What is a primary role of the viral envelope in infection?

• A. To encode viral genetic information
• B. To generate energy for replication
• C. To perform protein synthesis using host ribosomes
• D. To facilitate attachment and entry into host cells via glycoproteins

Answer: (D)

The viral envelope’s primary role in infection is to enable the virus to attach to and enter a host cell through its surface glycoproteins. The envelope, a lipid membrane borrowed from the host, harbors viral glycoproteins that specifically recognize receptors on the cell surface. Once binding occurs, these glycoproteins mediate membrane fusion or trigger endocytosis, allowing the viral genome to access the cell’s interior to begin replication. The envelope does not encode genetic information, provide energy, or drive protein synthesis itself—those tasks involve the viral genome and host cell machinery after entry.