Which virus is the smallest DNA virus?

Which virus is the smallest DNA virus?

• A. Adenovirus
• B. Parvovirus B19
• C. Herpes simplex virus
• D. Varicella-zoster virus

Answer: (B)

The smallest DNA virus is defined by its tiny genome and virion size. Parvoviruses have the smallest DNA genomes, about 5 kilobases, and a tiny, nonenveloped icosahedral particle (roughly 18–26 nm). Parvovirus B19 is a classic example of this group. The other viruses listed carry much larger genomes: adenovirus has a double-stranded DNA genome of about 26–34 kilobases; herpes simplex and varicella-zoster viruses have even larger genomes, well over 100 kilobases. So Parvovirus B19 is the best answer because it is the smallest DNA virus among them. The small genome also means fewer genes and a greater dependence on the host cell’s machinery for replication.

The smallest DNA virus is defined by its tiny genome and virion size. Parvoviruses have the smallest DNA genomes, about 5 kilobases, and a tiny, nonenveloped icosahedral particle (roughly 18–26 nm). Parvovirus B19 is a classic example of this group. The other viruses listed carry much larger genomes: adenovirus has a double-stranded DNA genome of about 26–34 kilobases; herpes simplex and varicella-zoster viruses have even larger genomes, well over 100 kilobases. So Parvovirus B19 is the best answer because it is the smallest DNA virus among them. The small genome also means fewer genes and a greater dependence on the host cell’s machinery for replication.