In a review in the NYRoB, Richard Lewontin says
“The other exception to random inheritance is not in the chromosomes, but in cellular particles called ribosomes that contain not DNA but a related molecule, RNA, which has heritable variation and is of basic importance to cell metabolism and the synthesis of proteins. Although the cells of both sexes have ribosomes, they are inherited exclusively through their incorporation in the mother’s egg cell rather than through the father’s sperm. Our ribosomes, then, provide us, both male and female, with a record of our maternal ancestry, uncontaminated by their male partners. “
I didn’t know that.
He also says: “ The Y chromosome carries very few genes. We know this to be true because, very rarely, an individual is born having received, as usual, one X chromosome from the female parent but, abnormally, neither an additional X chromosome nor a Y chromosome from the male parent. This individual, called an “XO” type, is a sterile female but otherwise is normal. “
I grew up with a class mate who had Turner syndrome, XO. That’s not the impression I got, but people at Harvard evidently know a lot of things that I don’t.