C and D, but it can be B, since it occurs during cytokinesis and it begins before mitosis ends.
It is a study of ECOSYSTEM and known as ECOLOGY......
A&E Maybe hope this helps you out for this subject
D. They help plants get nutrients and water form soill This is called mutualism.
A population decrease in primary producers would affect the ecosystem negatively because everyone who ate the primary consumers would have a lack of food.
