Food Biotechnology — page 20 of 34

Food Biotechnology terms

1901. megaDalton (Abbreviation: MDa). One megaDalton is equal to 106 Dalton.
1902. megagametophyte The female gametophyte; the plant that develops from a megaspore.
1903. megaspore The female gametophyte in heterosporous plants. Synonym: macrospore.
1904. Meiosis A special form of cell division in which each daughter cell receives half the amount of DNA as the parent cell.
1905. meiotic analysis The use of patterns of chromosome pairing at meiotic prophase and metaphase to detect relationships between chromosomes, from which can be deduced the…
1906. meiotic drive Any mechanism that causes a particular allele or chromosome to be over-represented in a population of gametes.
1907. meiotic product See: gamete.
1908. melanin (MEH-luh-nin) A pigment that gives color to skin and eyes and helps protect it from damage by ultraviolet light.
1909. melting temperature (Abbreviation: Tm). The temperature at which a double-stranded DNA molecule denatures into separate single strands.
1910. membrane bioreactor A vessel in which cells are cultured on or behind a permeable membrane, which allows the diffusion of nutrients to the cells, but retains the cells…
1911. memory cell Long-lived B cells and T cells that mediate rapid secondary immune responses to a previously encountered antigen.
1912. Mendel's Laws Two laws summarizing Gregor Mendel's theory of inheritance. The Law of Segregation states that each hereditary characteristic is controlled by two…
1913. Mendelian population A natural, interbreeding unit of sexually reproducing plants or animals sharing a common gene pool.
1914. Mendelian segregation Occurs when alleles are inherited according to Mendel's Laws.
1915. mericlinal Refers to a chimera with tissue of one genotype partly surrounded by that of another genotype.
1916. mericloning A propagation method using shoot tips in culture to proliferate multiple buds, which can then be separated, rooted and planted out.
1917. meristele The branch of a stele supplying the leaf.
1918. meristem Undifferentiated but determined plant tissue, in which the cells are capable of active division and differentiation into specialized tissues such as…
1919. meristem culture A tissue culture containing meristematic dome tissue without adjacent leaf primordia or stem tissue.
1920. meristem tip An explant comprising the meristem (meristematic dome) and usually one pair of leaf primordia.
1921. meristem tip culture Cultures derived from meristem tip explants . Used widely to achieve virus elimination and axillary shoot proliferation, less commonly for callus…
1922. meristemoid A localized group of callus cells, characterized by their accumulation of starch, RNA and protein, and giving rise to adventitious shoots or roots.
1923. merozygote Partial zygote produced by a process of partial genetic exchange, such as transformation in bacteria.
1924. mesh bioreactor See: filter bioreactor.
1925. Mesoderm The middle germ layer that forms in the early animal embryo and gives rise to parts such as bone and connective tissue.
1926. mesophile A micro-organism able to grow in the temperature range 20-50 °C; optimal growth often occurs at about 37 °C. See: psychrophile, thermophile.
1927. mesophyll Leaf parenchyma tissue found between epidermal layers.
1928. messenger RNA Abbreviation: mRNA.
1929. Messenger RNA (mRNA) The class of RNA molecules that copies the genetic information from DNA, in the nucleus, and carries it to ribosomes, in the cytoplasm, where it is…
1930. metabolic cell A cell that is not dividing. See: metabolism
1931. metabolism (meh-TA-boh-lih-zum) The total of all chemical changes that take place in a cell or an organism.
1932. metabolite (meh-TA-boh-lite) A substance made or used when the body breaks down food, drugs or chemicals, or its own tissue (for example, fat or muscle tissue).
1933. metabolomics The large-scale study of the full complement of secondary metabolites produced by a given species in all its tissues and growth stages.
1934. metacentric chromosome A chromosome in which the centromere is located in the middle and, consequently, the chromosome arms are of about equal length.
1935. metal affinity chromatography A chromatographic technique, in which a compound interacting with a specific metal ion can be captured by immobilizing the relevant ion on the column's…
1936. metalloenzyme An enzyme which requires the presence of a metal in order to be catalytically active.
1937. Metallothionein A protective protein that binds heavy metals, such as cadmium and lead.
1938. Metaphase Stage of mitosis or meiosis (following prophase and preceding anaphase ) during which the chromosome s, or at least the kinetochores, lie in the central…
1939. metastasis (meh-TAS-tuh-sis) The spread of cancer from one part of the body to another. A tumor formed by cells that have spread is called a "metastatic tumor" or a…
1940. methylation The addition of a methyl group (-CH3) to a molecule, most commonly in the context of DNA where cytosine and, less often, adenine residues can be modified…
1941. MHC Abbreviation for major histocompatibility complex.
1942. Michaelis constant See: Km.
1943. micro-array A large set of cloned DNA molecules immobilized as a compact and orderly pattern of sub-microlitre spots onto a solid matrix (typically a glass slide).
1944. micro-carrier Small particles used as a support material for (particularly mammalian) cells, which are too fragile to be pumped and stirred as bacterial cells are in a…
1945. micro-element A nutritional element required in very small quantities.
1946. micro-encapsulation A process of enclosing a substance in very small sealed capsules from which material is released by heat, solution or other means.
1947. micro-environment A small-scale environment in which the conditions (temperature, humidity, pH etc.
1948. micro-injection The introduction of small amounts of (usually) liquid material (DNA, RNA, enzyme s, cytotoxic agents) into a defined tissue or single cell with a fine…
1949. micro-isolating system Mechanical separation of single cells or protoplasts thus allowing them to proliferate individually.
1950. micro-organism Organism visible only under magnification.
1951. microalgal culture Culture in bioreactors of microalgae (including seaweeds).
1952. Microbe A microorganism.
1953. microbial mat Layered microbial populations, usually growing on the surface of a solid medium or on a membrane.
1954. Microbial mats (biofilms) Layered groups or communities of microbial populations.
1955. microbody A frequently spherical cellular organelle, bound by a single membrane, 20-60 nm in diameter, and containing a variety of enzymes.
1956. microdroplet array (Abbreviation: MDA). A technique used to simultaneously evaluate large numbers of media modifications, employing small quantities of medium into which are…
1957. microfibril Microscopic fibres visible only at the high magnification of the electron microscope.
1958. microgametophyte See: pollen.
1959. micrograft See: shoot-tip graft.
1960. Microinjection A means to introduce a solution of DNA, protein, or other soluble material into a cell using a fine microcapillary pipet.
1961. micronucleus A nucleus, distinct from and smaller than the main nucleus, but lying within the same cell.
1962. micronutrient (MY-kroh-NOO-tree-ent) A substance the body needs in tiny amounts to grow and stay healthy. Examples are vitamins and minerals.
1963. microplast Vesicle produced by subdivision and fragmentation of protoplasts or thin-walled cells.
1964. microprojectile bombardment See: biolistics.
1965. micropropagation Miniaturized in vitro multiplication and/or regeneration of plant material under aseptic and controlled environmental conditions.
1966. micropyle 1. A small opening in the surface of a plant ovule through which the pollen tube passes prior to fertilization. 2.
1967. microsatellite A short sequence of DNA, usually 1 to 4 basepairs (a unit of DNA), that is repeated together in a row along the DNA molecule.
1968. microspore The immature male gametophyte in seed plants; the haploid male cell that ripens into a pollen grain.
1969. microtuber Miniature tuber, produced in tissue culture, which is readily regenerable into a normal tuberous plant.
1970. Microtubule Self-assembling components of the cytoskeleton. Microtubules are cylindrical protein polymers, interconnected by cross-bridging proteins, which…
1971. mid-parent value The average of the phenotypic measure, with respect to a given trait, of the two parents used to generate the population being analysed.
1972. middle lamella A thin exclusively plant membrane separating two adjacent protoplasts and remaining as a distinct cementing layer between adjacent cell walls.
1973. mineralization The conversion of organic compounds into inorganic (mineral) ones. For example, the conversion of ethanol into carbon dioxide and water.
1974. mini-prep A small-scale preparation of plasmid or phage DNA. Used to purify cloned DNA from the DNA of the vector.
1975. Minimal tillage practices Practices that allow farmers to reduce the tilling of the land to conserve topsoil and its nutrients.
1976. minimum effective cell density The cell density below which reproducible cell growth fails. The minimum density is determined by both the source function of the tissue (species…
1977. minimum inoculum size The critical volume of inoculum required to initiate culture growth, due to the diffusive loss of cell materials into the medium.
1978. minisatellite A form of variable number tandem repeats in which the repeat unit size ranges from 10-100 bp. Used for DNA fingerprinting following Southern hybridization.
1979. minituber Small tubers (5-15 mm in diameter) formed on shoot cultures or cuttings of tuber-forming crops, such as potato.
1980. mismatch The occurrence of a non-complementary pairs of bases in a double helix of DNA, e.g. A:C, G:T.
1981. mismatch repair A DNA repair process that corrects mismatched base pairs.
1982. missense mutation A mutation that changes a codon for one amino acid into a codon specifying another amino acid.
1983. mist propagation Application of fine droplets of water to maintain humidity around plantlets or cuttings, which have not yet developed effective roots.
1984. mite Free-living and parasitic arachnids. Infestation of plant crops reduces yield through the destruction of leaf tissue.
1985. Mitochondrial DNA (Abbreviation: mtDNA). A circular DNA found in mitochondria. In mammals, mtDNA makes up less than 1% of the total DNA, but in plants the amount is…
1986. mitochondrion (pl.: mitochondria) Organelle possessing its own DNA which appear in all eukaryotic cells (and never in prokaryotic cells) and produce adenosine…
1987. mitogen A substance that can cause cells to initiate mitosis.
1988. Mitosis (my-TOH-sis) The process by which a single parent cell divides to make two new daughter cells.
1989. mixed bud A bud containing both rudimentary leaves and flowers.
1990. mixoploid Groups of cells with variable (a mix of euploid, aneuploid, polyploid ) chromosome numbers.
1991. mobilization 1. The transfer between bacteria of a non-conjugative plasmid by a conjugative plasmid. 2.
1992. mobilizing function The genes on a plasmid that give it the ability to facilitate the transfer of either a non-conjugative or a conjugative plasmid from one bacterium to…
1993. mode In a frequency distribution, the class having the greatest frequency.
1994. model See Exhibit.
1995. modern biotechnology The application of: a. In vitro nucleic acid techniques, including recombinant deoxyribonucleic acid (DNA ) and direct injection of nucleic acid into…
1996. Modification Any change to the terms of a mortgage loan, including changes to the interest rate, loan balance, or loan term.
1997. modifying gene A gene that affects the expression of some other gene.
1998. MOET Abbreviation for multiple ovulation and embryo transfer.
1999. Molecular biology The study of the biochemical and mo- lecular interactions within living cells.
2000. molecular chaperone See: chaperone.