Enveloped versus nonenveloped viruses: Which one of the following viruses is enveloped?

Introduction / Context:Envelope status influences environmental stability, disinfection, and entry mechanisms. Enveloped viruses bud through host membranes and carry lipid bilayers; nonenveloped viruses rely on robust capsids.

Given Data / Assumptions:

• Adenoviruses: nonenveloped, icosahedral DNA viruses.
• Herpesviruses: enveloped, large DNA viruses with tegument.
• Polioviruses: nonenveloped, positive-sense RNA (Picornaviridae).

Concept / Approach:Among the listed choices, only herpesviruses possess a lipid envelope surrounding their capsid. This envelope bears glycoproteins essential for attachment and fusion but also makes the virion more susceptible to detergents and desiccation.

Step-by-Step Solution:Match each virus family to envelope status.Identify herpesviruses as enveloped; others listed are nonenveloped.Choose “Herpes.”

Verification / Alternative check:Electron micrographs reveal a membrane bilayer and spikes surrounding herpesvirus nucleocapsids, unlike adeno or polio.

Why Other Options Are Wrong:Adeno and polio lack envelopes; “None of these” is incorrect because herpes is enveloped.

Common Pitfalls:Equating “has spikes” with “is enveloped”—nonenveloped viruses can have protruding capsid proteins but no lipid bilayer.

Final Answer:Herpes