Because HIV is a virus. Viruses have spikes because it is their way of reproducing.
They are not spikes - they are arms. They use these 'arms' to catch other cells to mutate them or eat them.
Spikes are proteins that are part of the viral capsid/envelope (depending on if the virus is a naked virus or not). It helps with attachment to the host cell. They are derived from their host cell's own proteins (but are not the same as their hosts), and can help in evading the host cell's defenses.
The function of spike proteins is to imitate a protein your cells take in to allow the virus access to the nucleus.
Spikes on viruses are made up of proteins that are used to attach the virus to host cells. These proteins play a critical role in allowing the virus to enter and infect host cells by binding to specific receptors on the cell membrane.
To protect the sponge's body.
A virus that uses both boot-sector and executable functions is a multipartite virus. This type of virus attacks a variety of platforms, and continually re-infects each platform until it is removed.
The stage of viral reproduction that takes place when the spikes of the virus bind to a specific receptor molecule on the surface of a host cell is known as attachment or adsorption. This step is crucial for the virus to gain entry into the host cell and initiate the infection process.
BIOS virus detection functions
The three are a capsid, envelope and spikes. The envelope is optional.
The virus attaches to the host cell, it takes over the functions of the host cell, and it eventually destroys it. If there was no host cell, the virus would die.
The spikes you are referring to I am assuming concern viruses. They are located on the envelope surrounding the capsid, typically made up of the host cell material. The spikes themselves are of protein and match with receptors on the host cell. This is kind of like a key to a door. The virus sheds the envelope when entering the host cell, then sheds the capsid, releasing the nucleic acid (DNA/RNA) causing a viral infection to occur.