When a single cell organism splits in too
Well it can be found in cyanobacteria and the chloroplasts of algae and plants.
Human beings contribute to the phosphorus and sulfur cycles by using chemical fertilizers for the soil. This includes mostly synthetic fertilizers that can often be full of various molecules that include phosphorus and sulfur in them.
The liver is at a #3 level of organization, an organ..which has a specific job to do in the body.
