Methods of oxygen delivery are and

Sweating and breathing is an example of differentiation specialization maintaining homeostasis metabolism

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.

As a result of climate change earths temperature is rising and sea ice is melting what is a likely effect? answer : populations of walruses and polar bears will decline