The hydrosphere does not overlap with any other spheres

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.

Radiometric dating is used to tell the absolute age of materials by studying the decay rate of radioactive isotopes. the decay rates of isotopes are constant and are expressed as .

Genetic disorders can result when sister chromatids fail to seperate properly. during what phase is this problem most likely to occur?