What might explain differences in properties between oxygen and ozone when both substances are made of the same type of atoms?

The shift of a vehicle's weight around its center of gravity is known as

Solutions to environmental problems in europe must

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.