Which of the following is always present in a virus?
Ans. is 'c' i.e., RNA or DNA Viruses are obligate intracellular parasites.They lack enzymes necessary for protein and nucleic acid synthesis and are dependent for replication on the synthetic machinery of host cells - so, they cannot grow in cell free culture media.They do not have cellular organization - do not contain ribosome, ER, mitochondria etc.They contain only one type of nucleic acid, either RNA or DNA, never both.Virion may be enveloped or nonenveloped (naked).
Enzymes
Envelop
RNA or DNA
All of the above