Which of the following is the primary source of a viral envelope?

• A. Host cell membrane
• B. Bacterial cell wall
• C. Viral capsid proteins
• D. Host cell nucleus

Answer: (A)

Verified step by step guidance

1. Understand that a viral envelope is a lipid bilayer that surrounds some viruses, providing an outer layer beyond the protein capsid.
2. Recall that the viral envelope is derived from the host cell during the process of viral budding, where the virus acquires part of the host's membrane.
3. Recognize that the host cell membrane is the source of the viral envelope because the virus takes a portion of this membrane as it exits the cell.
4. Eliminate other options: bacterial cell wall is unrelated because viruses infect host cells, not bacteria; viral capsid proteins form the protein shell, not the envelope; and the host cell nucleus is an organelle, not a membrane source for the envelope.
5. Conclude that the primary source of the viral envelope is the host cell membrane.