The projections on the surface of animal viruses primarily allow the virus to —

• A. attach to specific host cell receptors
• B. degrade host cell membranes
• C. synthesize viral DNA
• D. produce energy for viral replication

Answer: (A)

Verified step by step guidance

1. Understand that the projections on the surface of animal viruses are typically glycoprotein structures known as spikes.
2. Recognize that these spikes play a crucial role in the virus's ability to recognize and bind to specific receptors on the surface of host cells.
3. Recall that attachment to host cell receptors is the first step in viral infection, allowing the virus to enter the host cell.
4. Note that degrading host cell membranes, synthesizing viral DNA, and producing energy are functions that occur after attachment or are carried out by other viral or host cell components.
5. Conclude that the primary function of the projections (spikes) is to facilitate attachment to specific host cell receptors, enabling the virus to infect the cell.