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Viruses are tiny reproductive particles that reproduce only while in a living cell. Viruses have DNA and RNA, but are nonliving creatures. Viruses were first discovered in 1935, and their name comes from Latin meaning "poison." They do nothing and have no purpose while not infecting a living cell. Viruses can only infect specific cells, like for example Bacteriophage infects bacterial cell. Viruses are made up of and outer core called the Capsid, this core determines the shape of the virus, and an inner core made up of nucleic acid.
Viruses also undergo cycles in order to reproduce and harm and/or help organisms. There are two types of viral cycles known to men, the lytic cycle and the lysogenic cycle. In the lytic cycle the virus attaches itself to the host cell and nucleic acid is inserted into the cell. Next it makes copies of DNA and capsid and more viruses are assembled. Finally the viruses are released by bursting the cell and destroying it. The lysogenic cycle is slightly different than the first cycle only by a few characteristics. During the lysogenic cycle the virus also attaches and inserts nucleic acid into the cell, but instead of creating new viruses and let them be released, viral DNA is made along with the cell's DNA. That is called Provirus and the nucleic acid replicates with the cell. After that the cell can go to the lytic cycle at anytime. While in the lysogenic cycle, the virus is said to be dormant.
There are many diseases caused by viruses and one of the main ones is Morbillivirus, most commonly known as measles. The incubation period of this virus is 9-11 days and some of the symptoms are similar but not as severe as chicken pox. Morbillivirus undergoes a lytic cycle because it does not show over and over again in a person's body. Another important disease is shingles, which is caused by the virus varicella zoster and it's reactivated. The incubation time can last many years and the symptoms are...