Which type of poem has a great hero or heroine as its main character?
a) an epic
b) a haiku
c) a ballad
d) a sonnet

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.

Where can you find prokaryotic and eukaryotic cells?

Why do we perceive objects as retaining their brightness under different lighting levels?