Virus Definition Biology Quizlet

Virus infectious agent of small size and simple composition that can multiply only in living cells of animals plants or bacteria.

Virus definition biology quizlet. A virus is a chain of nucleic acids dna or rna which lives in a host cell uses parts of the cellular machinery to reproduce and releases the replicated nucleic acid chains to infect more cells. Learn vocabulary terms and more with flashcards games and other study tools. This is because early forms of isolating and imaging microbes couldn t capture such tiny particles. Start studying biology viruses.

The word virus comes from a latin word describing poisonous liquids. The major distinguishing characteristics of viruses are given below. They can easily seen under a normal compound microscope. Learn about the history types and features of viruses.

A virus is often housed in a protein coat or protein envelope a protective covering which allows the virus to survive between hosts. Virus sizes vary from the extremely minuscule 17 nanometre wide porcine circovirus for example to monsters that challenge the very definition of virus such as the 2 3. The size of the tobacco leaf mosaic virus is 17 mµ on the other hand parrot fever virus psittacosis chlamydia psittaci is the largest among the viruses which is a large as 450 mµ in diameter according to salle 1974 these are not virus. Viruses are ultra microscopic non cellular living particles composed solely of a nucleic acid dna or rna core surrounded by a protein envelope called capsid.

A complete virus particle that consists of an rna or dna core with a protein coat sometimes with an external envelope and that is the extracellular infective form of a virus. Viruses possess unique infective properties and thus often cause disease in host organisms.