Answer:
It affects populations, It occurs when there is genetic variation, It selects organisms with certain traits to survive. I'm not 100% sure this is completely correct, but I just studied this in school and this sounds right. :)
If there were no decomposer then the waste would just sit there and it wouldn't be released back into the ecosystem, so then producers wouldn't have much nutrients.
B. Bacteria and Archaea, both are Prokaryote cells
