Question

Give biological reasons for the following:
Gametes have a haploid number of chromosomes.

Answer 1

Gametes are also referred to as sex cells, gametes are reproductive cells of an entity. These carry one copy of the chromosome. Male gametes are referred to as sperms while female gametes are known as ova or eggs. The reproductive cells are a result of the process of meiosis.

Complete answer: Meiosis during which the chromosome number is reduced to half and each daughter cell receives half the set of chromosomes, as result gametes are produced.
These gametes, the egg, and the sperm unite to form a zygote. This is a diploid zygote. The zygote would have twice the number of normal chromosomes and the organism produced would be abnormal, if both of the gametes were diploid.
In humans the mode of reproduction is sexual, it involves the fusion of haploid gamete cells from each parent with half the normal number of chromosomes to make a new cell containing both parents' genetic material. The cells obtained from each parent that combine to form the zygote are called gametes.
The gametes take part in the process of fertilization and after fertilization from the zygote.
The gametes are a result of meiosis hence they have a haploid number of chromosomes.
Hence the gametes have a haploid number of chromosomes to maintain a constant number of chromosomes in a species.

Additional Information: Meiosis, a two-step process gives rise to gametes. The outcome is 4 haploid daughter cells, each of which contains only one set of chromosomes. Through the process of fertilization, they unite forming the zygote.

Note: Gametes are the reproductive cells of an entity. A chromosome is defined as a long DNA molecule with part or all of the genetic material of an organism. Egg and sperm are haploid. They have a haploid number of chromosomes, the gametes are produced as a result of meiosis.