| A | B |
|---|
| chloroplast | a plastid containing chlorophyll; the site of photosynthesis |
| cilium | a short, hairlike organelle that extends from a cell and functions in locomotion or in the movement of substances across the cell surface |
| chromatin | the DNA and proteins in the nucleus of a nondividng cell |
| chromosome | DNA and protein in a coiled, rod-shaped form that occurs during cell division |
| flagellum | a hairlike structure made up of microtubules that function in locomotion |
| integral protein | a protein imbedded in the bilayer of the cell membrane |
| microfilament | a polymer chain of the protein actin; the smallest strand in the cytoskeleton |
| microtubule | a hollow tube of protein that constitutes the largest strand in the cytoskeleton |
| nuclear envelope | a double membrane that surrounds the nucleus of a eukaryotic cell |
| nuclear matrix | nucleoplasm; the nuclear skeleton, a shape-maintaining protein |
| nuclear pore | a small hole in the nuclear envelope through which substances pass between the nucleus and the cytoplasm |
| nucleolus | the structure in which ribosomes are synthesized and partially assembled; found in most nuclei |
| peripheral protein | a protein attached to the interior or exterior surface of the cell membrane |
| selectively permeable membrane | a membrane that keeps out some molecules but allows others to pass through |
| spindle fiber | one of the microtubules that extend across a dividing eukaryotic cell; assisits in the movement of chromosomes |
| thylakoid | a flattened, membranous sac inside a chloroplast; contains most of the components involved in the light reactions of photosynthesis |
| colonial organism | a collection of genetically identical cells that live together in a closely connected group |
