NEET2003BotanyBiological ClassificationActual
Which one of the following statements about viruses is correct?
Options
- Aviruses possess their own metabolic system
- Ball viruses contain both RNA and DNA
- Cviruses are obligate parasites
- Dnucleic acid of viruses is known as capsid
Correct answer
C. viruses are obligate parasites
Step-by-step solution
Viruses consist of a protein coat known as capsid which encloses a single type of nucleic acid, either RNA or DNA. They do not have enzymes for protein synthesis. They require living host cell for multiplication, while they take over the machinery of the host cell. Thus, viruses are obligatory intercellular parasites. Related Theory Viruses can infect all cellular life forms, but each cellular species can be infected by own limited specific range of viruses. Most viruses that harm animals can not harm humans.