What are air masses giving brainliest and 15 points

A body of air with horizontally uniform temperature, humidity, and pressure.

Hope this helped! :D

the answer is "a.) well–developed vascular system."

explanation:

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).