1802 Words Jul 10th, 2015 8 Pages
In this essay I will be analysing micro organisms and disease. Firstly I will be defining micro organisms and then explaining the key features of the main categories of microorganisms. Followed by the roles of commensals and pathogens I will then go on to explain how micro organisms are transmitted and the routes of entry to and exit from the human body of micro organisms. I will also be explaining the logical sequence of events that occur from entry of a micro-organism to the body to the appearance of symptoms of a disease and then go onto discuss why not all infections lead to a disease. Finally I will explain a logical sequence the signs, symptoms and treatments of yellow fever which is an infectious disease.

Micro organisms are
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Fungi such as mushroom, molds, and yeasts are eukaryotic cells with a true nucleus. Most fungi are multicellular and their cell wall is composed of chitin. They obtain nutrients by absorbing organic material from their environment decomposers, through symbiotic relationships with plants (symbionts), or harmful relationships with a host (parasites). They form characteristic filamentous tubes called hyphae that help absorb material. The collection of hyphae is called mycelium. Fungi reproduce by releasing spores.

Protozoa are unicellular aerobic eukaryotes. They have a nucleus, complex organelles, and obtain nourishment by absorption or ingestion through specialized structures. They make up the largest group of organisms in the world in terms of numbers, biomass, and diversity. Their cell walls are made up of cellulose. Protozoa have been traditionally divided based on their mode of locomotion: flagellates produce their own food and use their whip-like structure to propel forward, ciliates have tiny hair that beat to produce movement, amoeboids have false feet or pseudopodia used for feeding and locomotion, and sporozoans are non-motile. They also have different means of nutrition, which groups them as autotrophs or heterotrophs.

Viruses are noncellular entities that consist of a nucleic acid core (DNA or RNA) surrounded by a protein coat. Although viruses are classified as microorganisms, they are not considered living organisms. Viruses cannot reproduce