I would say the answer is A
- Anatomy of a muscle and muscles on the body ... large paired superficial muscle of the lower back. Hope this helps!
As you increase exercise and muscle activity, your heart rates increases. That is one feedback mechanism. Your heart delivers oxygen and nutrients to your muscle and other parts of the body quicker.
B. atmosphere since the atmosphere is made up of o2, co2 (a greenhouse gas) and nitrogen. those are the primary elements
D) chromosomes exchange genetic material in step 3
Explanation: the student claims that the cell division increases genetic variation, and D) is the only one which mentions exchanging genetic material/increasing variation
