Discuss the importance of oxygen to all living organisms, and describe how three different organisms—human, flatworm, and fern—obtain the oxygen they need.

-For humans we need oxygen to produce energy and blood cells to stay alive.

=Different living organisms like the fern plant need oxygen to perform photosynthesis.

-Flatworms get their oxygen through their skin and absorb it right through their body cells. But flatworms do not undergo cellular respiration.

Explanation:

I hope this helps :0

cell division is not regulated in tumor cells.

maybe because its impossible for balloons to lift a whole entire house.