Why might a unicellular organism need oxygen?

Most organisms also need oxygen to survive. ... In unicellular organisms, oxygen diffuses across the cell membrane into the cell. Carbon dioxide diffuses out of the cell once the concentration of carbon dioxide is higher inside the cell than it is outside of the cell.

Decomposition refers to the procedure by which organic substances are dissociated into basic organic components. The procedure is a portion of the nutrient cycle and is important for reprocessing the finite substance, which holds physical space in the biosphere.

The correct answer is option D.

When the bag was harvested it comprises of oribatid mites, springtails, pseudoscorpions, predatory mesostigmatid mites, and small spiders, this clearly demonstrates the existence of predators of the scavengers. This illustrates that the litterbag is in the later phase of decomposition.