Some benifits are that you can reduce stress; get more sleep; and the more sleep you get the longer you live; and the better you feel
Some costs are that if you sleep in you will probably miss stuff going on around you, and there is such thing as getting to much sleep, and when you go to bed you will have a harder time falling asleep because your body doesnt need a lot of sleep
It would be your third option. because if you look at the reproductive system both the sperm and the egg carry different amounts of genetic information.
