Virus

An infectious particle composed of a protein capsule and a nucleic acid core, which is dependent on a host organism for replication. A double-stranded DNA copy of an RNA virus genome that is integrated into the host chromosome during lysogenic infection. (See Coat protein, DNA, Genome, Host, Nucleic acid, RNA, Tumor virus.)

An infectious particle composed of a protein capsule and a nucleic acid core (DNA or RNA ), which is dependent on a host organism for replication.

A noncellular biological entity that can reproduce only within a host cell. Viruses consist of nucleic acid covered by protein; some animal viruses also are surrounded by a membrane. Inside the infected cell, the virus uses the synthetic capability of the host to produce progeny viruses.

(VY-rus) In medicine, a very simple microorganism that infects cells and may cause disease. Because viruses can multiply only inside infected cells, they are not considered to be alive.

A virus is an extremely tiny infectious agent that is only able to live inside a cell. Basically, viruses are composed of just two parts. The outer part is a protective shell made of protein. This shell is often surrounded by another protective layer or envelope, made of protein or lipids (fats). The inner part is made of genetic material, either RNA or DNA. A virus does not have any other structures (called organelles) that living cells have, like a nucleus or mitochondria. These organelles are the tiny organs that maintain a cell's metabolism (life processes). A virus has no metabolism at all. Because a virus lacks organelles, it cannot reproduce by itself. To reproduce, a virus invades a cell within the body of a human or other creature, called the host. Each type of virus has particular types of host creatures and host cells that it will invade successfully. Once within the host cell, the virus uses the cell's own organelles to produce more viruses. In essence, the virus forces the cell to replicate the virus' own genetic material and protective shell. Once replicated, the new viruses leave the host cell and are ready to invade others.

A microorganism composed of a piece of genetic material - RNA or DNA - surrounded by a protein coat. To replicate, a virus must infect a cell and direct its cellular machinery to produce new viruses.

a self-replicating program that spreads by inserting copies of itself into other executable code or documents. A program into which a virus has inserted itself is said to be infected, and the infected file (or executable code that is not part of a file) is a host. Viruses are a kind of malware (malicious software). Viruses can be intentionally destructive, for example by destroying data, but many viruses are merely annoying. Some viruses have a delayed payload, sometimes referred to a bomb. The primary dow

A noncellular biological entity that can reproduce only within a host cell. Viruses consist of nucleic acid covered by protein; some animal viruses are also surrounded by membrane. Inside the infected cell, the virus uses the synthetic capability of the host to produce progeny virus. See also: cloning vector

A submicroscopic pathogen composed essentially of a core of DNA or RNA enclosed by a protein coat, able to replicate only within a living cell.

A malicious computer program designed specifically to replicate itself and spread from computer to computer. A virus may damage hardware, software, or data. [Exchange 2007]

A program designed to degrade service, cause inexplicable symptoms or damage networks.

A self-replicating program that runs and spreads by modifying other programs or files

An unwanted program which places itself into other programs, which are shared among computer systems, and replicates itself. Note: A virus is usually manifested by a destructive or disruptive effect on the executable program that it affects. 2. Self-replicating, malicious program segment that attaches itself to an application program or other executable system component and leaves no obvious signs of its presence. [INFOSEC-99]