Review paper Essay Example | Topics and Well Written Essays - 1000 words - 1

Review paper - Essay ExampleTheir shape varies from naive helical and icosahedral (polyhedral or near-spherical) forms, to more complex structures with tails or an envelope. Viruses infect cellular forms of brio and are grouped into animal, plant and bacterial viruses.There always been a discussion whether viruses are nutrition organisms. Some consider them non-living as they do not meet the criteria of the definition of life. For example, unlike most organisms, viruses do not have cells. However, viruses have genes and evolve by natural selection. The viruses mutate and compete. They have been described as organisms at the edge of life. The main feature of virus is that it usually destroys or modifies the cell it infects , thus go as a potential agent that could afflict mankind and cause numerous dieseases as ranging from unwashed cold, rabies, small pox, mumps, polio ,chicken pox , measles, rubella, hemorrhagic fevers to the Acquired Immuno Deficiency syndrome. Viral infection s in charitable as fountainhead as animal hosts usually result in an immune response and disease. Often, a virus is solely eliminated by the immune system. Antibiotics have no effect on viruses, but antiviral drugs have been essential to treat life-threatening infections. Vaccines that produce lifelong immunity can prevent virus infections. The main field of battle still now developed in antiviral therapy to stop the viral replication is targeted either on viral replication or the process of polyprotein clevage.Over a long period of known human history terrible epidemics involved humanity. The flu, smallpox, and plague killed millions of people. The epidemics of Black Death in the 14th century killed or so one third of Europes population. These terrible epidemics left traces in the genome of populations. There appeared a probability to resist diseases. Scientists find new surprising abilities of immunity to resist viral attacks. In this paper I would like to discuss some of th e