Question

Write any four differences between external fertilization and internal fertilization.

Answer 1

Hint:Fertilization is the fusion of male and female gametes to produce a new offspring. It can occur inside the body as in case of humans or can occur outside the body as in case of frogs.

Complete answer:
Fertilisation is the fusion of gametes inside or outside the parent body for form an embryo which will give rise to a new offspring. The fertilisation can be of two types- Internal fertilisation and external fertilisation.

Internal fertilisation	External fertilisation
It involves the fusion of the male and the female gametes inside the female body.	It involves the fusion of male and the female gamete outside the female body.
The eggs produced are less in number so the chances of survival of the offspring are more.	The eggs produced are larger in number as the chances of survival of offspring are less.
Occurs inside the body of the female.	Occurs mostly in aquatic environments.
The embryo is protected from predators by a shell or inside the body.	No protection from the predators.
Example- Human beings.	Example- frog and some aquatic animals.

Additional information External fertilisation occurs by chance. There is no copulation or intercourse between the partner (male and female). It mainly occurs in the aquatic environment as the water prevents the eggs from drying. Environmental factors and timing are the limiting factor for external fertilization.

Note: Both types of fertilisation involves the fusion of male and female gametes. It can happen inside the body of a female as in case of internal fertilisation or outside the body like in external fertilisation. Both the fertilisation produces new offspring.