Biotechnology and Genetics terms starting with M

271 terms

M13 A single-stranded DNA bacteriophage used as a vector for DNA sequencing.
M13 strand The single-stranded DNA molecule that is present in the infective form of bacteriophage M13.
MAAP Abbreviation for multiple arbitrary amplicon profiling.
MAB Abbreviation for monoclonal antibody.
macerate To disintegrate tissue to disrupt cells. Commonly achieved via mechanical shearing, plasmolysis or enzymatic cell wall degradation.
macromolecule Any high molecular weight molecule. Often used as a synonym for polymers.
macronutrient A major chemical element essential for normal growth and development. In tissue culture media, macronutrients are those required in concentrations above 0.
macrophage A type of white blood cell that surrounds and kills microorganisms, removes dead cells, and stimulates the action of other immune system cells.
macropropagation Production of plant clones from growing parts.
Macrorestriction map Map depicting the order of and distance between sites at which restriction enzymes cleave chromosomes.
macrospore See: megaspore.
mad cow disease Colloquial term for bovine spongiform encephalopathy. See proteinaceous infectious particle
MADS box A highly conserved DNA sequence motif found in a large family of transcription factors, most of which play important roles in developmental processes.
Magenta Used in four color printing. Reflects blue & red and absorbs green.
major histocompatibility antigen A cell-surface protein or glycoprotein that allows the immune system to distinguish foreign or "non-self" from "self". A better term is histoglobulin.
major histocompatibility complex (Abbreviation: MHC). The large cluster of genes that encode the major histocompatibility antigens in mammals.
Major histocompatibility complex (MHC) A group of genes that code for cell-surface histocompatibility antigens. These antigens are the primary reason why organ and tissue transplants from…
malformation A structural defect inherited in an organ or part of an organ that results from abnormal fetal development. See also syndrome
Malignant (muh-LIG-nunt) Cancerous. Malignant tumors can invade and destroy nearby tissue and spread to other parts of the body.
malt extract A mixture of organic compounds prepared from malt, used as a culture medium additive.
malting Enzymatic reduction of starch to sugars in germinating grain, used in brewing.
mammary gland Glandular organ located on the chest. The mammary gland is made up of connective tissue, fat, and tissue that contains the glands that can make milk.
management of farm animal genetic resources The sum total of technical, policy and logistical operations involved in understanding (characterization), using and developing (utilization), maintaining…
mannitol (MA-nih-TOL) A drug used to decrease swelling of the brain and to treat kidney failure.
mannose A hexose component of many polysaccharides, occasionally used as a carbohydrate source in plant tissue culture media.
MAP 1. verb: to determine the relative positions of loci (genes or DNA sequences) on a chromosome.
map distance The standard measure of genetic distance between loci, expressed in centiMorgans (cM) or map units .
map unit One centiMorgan (1 cM) See: map distance; crossing-over unit.
mapping Determining the physical location of a gene or genetic marker on a chromosome. (See Continuous map, Genetic map, Physical map.)
mapping function A mathematical expression relating observed recombination fraction to map distance.
Mapping population The group of related organisms used in constructing a genetic map.
mariculture See: aquaculture.
marker A diagnostic indication that disease may develop.
marker gene A gene of known function or known location, used for marker-assisted selection or genetic studies.
marker peptide A portion of fusion protein that facilitates its identification or purification.
marker-assisted introgression The use of DNA markers to increase the speed and efficiency of introgression of a new allele(s) or gene(s) into a breeding population.
marker-assisted selection (Abbreviation: MAS). The use of DNA markers to improve response to selection in a population.
MAS Abbreviation for marker-assisted selection.
mass selection As practised in plant and animal breeding, the selection ofa number of individuals, on the basis of their individual phenotypes, to interbreed to form the…
Mass spectrometry this technique can be used to both measure and analyze molecules under study. It involves introducing enough energy into a target molecule to cause its…
Mast cell A type of white blood cell.
maternal effect An effect attributable to a genetic contribution of the female parent of the individual being evaluated.
Maternal gene product A product in the male organism of a gene from the X chromosome.
maternal inheritance Inheritance controlled by non-nuclear genes (e.g. mitochrondria, chloroplast ) that are transmitted only through the female line.
matric potential A water potential component, always of negative value, resulting from the presence of solid (often finely divided) surfaces; primarily responsible for…
maturation The formation of gametes or spores.
MCS Abbreviation for multiple cloning site. See: polylinker.
MDA Abbreviation for multiple drop array. See: microdroplet array.
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.
Media Any organization in the business of informing the public with news or commentary.
median A statistics term. The middle value in a set of measurements.
medium (pl.: media) 1. In plant tissue culture, a term for the liquid or solid formulation upon which plant cells, tissues or organs develop.
medium formulation In tissue culture, the particular constituents for the culture medium, commonly comprising macro- and micro-elements, vitamins, plant hormones, and a…
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.
megabase (Abbreviation: Mb). A length of DNA consisting of 106 bases.
Megabase (Mb) Unit of length for DNA fragments equal to 1 million nucleotides and roughly equal to 1 cM. See also: centimorgan
Megabase cloning The cloning of very large DNA fragments. (See Cloning.)
megaDalton (Abbreviation: MDa). One megaDalton is equal to 106 Dalton.
megagametophyte The female gametophyte; the plant that develops from a megaspore.
megaspore The female gametophyte in heterosporous plants. Synonym: macrospore.
Meiosis A special form of cell division in which each daughter cell receives half the amount of DNA as the parent cell.
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…
meiotic drive Any mechanism that causes a particular allele or chromosome to be over-represented in a population of gametes.
meiotic product See: gamete.
melanin (MEH-luh-nin) A pigment that gives color to skin and eyes and helps protect it from damage by ultraviolet light.
Melanocyte (mel-AN-o-site) A cell in the skin and eyes that produces and contains the pigment called melanin.
melanoma (MEH-luh-NOH-muh) A form of cancer that begins in melanocytes (cells that make the pigment melanin).
melting temperature (Abbreviation: Tm). The temperature at which a double-stranded DNA molecule denatures into separate single strands.
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…
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.
memory cell Long-lived B cells and T cells that mediate rapid secondary immune responses to a previously encountered antigen.
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…
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…
Mendel, Johann (Gregor) Austrian biologist, born in 1822 and died in 1884, who laid the foundations for the science of genetics.
Mendelian inheritance Manner in which genes and traits are passed from parents to children. Examples of Mendelian inheritance include autosomal dominant, autosomal recessive…
Mendelian population A natural, interbreeding unit of sexually reproducing plants or animals sharing a common gene pool.
Mendelian segregation Occurs when alleles are inherited according to Mendel's Laws.
mericlinal Refers to a chimera with tissue of one genotype partly surrounded by that of another genotype.
mericloning A propagation method using shoot tips in culture to proliferate multiple buds, which can then be separated, rooted and planted out.
meristele The branch of a stele supplying the leaf.
meristem Undifferentiated but determined plant tissue, in which the cells are capable of active division and differentiation into specialized tissues such as…
meristem culture A tissue culture containing meristematic dome tissue without adjacent leaf primordia or stem tissue.
meristem tip An explant comprising the meristem (meristematic dome) and usually one pair of leaf primordia.
meristem tip culture Cultures derived from meristem tip explants . Used widely to achieve virus elimination and axillary shoot proliferation, less commonly for callus…
meristemoid A localized group of callus cells, characterized by their accumulation of starch, RNA and protein, and giving rise to adventitious shoots or roots.
merozygote Partial zygote produced by a process of partial genetic exchange, such as transformation in bacteria.
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…
Mesenchymal stem cells Cells from the immature embryonic connective tissue. A number of cell types come from mesenchymal stem cells, including chondrocytes, which produce…
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…
mesh bioreactor See: filter bioreactor.
Mesoderm The middle germ layer that forms in the early animal embryo and gives rise to parts such as bone and connective tissue.
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.
mesophyll Leaf parenchyma tissue found between epidermal layers.
messenger RNA Abbreviation: mRNA.
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…
metabolic cell A cell that is not dividing. See: metabolism
metabolism (meh-TA-boh-lih-zum) The total of all chemical changes that take place in a cell or an organism.
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).
metabolomics The large-scale study of the full complement of secondary metabolites produced by a given species in all its tissues and growth stages.
metacentric chromosome A chromosome in which the centromere is located in the middle and, consequently, the chromosome arms are of about equal length.