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What is a Virus...Exactly?
The plague was thought to be a punishment from god in the middle ages. However, it was something that was more natural and fascinating then people could even imagine. First discovered in the tobacco plant by by Adolf Mayer in 1886, viruses were the cause of some of the most disastrous and grotesque events in history. As Mayer sought out to find what was killing some tobacco plants, he discovered it was not bacteria. This was puzzling. There was something else at work that was infecting the crops. Mayer filtered out all possible components and found what was called tobacco mosaic virus. Not since the discovery of bacteria has people realized how little power we have over the organisms around them, and viruses were a world researchers sought to discover.
Viruses are generally very simple. They have a protein shell that covers their genetic material. The genetic material can either be made up of DNA or its simpler constituent, RNA. A virus needs a host cell in order to reproduce, for it lack the mechanisms to carry out these functions. About one hundred times smaller than a cell, a virus latches onto a cell with “legs” made of protein strands and releases it genetic material into the host.
A virus can either inject its genetics in one of two ways. The simplest process is called Lytic cycle. The virus attaches and drills into the cell membrane. It then injects the DNA or RNA into the cell's nucleus and “tricks” the cell into reproducing the recipe to reproduce that virus. Later, the virus can break free.
The Lysogenic cycle, on the other hand, is a bit longer that the Lytic. The beginning stages are similiar—from attaching to injecting genes—but the DNA or RNA is instead mixed into the cell's DNA sequence. In this cycle, the viruses DNA can lie dormant until it “decides” to break free. HIV, for example, can lie in a host cell.
Viruses are spread in several ways. Some viruses are air born and are inhaled, some are exchanged by a carrier. One of the best ways to prevent the spread of viruses is for a person to wash his hands. Warm water is a good way to kill viruses because viruses lack the ability to regulate their own temperature and are sensitive to temperature that they have not adapted to. An example is when someone has a fever. The body is trying to overheat the invader with temperature.
Finally, vaccines can prevent an invasion of particular viruses. How this usually works is the protein of the viruses is introduced into the body. The immune system has cells called T and B cells that will recognize and remember the identity of the virus. If the virus invades the body full on, the immune system is better prepare to destroy the invader.
The body is pretty resilient when it comes to staving of pathogens. Yet some viruses adapt so quickly, medicine and the immune system fails to keep up. These genetic, protein-shelled organism have found a way to reproduce while lacking the ability to do so independently. Before the tobacco mosaic virus, researchers knew little about these tiny invaders. But now, scientists know that viruses function in two cycles and how to fight against them. So the plague was neither good nor evil; it was simply the struggle to past on genetic information in the most available way possible.