Antibody - A substance made by the blood that destroys or weakens germs. Antibodies help protect the body against certain diseases. Appendix - A thin growth shaped like a bag or pouch. It is attached to the large intestine. Bacteria - Very tiny plants that are so small they can only be seen through a powerful microscope.
Some bacteria cause disease, but others are helpful.
Boil - A red swelling beneath the skin. A boil is full of pus and hurts. It is caused by infection. When you have bronchitis you have a bad cough. Cancer - A disease in which a cell or group of cells begin to divide and grow faster than is normal.