Did you know that only one cell type in your body is responsible for passing on your DNA to the next generation? You may call them sperm or eggs, but biologists call them germ cells, because they represent your germline, or hereditary material that is passed on.
While males have an endless supply of sperm due to a germline stem cell, females are only endowed with a limited set of germs that eventually mature or die. Once they're all gone, hormone levels change dramatically which facilitates the onset of menopause. Because men don't naturally run out of germ cells, they are not subject to these sorts of hormonal changes.
Thank goodness I'm not a girl.
