Answer:
oxygen
Explanation:
Everything needs oxygen, even your cells because oxygen is crucial in process of ATP production which basically powers all of our actions. Hence, when you cells have low O2 your muscles will tire out quickly due to lack of energy thus you need to replenish them with Oxygen so that you can put an end to fatigue.
Peer review is having other professionals or people with similar skill sets review you work. It is important to help catch any errors.
Natural selection is a mechanism by which populations adapt and evolve.
Answer:
Non-functioning
Explanation:
Non-functioning of skeletal muscles occurs when the spinal cord region is damaged because spinal cord is responsible for sending information in the form of signals. The spinal cord has a network of fiber started from the brain and distributed to all the body is known as neurons. These neurons are responsible for sending instructions to the muscles from brain. If they are damaged, the body parts unable to move and can't perform their particular function.