Answer:
It could be embreology. (I think i spelled that wrong)
Explanation:
It is a way to compare the embreos of two species to see the similarities between the two. If there are similarities then they have a common ancestor. If they don't have similarities then they arent from the same family.
I'd say heat, more specifically sunlight.
Why?
Because sun is the form of energy needed for plants to grow and live. Plants in turn are the form of energy needed for herbivores to live that later on turn out to be the form of energy needed by the carnivores. When these die, decomposers will be the ones to take advantage of the energy.
As you can see an ecosystem has already been formed: producers, secondary consumers, tertiary consumers or decomposers.
Hope it helped,
Happy homework/ study/ exam!
A specific organ on which a hormone, drug, or other substance acts
DNA..........is the correct answer
The correct answer is c because glaciers are one of our main sources for fresh water
