Mar 29, 2023 · 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 …

Oct 13, 2025 · 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 …

Viruses are considered by some biologists to be a life form, because they carry genetic material, reproduce, and evolve through natural selection, although they lack some key characteristics, …

Abstract Viruses are built from short sequences of nucleic acid, either DNA or RNA wrapped in a protein shell. Until the invention of the electron microscope, it was impossible to visualize a …

Apr 12, 2025 · Viruses seem alive in some contexts but inert in others. Outside of a host, a virus is a dormant particle—it doesn’t move, doesn’t grow, and certainly doesn’t reproduce.

Oct 19, 2023 · Viruses are microscopic biological agents that invade living hosts and infect their bodies by reproducing within their cell tissue. Viruses are tiny infectious agents that rely on …

A virus is genetic material contained within an organic particle that invades living cells and uses their host's metabolic processes to produce a new generation of viral particles.