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Classification of Organisms

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Classification of Organisms Unit 15.4 Task 1 Subgroups of virus, fungi and bacteria: Virus Fungi Bacteria Helical Mould Cocci Complex Mushroom Bacilli Polyhedral Yeast Vibrio VIRUS - Viruses are very tiny, simple organisms. They cannot grow, metabolise or reproduce. Because they are tiny, they cannot be seen even by the naked eye. It cannot multiply on its own, so it has to invade a host cell. Viruses cause many human infections, and are responsible for rare diseases. One of the rhinoviruses usually causes common colds. Viruses may contain either DNA or RNA as their genetic material. RNA viruses have an enzyme called reverse transcriptase that permits the usual sequence of DNA-to-RNA to be reversed so the virus can make a DNA version of itself. RNA viruses include HIV and the hepatitis C virus. Viruses cause many serious human diseases, for instance influenza, AIDS and rabies. The subgroups of a virus are: * Helical * Complex * Enveloped * Polyhedral Helical capsids are made up of a single type of subunit, which is loaded around a middle axis to form a helical structure that might have an empty tube or central cavity. These results in filamentous virions or rod-shapes. These can be something from highly stiff and little, to lengthy and very flexible. The genetic material is bound into the protein helix by communications among the positive charges on the protein and negatively charged nucleic acid. ...read more.


It decays on fruits and vegetables plus on bread too. Some molds are useful like species of penicillin. Whereas some are pathogenic or produce toxic chemicals, which cause serious diseases. Mould grows as long tangled stranded cells normally seen to be furry particles on food substances. When a chain of cells is present, it is called hyphae. These cells are well-organized developers of accessible nutrients during periods where growth is at its greatest, this is because a mould is capable of growing more than half a mile of new hyphae in one day. An example of mould is Mushroom. Under particular circumstances, some yeast cells secrete a thickened wall, and the cytoplasm of the single cell within separates to form four or eight cells, or spores, known as ascospores, which appear when the wall breaks. In some species, two cells fuse before going through spore formation. There are approximately 500 species in all. Yeasts, in particular those of the genus Saccharomyces, have long been of commercial significance as they are the chief agents in alcoholic fermentation. As of this, they are necessary to the making of wine, beer and other alcoholic beverages. Wild yeasts, are often active in the fermentation process. In bread, manufacture the yeasts act upon the carbohydrates in the dough, creating ethyl alcohol and carbon dioxide, which are driven off in the baking process. ...read more.


Spirochetes are lengthy, slim organisms, which look like helical coils. Several are too slim to be observed by regular light microscopy but may be noticed by dark-field microscopy or by staining with silver salts. When looked at by dark-field microscopy, spirochaetes include characteristic motility, as well as apparent rotation around their lengthy axis and a dull cockscrew rotation. Syphilis is a sexually broadcast infection caused by bacteria. It infects the genital area, mouth, lips, or anus of both women and men. Normally people obtain syphilis from sexual communication with another who has it. It may pass from mother to baby during pregnancy as well. At early stages of syphilis, it normally makes little, simple sores. At times, it causes swelling in close by lymph nodes. If not being treated, syphilis regularly causes a non-itchy skin rash, usually on the feet and hands. Symptoms may go then come back. Vibrio is shaped like a comma. Vibrio bacteria cause the tropical disease, which is characterised by brutal dehydration and diarrhoea. This disease is called cholera. Vibrio bacteria are largely halophilic and gram-negative. Nonetheless, a small umber of species is nonhalophilic, depending on their sodium chloride necessities. The majority of species are oxidase-positive. Many species are sensitive to acid pH, whereas tolerant of alkaline pH. Vibrio is usually pathogens of humans. Many species of Vibrio, counting V. parahaemolyticus, V. cholerae, and V. vulnificus, are recognised to have caused seafood-borne diseases like wound infections and septicaemia. ...read more.

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