(i) Meiosis is essential for all sexually reproducing organisms.
(ii) It occurs in reproductive cells, so that gametes formed are haploid or have half the number of chromosomes of those cells which are directly derived from zygote.
(iii) Two types of gametes fuse during zygote formation. As a result, zygote comes to have
double the number of chromosomes contained in gametes. Meiosis maintains a fixed number of chromosomes of a species by reducing its number by half.