What is Fertilization?
Fusion of sperm with egg to form zygote is called fertilization,
During fertilization,the nuclei of the sperm and the nuclei of the egg fuse to form a single nucleus
This fertilised egg is called zygote
Zygote is the beginning of a new individual
Fig 3 of Lakhmir Singh
Different Types of Fertilization
It is of 2 types
- Internal Fertilization
Difference between Internal and External Fertilization
Fertilization of male and female gametes takes place inside female body
Fertilization of male and female gametes takes place outside female body
Chances of survival of offspring is more, so small number of eggs are produced
Chances of survival of offspring is less, so large number of eggs are produced
Animals like Dogs,Cat
Male sperm cells enter body from vagina
They go into uterus and from their into oviducts
Ovaries produce egg or ova
Ovaries release single egg every month to oviduct
In oviduct,one of male sperm cells fertilize with the ova to form zygote
Zygote multiples repeatedly to form embryo
Embryo develops into foetus in few months in uterus of the female
After few months,baby is formed
Female frogs and star fish lays hundreds of eggs in water.
Male deposit sperms over them.
Sperm swims in water with the help of its long tail.
When it comes in contact with eggs,fertilization takes place
NCERT Question 4 (e) - Indicate whether the following statements are True (T) or False (F):
Egg laid after fertilization is made up of a single cell. (T/F)
NCERT Question 10 (1) - Complete the cross-word puzzle using the hints given below
The process of the fusion of the gametes.
NCERT Question 3 (a) - Choose the most appropriate answer:
(a) Internal fertilization occurs
(i) in female body.
(ii) outside female body.
(iii) in male body.
(iv) outside male body.
NCERT Question 3 (c) - The number of nuclei present in a zygote is
(i) none. (ii) one. (iii) two. (iv) four.
NCERT Question 9 - Differentiate between internal fertilization and external fertilization.