Distinguish between a gamete and zygote. Explain their roles in sexual reproduction.

Gamete means a haploid sex cell which is sperm in males and egg (oocyte) in females. These gametes are fertilized to form a zygote.

A zygote is a diploid cell formed through the fertilization between an egg and a sperm. The zygote further divides to form an embryo.

[Extra information:

Human sperm and egg cell being germ cells are haploid in nature. They contain 23 chromosomes.

When sperm and egg cells fuse together during fertilization, it forms a zygote that is diploid in nature.

Therefore,

23 chromosomes (sperm cell, n) + 23 chromosomes (egg cell, n) = 46 chromosomes (zygote);

or 23 pair of chromosomes (zygote, 2n).

Therefore, the ratio of the number of chromosomes in the human zygote and human sperm cell = 46/23

The answer is 2:1.]