Question

define Bacteria ??????​

Answer 1

Answer:

Bacteria are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres 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 Earth, and are present in most of its habitats.

Explanation:

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Answer 2

Answer:

very small living things that can only be seen with special equipment (a microscope). Bacteria exist in large numbers in air, water, soil, plants and the bodies of people and animals. Some bacteria cause disease Bacteria, also called germs, are microscopic organisms not visible with the naked eye. Bacteria are everywhere, both inside and outside of your body. Bacteria can live in a variety of environments, from hot water to ice. Some bacteria are good for you, while others can make you sick.Bacteria are microscopic living organisms, usually one-celled, that can be found everywhere. They can be dangerous, such as when they cause infection, or beneficial, as in the process of fermentation (such as in wine) and that of decomposition.There are four common forms of bacteria-coccus,bacillus,spirillum and vibrio.How Many Named Species of Bacteria are There? There are about 30,000 formally named species that are in pure culture and for which the physiology has been investigated.Bacteria are microscopic, single-celled organisms that thrive in diverse environments. These organisms can live in soil, the ocean and inside the human gut. Humans' relationship with bacteria is complex. Sometimes bacteria lend us a helping hand, such as by curdling milk into yogurt or helping with our digestion.However different types of bacteria can be distinguished according to a number of characteristics:

Shape – Round (coccus), rod-like (bacillus), comma-shaped (vibrio) or spiral (spirilla / spirochete)

Cell wall composition – Gram-positive (thick peptidoglycan layer) or Gram-negative (lipopolysaccharide layer)Benefits of Bacteria

Creating products, such as ethanol and enzymes.

Making drugs, such as antibiotics and vaccines.

Making biogas, such as methane.

Cleaning up oil spills and toxic wastes.

Killing plant pests.

Transferring normal genes to human cells in gene therapy.

Fermenting foods (see Figure below).Many disease-causing bacteria produce toxins — powerful chemicals that damage cells and make you ill. Other bacteria can directly invade and damage tissues. Some infections caused by bacteria include: Strep throat.Bacteria in our gut are essential for breaking down our diet. During this breakdown, bacteria produce compounds, many of which serve as communication signals between the microbiome and the human host. Losing these bacteria can therefore reduce these important signaling molecules