Virus Essay essays

Virus Essay essays A virus is a strand of hereditary material coated by protein. They are too small to be seen by a light microscope and can take many shapes and forms. They can also do many different things. Viruses have neither a cell membrane nor nucleus or any other organelles. Viruses are harmful because they multiply by infecting host cells, living cells within the body, and then make copies of themselves while inside the living cell. After the new copied viruses disperse from the host cell, it dies. Some viruses, latent viruses, do not multiply, but become part of the host cell changing and becoming part of it's hereditary material. When a host cell infected with a latent virus copies itself, the viral DNA is also copied. Viruses can stay latent for many years, and certain conditions may activate the virus. Viruses attack all sorts of hosts, such as animals, plants, fungi, protists and all prokaryotes. While some many affect a broad range, other viruses can only infect certain kinds of cells. Viruses can not move by themselves, they must be transported by external means, such as wind. Most viruses only attack one kind of host cell because it must fit together exactly with the virus. A different type of virus is the bacteriophage. Bacteriophages infect bacteria by entering and releasing hereditary material. Each infected cell releases around 100 viruses. To fight viruses, we use vaccines. Vaccines are made of inactive, dead or weakened virus cells that con no longer infect host cells. Edward Jenner was the first to create a vaccine. In 1796 he developed a vaccine for small-pox by taking inactive cells from a disease called cowpox and injecting them into healthy people. Antibiotics do not work on viral infections because they are meant for bacterial infections. If not treated by vaccine, your body can try to prevent viral infections by making inferons. They are proteins created by infected cells, and are sent to other ...