Answer:
c
Explanation:
Gas exchange. Gas exchange occurs as a result of respiration, when carbon dioxide is excreted and oxygen taken up, and photosynthesis, when oxygen is excreted and carbon dioxide is taken up. The rate of gas exchange is affected by: the area available for diffusion.
After looking at the diagram of organism, the sequence that will best represent the food chain within this particular food web is sedges-ants-frogs-kookaburras. So the correct answer choice will be number 2.
I believe the answer is A
1. proteins
2. essential
3. nonessential
hope this helps!!