Q.Write the significance of meiosis.

Meiosis maintains a constant chromosome number across sexually reproducing generations and generates genetic variation, both of which are essential for the continuation and evolution of species.

Significance of meiosis:

1. Maintains constant chromosome number — meiosis is a reductional division that halves the chromosome number from diploid (2n) to haploid (n) during gamete formation. When two haploid gametes fuse at fertilisation, the diploid chromosome number is restored in the zygote. Without this halving step, the chromosome number would double every generation, which is prevented by meiosis.
2. Generates genetic variation — two key events during meiosis introduce new combinations of genes:
   • Crossing over — during prophase I (pachytene), homologous chromosomes exchange segments of genetic material, creating new allele combinations not present in either parent chromosome.
   • Independent assortment — during metaphase I, homologous chromosome pairs align and separate independently of one another, so different combinations of maternal and paternal chromosomes end up in different gametes. …