what is a virus?

Answer 1

A virus (Latin, poison) is a submicroscopic particle that can infect the cells of a biological organism. At the most basic level viruses consist of genetic material contained within a protective protein shell, which distinguishes them from other virus-like particles such as prions and viroids. The study of viruses is known as virology, and those who study viruses are called virologists.

Viruses are similar to obligate intracellular parasites as they lack the means for self-reproduction outside a host cell, but unlike parasites, which are living organisms, viruses are not truly alive. They infect a wide variety of organisms, both eukaryotes (such as animals, insects and plants) and prokaryotes (such as bacteria). A virus infecting bacteria is known as a bacteriophage, which is used mainly in its shortened form phage.

It has been argued extensively whether viruses are living organisms. They are considered non-living by the majority of virologists as they do not meet all the criteria of the generally accepted definition of life. Among other factors, viruses do not possess a cell membrane or metabolise on their own. A definitive answer is still elusive due to the fact that some organisms considered to be living exhibit characteristics of both living and non-living particles, as viruses do.
A complete virus particle, known as a virion, is little more than a gene transporter, consisting at the most basic level of nucleic acid surrounded by a protective coat of protein called a capsid. A capsid is composed of proteins encoded by the viral genome and its shape serves as the basis for morphological distinction. Virally coded protein units called protomers will self-assemble to form the capsid, requiring no input from the virus genome - however, a few viruses code for proteins which assist the construction of their capsid. Proteins associated with nucleic acid are more technically known as nucleoproteins, and the association of viral capsid proteins with viral nucleic acid is called a nucleocapsid.

Answer 2

A virus is a biological fragment of DNA or RNA combined with some kind of molecular machinery to implant it into a host cells DNA. They are usually parasitic, and reproduce by implanting their RNA or DNA fragment into the host cell, to re-write the host cells DNA and convert that cell into a factory for making more viri.

Answer 3

Any of various simple submicroscopic parasites of plants, animals, and bacteria that often cause disease and that consist essentially of a core of RNA or DNA surrounded by a protein coat. Unable to replicate without a host cell, viruses are typically not considered living organisms.

Answer 4

what you mean from virus, we have different sort of virus in the world they have simple cell and simple DNA. and for counting of living they most live in surviving place.

Answer 5

computer virus or virus in your body?

Answer 6

A very simple life form, cannot reproduce on its own.

Answer 7

it's a pathogen, that modify's other cells...it works by injecting their DNA into other organisms....
--or
computer viruses are, malicious software that damage, your PC..hackers do them don't know why...illegal..

Answer 8

it is something that effects something else