Question

Viruses are no more "alive" than isolated chromosomes because :

• A. They require both RNA and DNA
• B. They both need food molecules
• C. They both require oxygen for respiration
• D. Both require the environment of a cell to replicate

Answer 1

The correct option is D Both require the environment of a cell to replicate

Viruses are not considered "alive" because they lack many of the properties that scientists associate with living organisms. Primarily, they lack the ability to reproduce without the aid of a host cell. They 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.