Which of these is an example of an adaptive (or specific) immune response? A. A person's immune system responds to dirt entering the eye by increasing tear flow and flushing the dirt out of the eye. B. A person's immune system recognizes that a bacterial infection is present and signals the hypothalamus to increase body temperature. C. A person's immune system responds to

Which would be an adaptation in a rainforest, but not in a tundra? a. ability to store water for a long time b. fur that blends in with snow c. strong claws for killing prey d. a beak that can dig into thick trees

In what cells is the human genome located?

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.