Viruses: Definition, Types, Characteristics & Facts - Cleveland Clinic
2023年3月29日 · Virus. Viruses are microscopic organisms that can infect hosts, like humans, plants or animals. They’re a small piece of genetic information (DNA or RNA) inside of a protective shell (capsid). Some viruses also have an envelope. Viruses can’t reproduce without a …
Virus | Definition, Structure, & Facts | Britannica
2024年10月24日 · Virus, infectious agent of small size and simple composition that can multiply only in living cells of animals, plants, or bacteria. Viruses possess unique infective properties and thus often cause disease in host organisms. Learn about the history, types, and features of …
Virus - Wikipedia
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. [1] Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. [2] [3] Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity.
Virus - Definition, Structure, Classification, Examples | Biology ...
2018年8月25日 · 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.
Virus Definition & Meaning - Merriam-Webster
The meaning of VIRUS is any of a large group of submicroscopic infectious agents that are usually regarded as nonliving extremely complex molecules, that typically contain a protein coat surrounding an RNA or DNA core of genetic material but no semipermeable membrane, that are capable of growth and multiplication only in living cells, and that ...
Virus - National Human Genome Research Institute
4 天之前 · A virus is an infectious microbe consisting of a segment of nucleic acid (either DNA or RNA) surrounded by a protein coat. A virus cannot replicate alone; instead, it must infect cells and use components of the host cell to make copies of itself.
Overview of Viruses - Overview of Viruses - The Merck Manuals
Viruses are among the smallest microbes, typically ranging from 0.02 to 0.3 micrometer, although several very large viruses up to 1 micrometer in length (megavirus, pandoravirus) have recently been discovered. Viruses depend completely on cells (bacterial, plant, or animal) to reproduce.
virus | Learn Science at Scitable - Nature
A virus is an infectious agent that can only replicate within a host organism. Viruses can infect a variety of living organisms, including bacteria, plants, and animals....
Viruses - Education | National Geographic Society
2023年10月19日 · Viruses are tiny infectious agents that rely on living cells to multiply. They may use an animal, plant, or bacteria host to survive and reproduce. As such, there is some debate as to whether or not viruses should be considered living organisms.
Viruses: Definition, Structure, Classification | SpringerLink
Viruses are infectious units with diameters of about 16 nm (circoviruses) to over 300 nm (poxviruses; Table 2.1). Their small size makes them ultrafilterable, i.e. they are not retained by bacteria-proof filters.