Answer:
The shelves or die and will not be able to produce sugars. Blocking electron flow prevents the formation of the proton gradient required to produce the ATP used for sugar production.
Virus: an infective agent that typically consists of a nucleic acid molecule in a protein coat, is too small to be seen by light microscopy, and is able to multiply only within the living cells of a host.
Bacteria: a member of a large group of unicellular microorganisms which have cell walls but lack organelles and an organized nucleus, including some which can cause disease.
Fungi/fungus: any of a group of spore-producing organisms feeding on organic matter, including molds, yeast, mushrooms, and toadstools.
Protozoa: a phylum or group of phyla that comprises the single-celled microscopic animals, which include amoebas, flagellates, ciliates, sporozoans, and many other forms. They are now usually treated as a number of phyla belonging to the kingdom Protista.
The Skull protects the brain.
I think the answer is evolution.