1. Sperm and Egg: A male's testes produce sperm cells, which contain half of his genetic material (23 chromosomes). A female's ovaries produce egg cells, which also contain half of her genetic material (23 chromosomes).
2. Fertilization: During sexual intercourse, sperm travels through the vagina and into the uterus, where it can meet an egg. If a sperm cell successfully fertilizes the egg, their genetic material combines, creating a zygote.
3. The Zygote: The zygote now has a full set of 46 chromosomes, half from the father and half from the mother. This zygote contains all the genetic information necessary to develop into a baby.
4. Sex Determination: One pair of chromosomes, called the sex chromosomes, determines the sex of the baby. The mother always contributes an X chromosome. The father can contribute either an X or a Y chromosome.
* XX: If the father contributes an X chromosome, the baby will be female.
* XY: If the father contributes a Y chromosome, the baby will be male.
5. Development: The zygote undergoes rapid cell division and development, eventually becoming an embryo and then a fetus. The Y chromosome present in a male embryo triggers the development of male sex characteristics.
Important Note: This is a simplified explanation. The actual process of fertilization, development, and sex determination is incredibly complex and involves a cascade of biochemical and hormonal signals.
