| cell nucleolus | Within most types of eukaryotic cell nucleus, a distinct region, not delimited by a membrane, in which some species of rrna (RNA, ribosomal) are synthesised and assembled into ribonucleoprotein subunits of ribosomes. In the nucleolus rrna is transcribed from a nucleolar organiser, i.e., a group of tandemly repeated chromosomal genes which encode rrna and which are transcribed by RNA polymerase I. (12 Dec 1998) |
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| granular component of nucleolus | Area of nucleolus that appears granular in the electron microscope and contains 15nm diameter particles that are maturing ribosomes. In contrast to the pale staining and fibrillar areas. (18 Nov 1997) |
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| chromatin nucleolus | <cell biology> The central portion of a cells nucleus that typically contains a glob of heterochromatin. Origin: Gr. Soma = body (09 Oct 1997) |
| nucleolus | <cell biology> A small dense body (sub organelle) within the nucleus of eukaryotic cells, visible by phase contrast and interference microscopy in live cells throughout interphase. Contains RNA and protein and is the site of synthesis of ribosomal RNA. The nucleolus surrounds a region of one or more chromosomes (the nucleolar organiser) in which are repeated copies of the DNA coding for ribosomal RNA. (18 Nov 1997) |
| nucleolus organiser | <molecular biology> Loop of DNA that has multiple copies of rRNA genes. See: nucleolus. (18 Nov 1997) |
| nucleolus organiser region | The chromosome region which is active in nucleolus formation and which functions in the synthesis of ribosomal RNA. (12 Dec 1998) |
| false nucleolus | <cell biology> The central portion of a cells nucleus that typically contains a glob of heterochromatin. Origin: Gr. Soma = body (09 Oct 1997) |
| T-cell-rich, B-cell lymphoma | <tumour> A B-cell lymphoma in which more than 90% of the cells are of T-cell origin, masking the large cells that form the neoplastic B-cell component. See: adult T-cell lymphoma. (05 Mar 2000) |
| absorption cell | A small glass chamber with parallel sides, in which absorption spectra of solutions can be obtained. (05 Mar 2000) |
| acid cell | One of the cell's of the gastric glands; it lies upon the basement membrane, covered by the chief cell's, and secretes hydrochloric acid that reaches the lumen of the gland through fine intracellular and intercellular canals (canaliculi). Synonym: acid cell, oxyntic cell. (05 Mar 2000) |
| acidophil cell | A cell whose cytoplasm or its granules stain with acid dyes. (05 Mar 2000) |
| acinar cell | Any secreting cell lining an acinus, especially applied to the cell's of the pancreas that furnish pancreatic juice and enzymes to distinguish them from the cell's of ducts and the islets of Langerhans. Synonym: acinous cell. (05 Mar 2000) |
| acinar cell tumour | A solid and cystic tumour of the pancreas, occurring in young women; tumour cells contain zymogen granules. (05 Mar 2000) |
| acinic cell adenocarcinoma | <tumour> An adenocarcinoma arising from secreting cells of a racemose gland, particularly the salivary glands. Synonym: acinar carcinoma, acinic cell carcinoma, acinose carcinoma, acinous carcinoma. (05 Mar 2000) |
| acinic cell carcinoma | <tumour> An adenocarcinoma arising from secreting cells of a racemose gland, particularly the salivary glands. Synonym: acinar carcinoma, acinic cell carcinoma, acinose carcinoma, acinous carcinoma. (05 Mar 2000) |
| acinous cell | Any secreting cell lining an acinus, especially applied to the cell's of the pancreas that furnish pancreatic juice and enzymes to distinguish them from the cell's of ducts and the islets of Langerhans. Synonym: acinous cell. (05 Mar 2000) |