EVERYDAY SCIENCE

Detailed explanation-1: -Viruses are small obligate intracellular parasites, which by definition contain either a RNA or DNA genome surrounded by a protective, virus-coded protein coat. Viruses may be viewed as mobile genetic elements, most probably of cellular origin and characterized by a long co-evolution of virus and host.

Detailed explanation-2: -All viruses are obligate parasites; that is, they lack metabolic machinery of their own to generate energy or to synthesize proteins, so they depend on host cells to carry out these vital functions.

Detailed explanation-3: -Bacteria and viruses can live outside of the human body (such as on a countertop) sometimes for many hours or days. But parasites need a living host to survive.

Detailed explanation-4: -All viruses are obligate pathogens as they are dependent on the cellular machinery of their host for their reproduction. Obligate pathogens are found among bacteria, including the agents of tuberculosis and syphilis, as well as protozoans (such as those causing malaria) and macroparasites.

Detailed explanation-5: -A Parasitic Virus (also referred to as a file virus) is a type of virus that spreads by attaching itself to another program. When a program that is infected with a parasitic virus runs, the virus code runs as well, and the computer’s operating system gives the virus code the same rights as the program.