What is a Sex Chromosome?
How is a baby made, and what can make them boys or girls? (See the lesson on sexual reproduction here)
During sexual activity (mating), the male releases the sperm cell and the female releases the ova (female cell). Remember we said previously that the human body has 23 pairs of chromosomes? Yes, the 23rd chromosome is your sex chromosomes. Boys carry XY chromosomes and girls carry XX cromosomes. During fertilization, each parent contributes a cell each. The female always contributes and X cell (because that all she has, XX chromosome) The male contributes either an X or a Y cell. The male has no control over this, as it is purely random.
If the male releases and X chromosome, it adds to the X chromosome of the female, it forms an XX— and the gender of the baby will be a girl. If the male releases a Y chromosome and adds to the females X chromosome, it forms an XY and the gender of the baby is a boy.
In recent years, it is possible to have IVF which means In vitro fertilization. This is where the female and male cells are taken from the parents and fertilized in a lab. In IVF, it is possible to choose which sex chromosomes to fertilize. This means you can choose to have a boy or girl.
This technology is highly debated, because many people think that it is against nature or God to choose these things and should be left for nature to decide. What do you think too? You can debate this with your family and friends.