When organisms convert forms of energy, what usually results?
1 All of the energy is converted into a usable form
2 Some of the energy changes into heat that escapes into the surroundings
3 All of the energy is changed into mechanical energy
4 Only chemical energy can be converted to do work

because the light is a great source of energy for the plants to survive. (i hope this )

fumikage isn't really a bird, and tsuyu does have teeth. tsuyu has a transformation quirk which still allows her to be partially human. otherwise we'd have a large frog running around. fumikage has teeth because again, he isn't a bird. his head was a quirk mixture if i'm correct.