system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:What keeps the man to woman ratio in the human population so even?
gpt
DNA is stored in large clusters inside each cell in your body known as Chromosomes. Each cell has the exact same set of DNA.

There are a total of 23 pairs, or 46 total chromosomes for humans. You get 23 of them from your mom on one side of the pair, and 23 from your dad on the other side of the pair.

One of these pairs known as the "Sex Chromosome,". If you're female, both sides of the Chromosome are known as X, so you have an XX pair of sex chromosomes.

If you're male, you have one X Chromosome, and one Y chromosome. So the pair is known as XY.

A woman will ALWAYS give an X chromosome to her child, as she only has X chromosomes to give.

A man however, can give either an X OR a Y chromosome to their child, and he makes an even number of sperm with either an X or a Y inside it.
And it is what that sperm carries, that decides the gender of the child.

And with an even number of sperm both X, and Y, means roughly an equal number of male and female children.