Prokaryotic - The genetic material (DNA) is not enclosed in a distinct nuclear membrane.
Cell shapes can be round (coccus e.g. in streptococcal throat infection), rod-shaped (bacillus e.g. Escherichia coli which normally lives in the human gut), or spiral-shaped (spirillus e.g. in cholera)
The coccal bacteria may be arranged in rows (streptococcus e.g. in streptococcus) or in clusters (staphylococcus e.g. in staphylococcus).
Some of the rod- or spiral-shaped bacteria may move by means of a whip like flagellum (plural: flagella)
Cell wall is not made of the same chemical as plant cell walls. Monerans can be identified by whether their cell walls can be stained or not by a Gram stain. In the case of disease-causing bacteria, this is of advantage in quick identification to prescribe appropriate antibiotics.
Many can survive unfavourable conditions such as extreme dryness or heat by producing an extra spore coat.
Most reproduce asexually by binary fission approximately every 20 minutes. The bacterium duplicates its genetic material (DNA) and then splits into two smaller cells.
Some are autotrophic, i.e. produce their own nutrients from sunlight (photosynthetic), from sulphur or iron (chemosynthetic).
Some are heterotrophic, i.e. obtain their nutrients by absorbing them from other living organisms (e.g. disease-causing or pathogenic bacteria that produce toxins).
Some require oxygen to live (aerobic), and some do not (anaerobic).
Some are harmful (e.g. disease-causing or pathogenic bacteria), and some are useful (e.g. decomposing bacteria which rot dead matter to recycle nutrients into the soil).
Pasteurisation involves heating milk to more than 60 °C (when protein coagulates), and then quickly cooling it.
Did You Know That...? Every square centimetre of human skin supports 5 million bacteria.