| A | B |
|---|
| Cells | the basic units of structure and function in living things |
| Prokaryotic cells | cells lacking distinct membrane-bound structures |
| Eukaryotic cells | cells containing membrane bound nuclei |
| Nucleus | in a Eukaryotic cell, a large, membrane-enclosed organelle that contains the cells DNA; in an atom, containing protons and neutrons |
| Organelles | the specialized structures in the cytoplasm of cells that carry out specific functions |
| Cell wall | the rigid structures that enclose the cells of plants and various microorganisms; often composed of polysaccharides |
| Cell membrane | the structure that enclose the interior of a cell and controls the passage of materials into and out of the plasma |
| Selectively permeable membrane | a characteristic of a cell membrane that allows some substances to pass freely through the membrane, while others can pass through to a slight extent or not at all |
| Nucleoli | dense, granular bodies that are found in the nucleus of cells and are a site of RNA productions |
| Cytoplasm | the watery material between the nucleus and the cell membrane of a cell |
| Endoplasmic reticulum | a system of fluid-filled canals enclosed by membranes |
| Ribosomes | organelles that are the sites of protein synthesis in cells |
| Golgie bodies | organelles consisting of stacks of membranes forming flattened sacs in the cytoplasm, which serves as packaging centers of the cell |
| Lysosomes | the small, saclike structures surrounded by single membranes and containing strong digestive hydrolytic enzymes |
| Mitochondria | an oval membrane-enclosed organelle in which most of the reactions of cellular respiration occur, site where energy is released in the cell |
| Microtubules | the long, cylindrical organelles that make up cilia and flagella |
| Centrioles | cylindrical organelles found near the nucleus in animal cells that are involved in mitosis, cell division |
| Cilia | short, hair like organelles at the surface of a cell, with the capacity for movement |
| Flagella | long, hair like organelles at the surface of a cell, with the capacity for movement |
| Vacuoles | a membrane-enclosed, fluid-filled cavity in the cell |
