AP BIOLOGY

Detailed explanation-1: -So were they ever alive? Most biologists say no. Viruses are not made out of cells, they can’t keep themselves in a stable state, they don’t grow, and they can’t make their own energy. Even though they definitely replicate and adapt to their environment, viruses are more like androids than real living organisms.

Detailed explanation-2: -Living things use energy. Outside of a host cell, viruses do not use any energy. They only become active when they come into contact with a host cell. Once activated, they use the host cell’s energy and tools to make more viruses. Because they do not use their own energy, some scientists do not consider them alive.

Detailed explanation-3: -the flu, Ebola, measles and HIV. They are made up of DNA or RNA encapsulated in a protein shell and can only survive and replicate inside a living host, which could be any organism on earth.

Detailed explanation-4: -Viruses, particularly those that originate from animals like SARS-CoV-2, can differ greatly in their size. The smallest known animal viruses are icosahedrons, which belong to the Paroviridae and Picornaviridae families and can have a diameter ranging between 20 and 30 nm.