Food moves through your GI tract by a process called peristalsis. The large, hollow organs of your GI tract contain a layer of muscle that enables their walls to move.
Answer: 2. Precipitation
Explanation:
Aerobic cellular respiration requores oxygen. Photosynthesis does, as well.
A doctor need to study chemistry: To know and understand the chemicals processes of matter in the body work which is for example insulin, DNA etc. and to study of all processes in a living organism. The three reasons to study chemistry is because chemistry can be useful in clearing up the natural world, preparing people for career opportunities and producing informed citizens. Some outcomes of modern research in chemistry can lead to technologies that aim to benefit the environment, preserve and produce energy, progress human life and multiply our knowledge of the universe. To help the citizen be a more informed citizen is to let them know how things work makes better decisions and use them better
Lack of antibodies because thats the stuff to fight things away