Why do cells divide even after an organism reaches adulthood?

Astudent visits the beach during a very hot day she steps on the santa and jumps because it is so hot what type of heat transfer is demonstrated by the sand in this example

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.

Why did rutherford say that bombarding atoms with particles was like "playing with marbles" what