Summary:
- Most reptiles reproduce sexually and have internal fertilization.
- Males have one or two penises that pass sperm from their cloaca to a female.
- Fertilization occurs within the cloaca, and fertilized eggs leave the female’s body.
- In a minority of species, the eggs are retained inside the female's body until they hatch.
- The shell, membranes, and other structures of an amniotic egg protect and nourish the embryo.
- They keep the embryo moist and safe while it grows and develops.