ANIMAL
REPRODUCTION
Reproduction
➢Process of producing again
➢The biological process by which new
organisms are produced from their
parent or parents.
Two types by which animals
reproduce:
✓ sexual
✓ asexual
SEXUAL REPRODUCTION
➢ involves both the sex cells, also called as
gametes
➢ These sex cells fuse or combine in order to
produce a new living organism that are
genetically different from their parents.
➢ The product of sexual reproduction are
offspring with two different sexes- male and
female.
Types of Fertilization
a.External Fertilization
b.Internal Fertilization
a.External Fertilization
Fertilization of egg by the sperm occurs
outside the body of an organism.
It usually occurs in aquatic
environment where the fusion of eggs
and sperms is facilitated by water.
Example:
➢ copulation
Copulation
➢Fertilization is done externally.
➢example:
✓ frogs, crabs and shrimps
b. Internal Fertilization
➢The fertilization of egg
occurs inside the body of an
organism.
Types of internal fertilization
1.Oviparity
2.Viviparity
3. ovoviviparity
1.Oviparity
➢Fertilization takes place internally
but embryo development takes
place externally.
➢Examples: turtles, birds and
chicken
2.Viviparity
➢Animals undergo internal fertilization
and the embryo develops inside the
female’s body through a placenta,
resulting in the live birth of a fully
formed offspring
➢Examples: almost all mammals
3. ovoviviparity
➢Animals lay eggs and develop the
eggs inside the mother’s body.
➢The eggs are hatched inside the
mother. Once the egg hatches, it
remains inside the mother for a
period and is nurtures from within.
➢Animals are born alive.
Examples:
➢ basking sharks, guppy fish,
scorpions and some snakes
Advantages and Disadvantages of
Sexual reproduction
❖Advantages
1.increased genetic diversity
2.New generation of species are
produced
3.Genetic traits of species are transferred
from one generation to another
❖Disadvantages
1.It takes time to find a mate and
reproduce
2. Reproduction through sexual
means is uncertain
3. Fewer offspring are typically
produced.
