NEET BIOLOGY

Detailed explanation-1: -All viruses contain nucleic acid, either DNA or RNA (but not both), and a protein coat, which encases the nucleic acid. Some viruses are also enclosed by an envelope of fat and protein molecules. In its infective form, outside the cell, a virus particle is called a virion.

Detailed explanation-2: -Because they can’t reproduce by themselves (without a host), viruses are not considered living. Nor do viruses have cells: they’re very small, much smaller than the cells of living things, and are basically just packages of nucleic acid and protein.

Detailed explanation-3: -Unlike cells (e.g. bacteria, plant and animal cells), viruses contain either DNA or RNA, never both; the viral nucleic acid is either single or double stranded. Viruses with a DNA core are capable of surviving in the nucleus of the cell they infect, using the host’s biochemical machinery to replicate their DNA.

Detailed explanation-4: -Viruses do not have cells. They have a protein coat that protects their genetic material (either DNA or RNA). But they do not have a cell membrane or other organelles (for example, ribosomes or mitochondria) that cells have.