How does an ectotherm regulate their body temperature? a. by using heat from the surrounding environment. b. by the processes that are involved in the flow of nitrogen through the environment. c. by producing heat within its own tissues.

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).