Final answer:
Glycoprotein spikes are protein structures found on the capsids of all viruses. They help the virus attach to host cells by binding to viral receptors on the cell's surface.
Step-by-step explanation:
Glycoprotein spikes are protein structures found on the capsids of all viruses. These spikes help the virus attach to host cells by binding to molecules on the cell's surface called viral receptors. For example, the influenza virus uses spikes called hemagglutinin (H) and neuraminidase (N) to attach and enter cells. Glycoprotein spikes play a crucial role in the viral infection process.