Some allergic reactions are caused by the body's immune responses to
usually harmless environmental substances. Sometimes the immune system
may attack some of the body's own cells.
NSES Content Standard C
Life Science: Structure and function in living systems Grades 5-8, page 157 Disease is a breakdown in structures or functions of an organism. Some diseases are the result of intrinsic failures of the system. Others are the result of damage by infection by other organisms. |