Bacteria

Bacteria are prokaryotic, unicellular, microscopic organisms found essentially everywhere (ubiquitous); the field that studies them is Bacteriology. They were first observed by the Dutch scientist Anton van Leeuwenhoek in 1676, who called the tiny moving things he saw under his simple microscope 'animalcules'. This section works through their history, general character, internal structure, the Gram-staining test used to sort them into two great classes, how they feed and respire, how they reproduce, their economic importance, and the related prok …