| A | B |
|---|
| cell | a membrane-bound structure that is the basic Unit of life |
| cell membrane | the lipid bilayer that forms the outer boundary of the cell |
| cell theory | the theory that all living things are made up of cells, that cells arethe basic units of organisms, and that cells come only from existing cells |
| cell wall | a rigid structure that surrounds the cells of plants, fungi, manyprotists, and most bacteria |
| chloroplast | a plastid containing chlorophyll; the site of photosynthesis |
| chromatin | the DNA and proteins in the nucleus of a nondividing cell |
| chromosome | DNA and protein in a coiled, rod-shaped form that occurs during cell division |
| cilia | short, hair-like organelles that extend from a cell and functions in locomotion or in the movement of substances across the cell surface |
| crista | a fold of the inner membrane of mitochondria |
| cytoplasm | the region of a cell between the cell membrane and the nucleus |
| cytoskeleton | a network of long protein strands in the cytosol that helpsmaintain the shape and size of a eukaryotic cell |
| cytosol | the gelatin-like aqueous fluid that bathes the organelles on the inside ofthe cell membrane |
| endoplasmic reticulum | a system of membranous tubules and sacs ineukaryotic cells that functions as a path along which molecules move from one part of the cell to another |
| eukaryote | a cell that contains a nucleus and membrane-bound organelles |
| flagellum | a hairlike structure made up of microtubules that function in locomotion |
| Golgi apparatus | a system of membranes in eukaryotic cells that modifiesproteins for export by the cell |
| 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 |
| mitochondrion | the organelle that is the site of aerobic respiration in eukaryoticcells |
| nuclear envelope | a double membrane that surrounds the nucleus of aeukaryotic cell |
| nuclear matrix | 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 partiallyassembled; found in most nuclei |
| nucleus | in a eukaryotic cell, the organelle that contains most of the DNA anddirects the cell's activities |
| organelle | one of several formed bodies with a specialized function that issuspended in the cytoplasm and found in eukaryotic cells |
| peripheral protein | a protein attached to the interior or exterior surface of the cell membrane |
| prokaryote | a unicellular organism that lacks a nucleus and membrane-boundorganelles |
| protozoan | a single-celled, eukaryotic protist that is able to moveindependently |
| ribosome | an organelle that functions in the synthesis of proteins |
| rough endoplasmic reticulum | the portion of the endoplasmic reticulum thatcontains attached ribosomes |
| selectively permeable membrane | a membrane that keeps out some moleculesbut allows others to pass through |
| smooth endoplasmic reticulum | the portion of the endoplasmic reticulum that lacks attached ribosomes |
| vacuole | a fluid-filled organelle that stores enzymes or metabolic wastes in a plant cell |
