All the biological macromolecules contain carbon, hydrogen and oxygen. however, most do not contain nitrogen. the category that contains nitrogen are what

Compare the shapes of the bones of the human skull with the shapes of the bones of the human leg. how do the shapes differ? why are the shapes important?

Body temperature is tightly regulated in mammals for example when external temperatures drop too much the body of a mammal response by in order to it's core temperature.

Which of the following statements is a scientific claim? a. the early solar system had large amounts of water; so, the oldest objects in the solar system should also be abundant in water. b. earth is shaped like a sphere even if not all of the scientific observations related to its shape support this idea. c. the mass of the universe is much greater than current models predict; it is not possible to explain this inconsistency. d. planet earth is abundant in water, but there is no way to scientifically determine from where earth's water originated.