Question

How do most unicellular organisms absorb oxygen?

Answer 1

cellular respiration takes place in each and every living cell. The mechanism of 'breathing' in unicellular organisms is different from multicellular organisms. Single celled organisms like Amoeba, Paramoecium etc. respire within there cell . Instead of the actual process of breathing, O2 simply enters in their bodies by simple diffusion. They don't have any breathing system.

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Answer 2

Hey there!
Cellular respiration takes place in each and every living cell.The mechanim "breathing" in unicellular organism is different from multi-cellular organisms.Single celled organism like Ameoba, Paramoecium, etc, respire within their different cell. Instead of actual breathing, oxygen simply enters their bodies by simple diffusion. They don't have any breathing system.

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