If one says that the clearance value of glucose is zero, what does this mean?

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.

Which statement correctly describes a way that mutations increase the likelihood that a species will survive in a changing environment

Which blood cell spend most of their time in the lymphatic system?