10-13 years normally.
Hope this helps, and good luck!
1) I would choose white blood cells since their main job is to fight infection (Something that does not belong as a part of the body) But since their is several types of white blood cells the ones too look out for would be the Neutrophils since they kill bacteria by ingesting them.
2) It would be a Neutrophils blood cell. They are 12-14 µm diameter, and so look bigger than the surrounding red blood cells. There is a single nucleus, which is multilobed, and can have between 2 and 5 lobes.
3)You would also have to watch out for: Granulocytes – cells which contain granules which contain chemicals that are used to kill bacteria and viruses Lymphocytes- cells which attack most of the bacterial and viral infections in our bodiesMonocytes - cells which become macrophages, large cells that engulf harmful particles in our bodies.
C. Skin
Because it's the outer layer of your body that protects everything
One example is to run around your neighborhood
