Viruses

Viruses is a creature that can't be seen but can make our body destroy in short time. Their growing is like the Einstein equation about energy. Very vast, their cell is just to slice and grown.

Science branch that study about this knowledge called as Virology. This subject is learn by many knowledge discipline background. Virus is not only live in human, but they are life in every creature in the world, human, animals and plant. From a big creature until a micro creature size. The creature which is viruses live called as host.

Viruses are extremely small parasites, that are able to reproduce only within the cells of their hosts, upon which they depend for many of their fundamental life processes. They are the causal agents of many Infection Diseases. Many hundreds of different types of viruses exist, each of which normally grows in a restricted range of hosts; different viruses, however, have a very wide variety of hosts, including bacteria, plants, and animals. Recently scientist have found that viruses are more than 1,000 times more plentiful in water than originally suspected, possibly making them the most numerous life-forms on Earth.

Any given type of viruses exists in several forms or stages. The free virus particle, or virion, consist of a molecule of nucleic acid-either DNA or RNA, depending on the specific virus-surrounded by protein and, in some viruses, also lipid and carbohydrate. The virion is inert, because it lacks many of the components that are necessary for independent life and reproduction; it does, however, provide for the transfer of the nucleic acid from host cell to host cell. Replication can occur only when the nucleic acid enters a host cell. Within the cell, the nucleic acid functions as genetic material and directs the synthetics of proteins. This production of new virions, which then are released from the cell and can initiate new cycles of infections.