If a piece of DNA has 600 adenines, how many thymines should it have?

20 the compound al(nh3)2 has atoms of nitrogen.

Producing disposable grocery bags consumes resources. recycling disposable bags is a solution that can recover some of the resources used to make new bags. which of the following behaviors could further refine the solution? a. disposing of bags by burning them b. reusing bags whenever possible c. using bags at once so that they do not break d. using only nonrenewable materials to make new bags subject is environmental science for apex users

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.