Andrew Huberman· PhD
So the way to think about this is each pair is one strand, and you have 22 so-called autosomes, and then you have one sex chromosome. The sex chromosome will be either X or Y. So in a female, they have two X chromosomes. So in each one of the eggs that a woman has and that she's had since she was an embryo and that's contained in this vault, those eggs are, of course, going to be very immature at birth. She hasn't undergone puberty yet. And certainly, as an embryo, she hasn't undergone puberty. And those cells are going to contain 23 pairs of chromosomes. This is very important-- 23 pairs of chromosomes. The chromosomes are essentially the wrapped-up DNA that contains all the genetic information to create any cell type in the body and actually to create an entirely new individual. Now, there are 23 pairs of chromosomes, 22 of which are called autosomes. If that doesn't make sense to you, just remember, autosome, OK, there's 22 of them. And then there's one so-called sex chromosome. The sex chromosomes are either X or Y. But this is a female, so she's going to have 23 pairs of chromosomes, and she's going to have two X chromosomes for the sex chromosomes. If this is already confusing to you, don't worry, I'll make it very clear how this all relates to fertility and how it relates to chromosomal segregation and a bunch of things that I think maybe you've heard of and that perhaps were opaque to you. But I promise to make them clear. But just understand that, within each of those eggs, they have 23 pairs of chromosomes. And for those of you that like nomenclature, I'll tell you that those cells are considered diploid. They're called the diploid, and that means that they have 23 pairs of chromosomes, as distinguished from cells that are haploid where there's only one set of those 23 chromosomes. So instead of 23 pairs, there's only 23 chromosomes.