4. • Ways on How Animals Reproduce
1. Oviparous- Egg laying
-animals that lay eggs to produce youngs.
1. Viviparous- live bearers
-animals that give birth to live mature
youngs.
5. Mode of Reproduction of Different
Animals
Group Oviparous Viviparous
Mammals Only few primitive
mammals that exist. They
are found in Australia and
New Guinea
Nearly all mammals
Birds All Birds None
Reptiles Most ( ex. Turtles,crocodile
etc.)
Some lizards and snakes
Amphibians Almost all (frogs, toad, etc.) A few species of frogs
Fish Most species A few species ( e.g. shark,
guppies, etc.)
6. • Reproduction in animals involves fertilization of egg
cell by a sperm cell.
Types of fertilization:
1. Internal Fertilization- happens inside the mother’s
fallopian tube. And the zygote acquire nourishment
from the mother through the placenta.
-happens in most of the viviparous organisms.
2.External Fertilization- happens outside like in the case
of frogs. The females lay their eggs and the males fertilize
them by releasing sperms.
7. Parthenogenesis
• Is a type of reproduction which does not
need the fertilization of the egg cell.
• The egg cell develops into a new
individual even without the fertilization
of the sperm.
• It often happens in arthropods,
amphibians, fish, birds, and reptiles but
not in mammals.
