Explain how early Earth's atmosphere shifted from anaerobic to aerobic.

What happens to hormone levels during ovulation

Peahens prefer to mate with peacocks that have the brightest and largest tail displays. The peacock's tail is a disadvantage to the males, because it is large and cumbersome and hinders them from escaping from predators.

Which is the first step I'm the scientific method

Michael is suffering from the flu. His mother prepares some soup for him, but he finds that the soup tastes bland. The perceived blandness happens because the receptors in his are affected by his congestion.

Which of the following statements would best describe Pseudacris crucifer? A. larger than 1.5 inches, larger than 6 inches, warts, X-shaped mark on back B. larger than 1.

The decline in response of an organism to stimulus once that stimulus becomes familiar

Some people only 'burn" when exposed to the sun. the reason they do not tan is that:

Which cells migrate through the body, increase markedly in number whenever tissue damage occurs, and may develop into cells responsible for the production of antibodies?

Which would most likely decrease the genetic variation in the human population

List three traits found in primates that distinguish them from other mammals.