You would go to an ophthalmologist (eye doctor).
cells have many structures inside of them called organelles. these organelles are like the organs in a human and they help the cell stay alive. each organelle has it's own specific function to help the cell survive. the nucleus of a eukaryotic cell directs the cell's activities and stores DNA.
That is true it was for a virus
This is how vaccines are used. You introduce the antibodies in a vaccine so the person builds up an immunity and never develops the disease
