Supplementary reading

coccus (plural cocci) a sphere-shaped bacterium.

dry without moisture.

environment the natural conditions, eg land, air and water, in which people, animals and plants live.

eukaryotic  cells containing a true nucleus, with a nuclear membrane and membrane-bound organelles.

evolution the scientific theory according to which types of animals and plants change gradually over long periods of time through a process known as natural selection to become better adapted to their environment.

family a group of related animals, plants, etc.

fermentation the extraction of energy from organic products without the involvement of oxygen or the use of microorganisms or enzymes extracted from microorganisms to carry out a wide variety of chemical reactions, which may or may not be anaerobic.