HELP ASAP PLS

What is the term for the two sets of chromatids formed in the parent cell a.haploid b.diploid c.gamete d.tetrad

Matthew decided he wanted to hike up mount everest. on his way to the top, it began to snow and the temperature dropped to -10°f. matthew forgot to wear a heavy jacket so his body began to shiver beyond control. in this case, matthew's body shivering is the to a drop in temperature. * 0 points reflex stimuli responce environmental facto

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.