Question

Viruses with two types of symmetry, that is, icosahedral head and helical tail are termed as

• A. Picornaviruses
• B. Binal viruses
• C. Riboviruses
• D. None of the above

Answer 1

Answer: (B)

Binal viruses

Binal viruses are viruses having both cuboidal and helical parts i.e., they show a combination of icosahedral symmetry and helical symmetry. For example, many bacteriophages like T${}_2$.
Picornaviruses are non-enveloped, positive-stranded RNA viruses with an icosahedral capsid.
The term riboviruses encompass viruses with single and double-stranded RNA genomes.

Thus, the correct answer is option B.