Question

Gametes contain one of each kind of chromosome because:
a) Crossing-over occurs during prophase
b) Two replications of DNA occur during meiosis
c) Chromatids never separate during meiosis
d) Homologous chromosomes separate during meiosis

Answer 1

Gametes are also known as sex cells. They have the ability to carry one copy of chromosomes. Male gametes are known as sperms in humans and female gametes are known as ova or eggs. The gametes are formed by the process of meiosis in which from one cell, 4 daughter cells will be formed, each carrying half the number of chromosomes as that of parents.

Complete answer:
Meiosis is a process that occurs in the cell in which the chromosome number is reduced to half and each daughter cell receives half the set of chromosomes and as a result gametes are produced.
These gametes that are haploid combine with each other to form zygote which is diploid in nature. Gametes take part in the process of fertilization.
During cell division there is a phase that is known as Anaphase 1. In this phase, the homologous chromosomes separate and each cell receives one set of chromosomes from the parent cell making the cell haploid with one type of chromosome.

Therefore, the correct answer is option (d).

Note:
A chromosome is defined as a long DNA molecule having the genetic material of an organism. They carry the information to the next cell. If the gametes carry diploid sets of chromosomes then the zygote will have 4 sets of chromosomes and hence the zygote formed would be of abnormal karyotype. There are two phases of cell cycle which are interphase and M-phase. In interphase, the cell prepares itself for the growth and division and in M-phase actual division of the cell occurs.