| A | B |
|---|
| excretion | the removal of cellular wastes; liquids and gases |
| homeostasis | the ability of an organism to maintain a stable internal environment even when the external environment changes |
| hormone | chemical messengers produced in the endocrine glands, proteins |
| immunity | the body's ability to destroy pathogens before they cause disease |
| inorganic | a type of molecule that does not contain both carbon and hydrogen but can contain any other combination of elements |
| metabolism | all the chemical reactions that occur within the cells of an organism |
| mitochondria | pod-shaped organelles that contain enzymes used to extract energy from nutrients, site of cellular respiration, "powerhouse of the cell" |
| nucleus | a large structure within a cell that controls the cell's metabolism and stores genetic information (chromosomes and DNA) |
| organ | a body structure made of different kinds of tissues combined to perform a specific function |
| organ system | several organs that work together to perform a major function in the body |
| organelle | a structure within the cell that carries out a specific function |
