horse and donkey are unable to reproduce."

Answer 2

Offspring of a horse and donkey are unable to reproduce.

Step-by-step explanation:

The biological concept of species states that:

A species is a group of organism with similar characteristics, that can interbreed and have a fertile offspring.

Horse + donkey = mule. A mule is a hybrid and is not fertile.