Sex is of two types, male is characterized by XY chromosomes constitution, secondary sex characters are masculine voice, muscular body with beard and moustache in mates, with male sex organs like penis, testicles etc. The female has XX chromosome constitution, secondary sex character like Mamolry glands meant to nuse the child assured a different modulation in civilized society, feminine voice, fat at hips, sex organs ovaries, uterus, vagina etc. Sex is determined at the time of fertilization. Two types of gametes are produced by males in testicles i.e. gametes with X chromosome and gametes with Y chromosome.
Female produces one type of egg (ova) with X constitution. When egg is fertilized by X chromosome sperm, it is female XX or if it fertilized by Y chromosome sperm, it will be male XY.
Ova |
| Sperm | Zygotes after fertilization | |
X | + | X | XX | ►female |
X | + | Y | XY | ►male |
A child is a product of fusion of two cells from woman and man. Woman produces cells called ova from ovaries and man produces spermatozoa from testicles.[106]