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

Question

nathalyn · Answer

Oxygen is the most essential element for survival of all living things.Oxygen supports life on earth and without oxygen ther would probably be no life on earth.Oxygen is used for all metabolic functions in livind organisms.
 human-get their oxygen supply directly from plants and few blue green algae.Oxygen then is taken by the lungs and is supplied through out the body.
 flatworm-they get oxygen from their skin or from their host organism 
fern-they are green plants so they prepare oxygen through photosynthesis

anonymous · Answer

Actually there are quite of few species that oxygen would kill.  Lots of obligate anaerobes, but I guess oxygen is still important, important that it is not there.

anonymous · Answer

Oh, and most oxygen is not from plants but from algae.