Question

The chromosome number of the sexually reproductive parent and their offspring is the same. Justify the statement

Answer 1

In an organism each trait is regulated by genes which are not present as a single long thread of DNA, but as separate independent pieces, each called a chromosome. Thus, each cell will have two copies of each chromosome, one each from the male and female parents. Every germ-cell will take one chromosome from each pair and these may be of either maternal or paternal origin. When two germ cells combine, they will restore the normal number of chromosomes in the progeny, ensuring the stability of the DNA of the species

The first step in sexual reproduction is gamete formation. In this step, the number of chromosomes gets halved. Thus, each gamete receives half the number of chromosomes to that of somatic cells. During fertilisation, the fusion of male and female gametes takes place, which results in the number of chromosomes in the zygote to be equal to that of somatic cells. Thus, the chromosomal number of the sexually producing parents and their offspring is the same.