what is a group of single-cell microorganisms, some of which produce poisonous substances that cause illness in humans

a. the production of carbon dioxide through the process of photosynthesis

i think its control and coordinate because im pretty sure thats what tissue does and the joints are what control movement and then your skeletal/ bones provides portection. hope that .

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).