I need to know two structures that allow arthropods to breathe air?

How many alleles for blood type in humans?

Which steps are part of the seafloor spreading process? Check all that apply. A crack forms in oceanic crust. Volcanoes erupt under the ocean. Molten rock rises up through the crust. Dense plates are subducted under less dense plates.

Movement of a body part toward the main axis of the body is called

Which is NOT a living part of an ecosystem? A. fungus B. sun C. tree D. fly

Why don't biologists use common names

Which factors affect a rivers load

Which sentence best captures a central idea of the biography

Is a fossil still a fossil if it is preserved artificially? For example, (Is a mummy a fossil even though it was preserved by people?)

Which type of macromolecule is the quickest source of energy for the body

Which two structures contain DNA