During spermatogenesis (process of formation of sperms), each primary spermatocyte undergoes two successive divisions called maturation divisions. The first maturation division is reductional (Meiosis-I), which divides the primary spermatocyte into two haploid daughter cells called secondary spermatocytes. The latter undergo second maturation division (Meiosis-II) to form four haploid spermatids. Spermatids are transformed into spermatozoa, which are later known as sperms.