Question

Distinguish between a gamete and zygote.Explain their roles in sexual reproduction-hatun internal and external fertilization.

Answer 1

Fertilization, also known as generative fertilisation, syngamy, and impregnation, is the fusion of gametes to produce a new individual organism or offspring and start their growth.

Complete answer:
Importance of gametes and zygotes in sexual reproduction :

Gametes are the product of meiosis and therefore carry half the number of chromosomes as the number of the parent cells. This number of chromosomes is restored during fertilisation and zygote formation. Gamete and zygote are therefore two phases of sexually reproducing organisms that help to maintain a constant number of chromosomes in each species.

Difference between Gamete and Zygote:

Gamete	Zygote
The germ cells that are mixed during sexual reproduction are called gametes, e.g. sperm (male) and ova (female).	It is the product of the fusion of male gametes and female gametes during sexual reproduction.
Gametes are unfertilized reproductive cells.	Zygote is a fertilised egg or a fertilised egg.
As a product of meiosis, gametes are always haploid cells.	Since zygote is the product of the fusion of the male and female gamete haploid, it is a diploid structure.
Haploid.	Diploid
Meiosis and cytokinesis occur	Compaction and formation of blastula occur
Found in gonads	Found in fallopian tube
No new individuals are formed.	New individuals are formed.
Has one copy of all autosomes and one sex chromosome, either X or Y.	Have two copies of all of the autosomes. Sex chromosomes may be either XX or XY.
Giving rise to the zygote	Giving rise to the foetus
Sperm: very motile. Oocyte: no-motile	Non-motile

Note: Ova and zygote are not externally active and move passively through the flow of fluid in the oviduct. The sperm cells are externally active and mobile, using their tails to swim against the flow of fluid in the oviduct.