Term | Definition |
Centriole | an organelle that is composed of two short microtubules at right angles to each other and that has an active role in mitosis |
Chromosome | in a eukaryotic cell, one of the structures in the nucleus that are made up of DNA and protein; in a prokaryotic cell, the main ring of DNA |
Cilium | a hairlike structure arranged in tightly packed rows that projects from the surface of some cells |
Cytoskeleton | the cytoplasmic network of protein filaments and tubes that plays an essential role in cell movement, shape, and division |
Endoplasmic Reticulum | a system of membranes that is found in a cell's cytoplasm and that assists in the production, processing, and transport of proteins and in the production of lipids |
Flagellum | a long, hairlike structure that grows out of a cell and enables the cell to move |
Golgi apparatus | cell organelle that helps make and package materials to be transported out of the cell |
Lysosome | a cell organelle that contains digestive enzymes and that buds from the Golgi apparatus |
Microfilament | a fiber found inside eukaryotic cells that is composed mainly of the protein actin and that has a role in cell structure and movement |
Microtubule | one of the small, tubular fibers composed of the protein tubulin that are found in the cytoplasm of eukaryotic cells, that compose the cytoskeleton, and that play a role in cell structure and movement |
Mitochondrion | in eukaryotic cells, the cell organelle that is surrounded by two membranes and that is the site of cellular respiration, which produces ATP |
Nuclear envelope | the double membrane that surrounds the nucleus of a eukaryotic cell |
Nucleolus | the part of the eukaryotic nucleus where ribosomal RNA is synthesized |
Phospholipid bilayer | a double layer of phospholipids that makes up plasma and organelle membranes |
Ribosome | a cell organelle composed of RNA and protein; the site of protein synthesis |