Researchers and doctors hope stem cell studies can help to increase understanding of how diseases occur, and to better understand how diseases and conditions develop.
Answer: oxygen is present; electron transport chain is used
Explanation:
The atmosphere also protects living things on Earth from the sun's harmful ultraviolet radiation. A thin layer of gas called ozone high up in the atmosphere filters out these dangerous rays. The atmosphere also helps to sustain life of Earth.
I’m gonna go with D because the sun gives energy to the tree and when the animal eats the leaves or whatever off the of the tree it gives the animal energy. Hope this helps you
