Which statement best describes bacteria?
A. Bacteria are single celled prokaryotic organisms that can be helpful or harmful.
B. Bacteria were discovered in 1945 and were widely known to cause illness.
C. In the 1950s when penicillin was discovered, it was widely used to kill bacterial infections.
D. Bacteria are multicellular eukaryotic organisms, which make you sick.

The answer is A, since bacteria are single called and are all around the world, mostly helpful, but the harmful ones are called pathogens and the nice ones are called non-pathogens.

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luisvaschetto luisvaschetto · Answer 2 · 2021-08-07T03:05:49+02:00

A. Bacteria are single-celled prokaryotic organisms that can be helpful or harmful.

Bacteria are single-celled prokaryotic microorganisms that live in many different environmental conditions. Prokaryotes microorganisms do not have cell nuclei or membrane-bound organelles.

Although bacteria are generally associated with diseases, there are many species of bacteria that may be beneficial for human life.

Bacteria form part of the gut microbiota that live inside (i.e., in the digestive tract) of the human body. The gut microbiota is essential to the breakdown and absorption of nutrients.

Beneficial bacteria are also very useful for biotechnological and industrial processes. For example, Lactobacillus bacteria, also known as lactic acid bacteria, are used to produce fermented foods such as cheese and yoghurt.

Extremophiles bacteria are used in biotechnological applications. For example, the Polymerase Chain Reaction (PCR) is a widely used technique in molecular biology which is based on the use of a heat-stable DNA polymerase called 'Taq polymerase' obtained from the thermophilic bacterium Thermus aquaticus.

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