Which one of the following statements about viruses is correct?

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.