What could a human living millions of years ago have in common

What will happen if deforestation continue to destroy the green plant on the planet

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.

Each nephron is made up of capillaries that form the __ sweat glands bladder glomerulus ureter