What role do microbes play in nutrient cycling?

Microbes are vital to control biogeochemical cycling of the elements essential for life.

Explanation:

Microbes are vital to control biogeochemical cycling of the elements essential for life. In a biogeochemical cycle,  nutrients move through the ecosystem, allowing many forms of matter being passed from one organism in one part of the biosphere, to another organism in another part of the biosphere (microorganisms can circulate through biotic or abiotic ecosystems), in this way, ensuring the supply of essential nutrients for plant crop and growth, the degradation of organic matter, the maintenance of soil quality/structure and the carbon losses to the atmosphere. In conclusion, without microbiological activity, nutrients cycling and other functions in the ecosystem would be impossible.

the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.