Answer:
cellular respiration...that's breathing out of humans
and through human activities like burning of fossil fuels...
Environments are always changing so organisms need to adapt to survive. The organisms that survive are the ones that are fit to live in that environment, which is where survival of the fittest comes into play.
They move blood through out your body
Answer:
The testes
Explanation:
the testes are two oval shaped male reproductive glands that produce sperm and hormone testoterone
