In humans, three weeks after conception a structure known as the forms that will continue to develop into the central nervous system.

Which are observations about the tree on the right ,? check all that apply

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.

Development of new communities in disturbed environments, such as a burned or a clear cut forest, is called