Science+questions+page+137

Angela Corrao Science page 137 questions 1-3 1. When your immune system overreacts to antigens that are not dangerous to your body is called an allergy. An autoimmune disease is a disease in which the immune system attacks the body’s own cells. The difference between the two are that an autoimmune disease the body attacks it's own cells, and when you have allergies it causes no physical harm to your insides. 2. It is important that immune-system cells be bale to recognize all of the body’s own cells, because other wise your immune system will begin to attack other parts of your body. Such as your joint, which will then cause you to get a disease called arthritis.

3. Occasionally though a cell doesn't respond to the body's regulation and begins dividing at an uncontrolled rate.