What is the missing word? substances can move into or out of cells by diffusion.

If scientists are wrong about earth's age based on radioactive material and the decay rates are really much faster, how would nuclear power plants be affected?

How are the testes and ovaries similar? a. both produce sex cells. b. both connect internal reproductive organs to the exterior. c. both transport sex cells from their site of production. d. both store mature sex cells.

Hemoglobin is a proton that carries oxygen around your body what is hemoglobin made from