I was amazed when I learned this in my cultural anthropology class during my freshman year of college.
If you have a biology textbook around, flip to the section about reproduction, read it and carefully pay attention to how the textbook describes male versus female reproductive systems.
Often we find a gender bias in a section that’s supposed to be scientifically neutral. Gender bias is more prevalent in older textbooks. For example, some textbooks describe the egg as “passive” and “large” while giving adjectives such as “strong & efficiently powered” to describe sperm. In essence they play the egg as a damsel in distress while giving the sperm a knight in shining armor role.
Another way they are bias is in the fact that some textbooks will say that it’s a mystery as to why there are 7 million egg germ cells in the female embryo but most of them degenerate and die off. But they do not label the trillions of sperm in the male reproductive system that never go on to fertilize an egg as “wasteful.”
In fact textbooks go on to glorify the male reproductive system for producing millions of sperms all the while stating that the “female sheds only a single gamete each month.”
I could go on and on, read this paper published in Chicago Journals for more information.