| Name: | notochord |
|---|---|
| Synonyms: | notocord |
| Definition: | Rod-like principal supportive element of the embryo and larva, present in the midline just ventral to the neural tube, and differentiating during the segmentation period to form large vacuolated epithelial cells and a surrounding sheath of fibrous and elastic layers. Layering of the sheath may differ in structure, thickness and development among groups; in cypriniforms there are actually three very thin layers to the sheath. A functional, well developed notochord is present throughout life in certain basal fish groups but not in cypriniforms. |
| Ontology: | Anatomy Ontology [ZFA:0000135] |
| Name: | centriole |
|---|---|
| Synonyms: | daughter centriole, mother centriole |
| Definition: | A cellular organelle, found close to the nucleus in many eukaryotic cells, consisting of a small cylinder with microtubular walls, 300-500 nm long and 150-250 nm in diameter. It contains nine short, parallel, peripheral microtubular fibrils, each fibril consisting of one complete microtubule fused to two incomplete microtubules. Cells usually have two centrioles, lying at right angles to each other. At division, each pair of centrioles generates another pair and the twin pairs form the pole of the mitotic spindle. |
| Ontology: | GO: Cellular Component [GO:0005814] QuickGO AmiGO |