because humans and reptiles and other kind of animals have what's called DNA in nuclei
D because if the species was to be removed from an ecosystem, everything that needed that species as food, or the species ould have to adapt to the foods available in the new ecosystem they live in. Hope I helped, and let me know if you are still not 100% sure about the answer, and I'll try to clarify what I said.
Answer:
B
Explanation:
The reactants of photosynthesis are CO2 and H2O and the products are C6H12O2 and O2
the answer is not exact, but it is the closest to the actual equation