Question

The latest view for the origin of virus is that

• A. They arose from nucleic acid and protein found in primitive water.
• B. They arose from bacteria as a result of loss of cell wall.
• C. They arose from some of the bacteria, which had developed a nucleus only.
• D. They are modified plasmids, which are fragments of the nucleic acids of the host.

Answer 1

Answer: (D)

They are modified plasmids, which are fragments of the nucleic acids of the host.

Viruses play an important role in horizontal gene transfer and genetic diversity. The evolution history showcases the origin of viruses as to have evolved from plasmids when pieces of DNA moved between cells. As
big bits of cellular DNA became independent and some DNA stuck with cell genomes. Thus, the correct answer is option D.