A satellite was in two separate crashes . In both crashes , the satellite had the same mass . Engineers want to know about the speed and direction of the satellite after the crashes . Why would the crash affect the motion of the satellite , and which crash caused a greater change in motion for the satellite ?

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.