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).
A bc it takes in CO and releases oxygen
Answer: Dr. Balduzzi says it's important to remember that sweat is your body's main evaporative cooling system -- kind of like an internal fan. If you're exercising in cold air, your body doesn't need to produce as much sweat to keep you cool.
Explanation: