Biotechnology and Genetics — page 23 of 40

3,925 terms including subtopics (0 terms filed directly here)

Subtopics

Biotechnology and Genetics terms

  1. Maternal gene product A product in the male organism of a gene from the X chromosome.
  2. maternal inheritance Inheritance controlled by non-nuclear genes (e.g. mitochrondria, chloroplast ) that are transmitted only through the female line.
  3. matric potential A water potential component, always of negative value, resulting from the presence of solid (often finely divided) surfaces; primarily responsible for…
  4. maturation The formation of gametes or spores.
  5. MCS Abbreviation for multiple cloning site. See: polylinker.
  6. MDA Abbreviation for multiple drop array. See: microdroplet array.
  7. Mean A statistics term. The average value in a set of measurements. The mean is the sum of a set of numbers divided by how many numbers are in the set.
  8. Media Any organization in the business of informing the public with news or commentary.
  9. median A statistics term. The middle value in a set of measurements.
  10. medium (pl.: media) 1. In plant tissue culture, a term for the liquid or solid formulation upon which plant cells, tissues or organs develop.
  11. medium formulation In tissue culture, the particular constituents for the culture medium, commonly comprising macro- and micro-elements, vitamins, plant hormones, and a…
  12. mega yeast artificial chromosome A yeast artificial chromosome (YAC) which can carry particularly large inserts (up to 1Mbp) - standard YACs typically carry inserts of up to 500kbp.
  13. megabase (Abbreviation: Mb). A length of DNA consisting of 106 bases.
  14. Megabase (Mb) Unit of length for DNA fragments equal to 1 million nucleotides and roughly equal to 1 cM. See also: centimorgan
  15. Megabase cloning The cloning of very large DNA fragments. (See Cloning.)
  16. megaDalton (Abbreviation: MDa). One megaDalton is equal to 106 Dalton.
  17. megagametophyte The female gametophyte; the plant that develops from a megaspore.
  18. megaspore The female gametophyte in heterosporous plants. Synonym: macrospore.
  19. Meiosis A special form of cell division in which each daughter cell receives half the amount of DNA as the parent cell.
  20. 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…
  21. meiotic drive Any mechanism that causes a particular allele or chromosome to be over-represented in a population of gametes.
  22. meiotic product See: gamete.
  23. melanin (MEH-luh-nin) A pigment that gives color to skin and eyes and helps protect it from damage by ultraviolet light.
  24. Melanocyte (mel-AN-o-site) A cell in the skin and eyes that produces and contains the pigment called melanin.
  25. melanoma (MEH-luh-NOH-muh) A form of cancer that begins in melanocytes (cells that make the pigment melanin).
  26. melting temperature (Abbreviation: Tm). The temperature at which a double-stranded DNA molecule denatures into separate single strands.
  27. 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…
  28. memory Data storage in the form of chips, or the actual chips used to hold data; storage is used to describe memory that exists on tapes or discs.
  29. memory cell Long-lived B cells and T cells that mediate rapid secondary immune responses to a previously encountered antigen.
  30. Memory cells A subset of antigen-specific T or B cells that "recall" prior exposure to an antigen and respond quickly without the need to be activated again by CD4…
  31. 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…
  32. Mendel, Johann (Gregor) Austrian biologist, born in 1822 and died in 1884, who laid the foundations for the science of genetics.
  33. Mendelian inheritance Manner in which genes and traits are passed from parents to children. Examples of Mendelian inheritance include autosomal dominant, autosomal recessive…
  34. Mendelian population A natural, interbreeding unit of sexually reproducing plants or animals sharing a common gene pool.
  35. Mendelian segregation Occurs when alleles are inherited according to Mendel's Laws.
  36. mericlinal Refers to a chimera with tissue of one genotype partly surrounded by that of another genotype.
  37. mericloning A propagation method using shoot tips in culture to proliferate multiple buds, which can then be separated, rooted and planted out.
  38. meristele The branch of a stele supplying the leaf.
  39. meristem Undifferentiated but determined plant tissue, in which the cells are capable of active division and differentiation into specialized tissues such as…
  40. meristem culture A tissue culture containing meristematic dome tissue without adjacent leaf primordia or stem tissue.
  41. meristem tip An explant comprising the meristem (meristematic dome) and usually one pair of leaf primordia.
  42. meristem tip culture Cultures derived from meristem tip explants . Used widely to achieve virus elimination and axillary shoot proliferation, less commonly for callus…
  43. meristemoid A localized group of callus cells, characterized by their accumulation of starch, RNA and protein, and giving rise to adventitious shoots or roots.
  44. merozygote Partial zygote produced by a process of partial genetic exchange, such as transformation in bacteria.
  45. Mesemchymal stem cell Also known as bone marrow stromal cells, mesenchymal stem cells are rare cells, mainly found in the bone marrow, that can give rise to a large number of…
  46. Mesenchymal stem cells Cells from the immature embryonic connective tissue. A number of cell types come from mesenchymal stem cells, including chondrocytes, which produce…
  47. Mesenchymal stem cells (MSCs) Cells from the immature embryonic connective tissue. A number of cell types come from mesenchymal stem cells, including chondrocytes, which produce…
  48. mesh bioreactor See: filter bioreactor.
  49. Mesoderm The middle germ layer that forms in the early animal embryo and gives rise to parts such as bone and connective tissue.
  50. 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.
  51. mesophyll Leaf parenchyma tissue found between epidermal layers.
  52. messenger RNA Abbreviation: mRNA.
  53. 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…
  54. metabolic cell A cell that is not dividing. See: metabolism
  55. metabolism (meh-TA-boh-lih-zum) The total of all chemical changes that take place in a cell or an organism.
  56. 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).
  57. metabolomics The large-scale study of the full complement of secondary metabolites produced by a given species in all its tissues and growth stages.
  58. metacentric chromosome A chromosome in which the centromere is located in the middle and, consequently, the chromosome arms are of about equal length.
  59. Metachromatic leukodystrophy A heritable metabolic disorder, usually of infancy, characterized by myelin loss and other abnormalities of the white matter of the nervous system…
  60. 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…
  61. metalloenzyme An enzyme which requires the presence of a metal in order to be catalytically active.
  62. Metallothionein A protective protein that binds heavy metals, such as cadmium and lead.
  63. 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…
  64. 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…
  65. 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…
  66. MHC Abbreviation for major histocompatibility complex.
  67. Michaelis constant See: Km.
  68. 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).
  69. 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…
  70. micro-element A nutritional element required in very small quantities.
  71. micro-encapsulation A process of enclosing a substance in very small sealed capsules from which material is released by heat, solution or other means.
  72. micro-environment A small-scale environment in which the conditions (temperature, humidity, pH etc.
  73. 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…
  74. micro-isolating system Mechanical separation of single cells or protoplasts thus allowing them to proliferate individually.
  75. micro-organism Organism visible only under magnification.
  76. microalgal culture Culture in bioreactors of microalgae (including seaweeds).
  77. Microarray Sets of miniaturized chemical reaction areas that may also be used to test DNA fragments, antibodies, or proteins.
  78. microarray technology A new way of studying how large numbers of genes interact with each other and how a cell's regulatory networks control vast batteries of genes…
  79. Microbe A microorganism.
  80. Microbial genetics The study of genes and gene function in bacteria, archaea, and other microorganisms.
  81. microbial mat Layered microbial populations, usually growing on the surface of a solid medium or on a membrane.
  82. Microbial mats (biofilms) Layered groups or communities of microbial populations.
  83. microbody A frequently spherical cellular organelle, bound by a single membrane, 20-60 nm in diameter, and containing a variety of enzymes.
  84. microdroplet array (Abbreviation: MDA). A technique used to simultaneously evaluate large numbers of media modifications, employing small quantities of medium into which are…
  85. Microenvironment The molecules and compounds such as nutrients and growth factors in the fluid surrounding a cell in an organism or in the laboratory, which play an…
  86. microfibril Microscopic fibres visible only at the high magnification of the electron microscope.
  87. microgametophyte See: pollen.
  88. micrograft See: shoot-tip graft.
  89. Microinjection A means to introduce a solution of DNA, protein, or other soluble material into a cell using a fine microcapillary pipet.
  90. Micronuclei Chromosome fragments that are not incorporated into the nucleus at cell division.
  91. micronucleus A nucleus, distinct from and smaller than the main nucleus, but lying within the same cell.
  92. micronutrient (MY-kroh-NOO-tree-ent) A substance the body needs in tiny amounts to grow and stay healthy. Examples are vitamins and minerals.
  93. microplast Vesicle produced by subdivision and fragmentation of protoplasts or thin-walled cells.
  94. microprojectile bombardment See: biolistics.
  95. micropropagation Miniaturized in vitro multiplication and/or regeneration of plant material under aseptic and controlled environmental conditions.
  96. micropyle 1. A small opening in the surface of a plant ovule through which the pollen tube passes prior to fertilization. 2.
  97. 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.
  98. microspore The immature male gametophyte in seed plants; the haploid male cell that ripens into a pollen grain.
  99. microtuber Miniature tuber, produced in tissue culture, which is readily regenerable into a normal tuberous plant.
  100. Microtubule Self-assembling components of the cytoskeleton. Microtubules are cylindrical protein polymers, interconnected by cross-bridging proteins, which…