This document describes three different types of reproduction: viviparous reproduction where embryos develop inside the female body, such as in mammals; oviparous reproduction where embryos develop inside eggs outside the female body, as seen in birds and reptiles; and ovoviparous reproduction where embryos develop in eggs that are retained inside the female body, like in some fish, snakes and lizards.

1. - Viviparous
- Oviparous
- Ovoviparous

2. Viviparous development
Mammals
The embryo develops
inside the female body.
placenta
umbilical
cord
uterus
embryo

3. embryo
Fish
Birds Reptiles
Reptile or bird egg
shellchalaza
albumin
yolk
germinal disc
shell
membrane
Oviparous development
The embryo develops inside an egg, mostly
outside the female body.
hatching

4. shark
ray
snake
lizard
The embryo develops
inside an egg in the
female body.
embryo
Ovoviparous development