An Interesting Bit of Biology

Females have 2 X chromosomes and males have an X and a Y, right?

Well, those X and Y chromosomes produce "gene products." All that means is that the gene codes for something, that is, it tells the cell it's in to makes something, usually a protein.

Since females have 2 X chromosomes that are identical, their cells go thru a process called lyonization. All it does it makes one of the X chromosomes in each cell inactive, otherwise it would produce twice as much of the gene products - twice as much as males.

In placental animals (most mammals), the X gene that is inactivated is random, it can either be the one the father or the mother contributed. However, in marsupials, it's always the fraternal X chromosome.

I learned that while procrastinating in writing my paper for Biology.