Here's why:

* They have distinct male and female individuals. Male frogs produce sperm and female frogs produce eggs.

* Fertilization is external. The female frog lays eggs, and the male frog fertilizes them outside of her body.

* Offspring are genetically diverse. Because of the combination of male and female genetic material, offspring are not identical clones of the parent(s).

While some frogs can reproduce parthenogenetically (a form of asexual reproduction), this is a rare occurrence and most frogs rely on sexual reproduction.