Why is it so important for animals to keep the concentration of their body fluids constant

Answer/Explanation:

It is important to keep water concentrated because if the mixture outside the cells the cell will swell and eventually burst.

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).

organ system-an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.