| A | B |
|---|
| cell | basic unit of structure |
| cell membrane | thin covering that encloses a cell |
| nucleus | organell that controls all of a cell's activities |
| cytoplasm | jelly-like substance containing many chemicals that keep a cell functioning |
| diffusion | process by which many materials move in and out of cells |
| osmosis | the diffusion of water and dissolved materials through cell membranes |
| tissue | cells that work together to perform a specific function |
| organ | tissues that work together to form a specific function |
| system | organs that work together to perform a function |
| capillaries | the smallest blood vessels |
| alveoli | tiny air sacs located at the ends of bronchi in the lungs |
| villi | projections sticking into the small intestines |
| nephrons | tubes inside the kidneys where urea and water diffuse from the blood |
| bone marrow | a connective tissue that produces red and white blood cells |
| joints | where bones meet and are attached to each other and to the muscles |
| tendons | tough bands of connective tissue that attach muscles to bones |
| ligaments | bands of connective tissue that holds the skeleton together |
| neuron | a specialized cell that can receive information and transmit it to other cells |
| receptors | nerve cells that detect conditions in the body's environment. |
