what is a virus?
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If you mean computer virus, then this is for you: http://www.answers.com/topic/computer-virus
A virus is a tiny infectious agent that can only replicate inside the cells of living organisms. It consists of a protein coat, called a capsid, which encloses the genetic material, either DNA or RNA. Viruses can infect a wide range of organisms, including animals, plants, and even bacteria. When a virus enters a host cell, it hijacks the cellular machinery to replicate its own genetic material and produce more viruses. This can lead to various infections and diseases in the host organism.
A virus is a type of microscopic infectious agent that can replicate itself within living cells. It consists of genetic material, either DNA or RNA, surrounded by a protein coat called a capsid. Some viruses also have an outer envelope made of lipids.
To understand what a virus is, we can break it down into its components:
1. Genetic Material: Viruses contain either DNA or RNA as their genetic material. DNA and RNA are molecules that carry the genetic information of an organism. In the case of viruses, this genetic material carries the instructions necessary for the virus to replicate itself.
2. Protein Capsid: The genetic material of a virus is enclosed within a protein coat called a capsid. The capsid protects the genetic material and helps the virus to attach to and enter host cells.
3. Lipid Envelope (optional): Some viruses, known as enveloped viruses, have an additional outer envelope made of lipids. This envelope is derived from the host cell's membrane and helps the virus to enter and exit host cells.
Viruses are obligate intracellular parasites, meaning they require a host cell to replicate. They attach to specific receptors on the surface of host cells, enter the cells, and hijack the cellular machinery to produce more virus particles. This process can lead to various diseases in the host organism.
It's important to note that this is a simplified explanation of what a virus is. If you would like a more detailed explanation or have any specific questions, feel free to ask!