Question

How do germs -cells make a single set of genes from the normal two copies that all other cells in the body have ? I progeny

Answer 1

During sexual reproduction, the offspring cells or organisms acquire the genetic information of their parents. During fertilisation, the male and the female gametes fuse to form the zygote, that later develops to form the embryo. The gametes posses a haploid genome of either parent and during fusion, these characters present in the genome pass on to the offsprings to form a diploid zygote. There are 22 chromosomes pairs (autosomes) and a pair of sex chromosomes (allosomes). Thus, a single set of genes is formed from the two copies. The germ cells (having the sex chromosomes) formed initially are therefore diploid in nature. Diploid germ cells must undergo many rounds of cell division and create many new cells in order to produce haploid gametes. Meiosis, therefore, helps the germ cells make a single set of genes (haploid) from the normal two copies (diploid).