Controls usually involve only one organ or tissue.
a) extrinsic
b) intrinsic
c) both a and b
d) none of the above
no one answered so i guessed b and got it right, answer is b

Animal bodies (and even plant bodies for that matter) are complex enough that life couldn't exist without enzymes. enzymes are usually large, complex biological catalysts that are expensive to make. enzymes speed up the rate of chemical reactions without being used up during the reaction (they can be reused many times). they are highly specific in the reactions they regulate. knowing what enzymes are and how they function, why does this explain why complex life forms could not exist if there were no enzymes.

The deserts of the sahara and australia are associated with

What the theory that the sun goes around earth was replaced with the theory that earth goes around the sun this was an exaple of a