(d) (i) A virus is a small infectious agent that replicates only inside the living cells of other organisms. Viruses can infect all types of life forms, from animals and plants to microorganisms, including bacteria and fungi.
(ii) According to the type of the host they infect, viruses are classified mainly into the following four types:
(a) Plant viruses including algal viruses-RNA DNA
(b) Animal viruses including human viruses- DNA/RNA
(c) Fungal viruses(Mycoviruses)-ds RNA
(d) Bacterial viruses (Bacteriophages) including cyanophages-DN
Hence answer “(d)”.
