| division septum | <cell biology> The cell wall that forms between daughter cells at the end of mitosis in plant cells or just before separation in bacteria. (18 Nov 1997) |
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| indirect nuclear division | <cell biology> A method of indirect division of a cell, consisting of a complex of various processes, by means of which the two daughter nuclei normally receive identical complements of the number of chromosomes characteristic of the somatic cells of the species. Mitosis, the process by which the body grows and replaces cells, is divided into four phases. 1. Prophase: formation of paired chromosomes, disappearance of nuclear membrane, appearance of the achromatic spindle, formation of polar bodies. 2. Metaphase: arrangement of chromosomes in the equatorial plane of the central spindle to form the monaster. Chromosomes separate into exactly similar halves. 3. Anaphase: the two groups of daughter chromosomes separate and move along the fibres of the central spindle, each toward one of the asters, forming the diaster. 4. Telophase: the daughter chromosomes resolve themselves into a reticulum and the daughter nuclei are formed, the cytoplasm divides, forming two complete daughter cells. NOTE: the term mitosis is used interchangeably with cell division, but strictly speaking it refers to nuclear division, whereas cytokinesis refers to division of the cytoplasm. In some cells, as in many fungi and the fertilized eggs of many insects, nuclear division occurs within the cell unaccompanied by division of the cytoplasm and formation of daughter cells. (13 Nov 1997) |
| equatorial division | Nuclear division in which each chromosome divides equally. (05 Mar 2000) |
| first meiotic division | The first of two consecutive divisions of the nucleus of an eukaryotic cell during the process of meiosis. It includes the following stages of meiosis: prophase I, metaphase I, anaphase I, and telophase I. (09 Oct 1997) |
| acetyl reduction assay | <investigation> A technique for measuring the nitrogen fixation activity in photosynthetic organisms. It uses a flame ionisation detector and a gas chromatography apparatus to determine the reduction of acetylene to ethylene by the enzyme nitrogenase. (06 May 1997) |
| reduction | <orthopaedics, surgery> The correction of a fracture, dislocation or hernia. (18 Nov 1997) |
| reduction deformity | Congenital absence or attenuation of one or more body parts; usually of the limbs or limb components. (05 Mar 2000) |
| reduction en masse | Reduction of hernial sac and contents, so that intestinal obstruction is still present. (05 Mar 2000) |
| reduction mammaplasty | Plastic surgery of the breast to reduce its size and (frequently) to improve its shape and position. (05 Mar 2000) |
| reduction nucleus | A nucleus that degenerates in the cell during the changes incident to fertilization. (05 Mar 2000) |
| reduction of chromosomes | The process during meiosis whereby one member of each homologous pair of chromosomes is distributed to a sperm or ovum; the diploid set of chromosomes (46 in humans) is thus reduced to the haploid set in each gamete; union of the sperm and ovum then restores the diploid or somatic number in the one-cell zygote. (05 Mar 2000) |
| reduction phase | The stage of nuclear changes in the sexual cells during which reduction of the chromosomes takes place; it embraces the cell generations of the spermatocytes and oocytes. Synonym: reduction phase. (05 Mar 2000) |
| reduction potential | The inherent tendency of a compound to act as an electron donor or an electron acceptor. Measured in volts. (09 Oct 1997) |
| risk reduction | Techniques used to reduce your chances of getting a certain cancer. For example: reducing your dietary fat may help prevent breast cancer. (09 Oct 1997) |
| closed reduction | The physical manipulation of a joint or bone externally (without making a surgical incision) to affect a joint relocation or more proper anatomic alignment of broken bone fragments. Closed reductions are often performed using intravenous analgesics, local anaesthetic nerve blocks or regional anaesthesia. (27 Sep 1997) |