Antibodies bind to the antigens on the surface of disease agents. If some sort of fluorescent tag is added to the antibody it would make the disease agent be identifiable either under a microscope or with other Instruments because it would bind to the antigens on the surface of the disease agents and make them glow a certain color. I hope that this is the answer that you were looking for and it has helped you.
The answer is C because plants and animals need nutrients to life
Answer: a). growth
Sleep is a necessary biological activity shown by most of the living creatures. It is the primary activity of the brain. During sleep the blood supply to the muscles increases, the energy of the body gets restored, repair and tissue and growth takes place. Important hormones are released for the process of growth and development.
Therefore, sleep is necessary for growth is a correct option.