The function of spike proteins is to imitate a protein your cells take in to allow the virus access to the nucleus.
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.
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.
A part of the viral envelope/ capsid which are proteins is known as spikes. They help evade the defenses of the host cell are obtained from their protein.
endocytosis
It function is to make mRNA and acts as a jet preppeled motor to help the virus move.
The collar function in a virus is used to create mRNA. It uses this function to move since it creates a bit of a propeller effect.
it does not have a life function
the nucleic acid and capsid of virus are in the head and they help also grow the virus
The function is to allow "docking" with the host cell.
the protective protein coating
Reproduction.