What is the difference between topsoil and clay?

The ocean layer of a rapid temperature change with deph is known as the

Prompt compare the three types of volcanic mountains in terms of shape, type of eruption, and the minerals that make up the volcano

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.