Question

what do you mean by bacteria? Discuss some beneficial bacteria and also write some harmful effects of bacteria​

Answer 1

Bacteria (singular: bacterium) are classified as prokaryotes, which are single-celled organisms with a simple internal structure that lacks a nucleus, and contains DNA that either floats freely in a twisted, thread-like mass called the nucleoid, or in separate, circular pieces called plasmids. Ribosomes are the spherical units in the bacterial cell where proteins are assembled from individual amino acids using the information encoded in ribosomal RNA.

Bacterial cells are generally surrounded by two protective coverings: an outer cell wall and an inner cell membrane. Certain bacteria, like the mycoplasmas, do not have a cell wall at all. Some bacteria may even have a third, outermost protective layer called the capsule. Whip-like extensions often cover the surfaces of bacteria — long ones called flagella or short ones called pili — that help bacteria to move around and attach to a host.

Classification

A few different criteria are used to classify bacteria. The organisms can be distinguished by the nature of their cell walls, by their shape, or by differences in their genetic makeup.

The Gram stain is a test used to identify bacteria by the composition of their cell walls, named for Hans Christian Gram, who developed the technique in 1884. The test stains Gram-positive bacteria, or bacteria that do not have an outer membrane. Gram-negative bacteria don't pick up the stain. For example, Streptococcus pneumoniae (S. pneumoniae), which causes pneumonia, is a Gram-positive bacterium, but Escherichia coli (E. coli) and Vibrio cholerae, which causes cholera, are Gram-negative bacteria.


There are three basic bacterial shapes: Round bacteria called cocci (singular: coccus), cylindrical, capsule-shaped ones known as bacilli (singular: bacillus); and spiral bacteria, aptly called spirilla (singular: spirillum). The shapes and configurations of bacteria are often reflected in their names. For example, the milk-curdling Lactobacillus acidophilus are bacilli, and pneumonia-causing S. pneumoniae are a chain of cocci. Some bacteria take other shapes, such as stalked, square or star.




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Answer 2

Answer:

DEFINITION: Bacteria are a type of biological cell. They constitute a large domain of prokaryotic organisms. Typically a few micrometers in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on the earth, and are present in most of its habitats.

BENEFITS/ADVANTAGES: Creating products such as ethanol and enzymes

                                             Making biogas such as methane

                                             Cleaning plant pests

HARMFUL EFFECTS: Causing infections or producing toxic substances

                                     Causing spoiling of food

                                     Causing infections of plants, threatening our food supply or ornamental plant

Explanation:

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