Answer: Where it gets food.
Explanation: There is multiple tropic levels btw
Oxygen has to be the answer because if plants and animals use it they both need these things
They are carried out by proteins
"Homeostasis" is the regulation of internal environment. It can be perceived as "same standstill" when translating the prefix and suffix. The word really does fit as it's describing the action of changing things inside your body to keep up with the environment, examples including sweating to cool off and shivering to warm up.
