biotic factorOther living organisms that are a component of an organism's environment, and form the biotic environment, affecting the organism in many ways.
Biotic stressLiving organisms which can harm plants , such as viruses, fungi, and bacteria, and harmful insects. See Abiotic stress.
biotinA vitamin of the B complex, it acts as a co-enzyme for various enzymes that catalyse the incorporation of carbon dioxide into various compounds, and is…
biotin labellingThe attachment of biotin to another molecule, especially DNA.
biotinylated-DNAA DNA molecule labelled with biotin by incorporation of a biotinylated nucleotide (usually uracil ) into a DNA molecule.
biotoxinA naturally produced compound which shows pronounced biological activity, toxic to some or many organisms.
biotransformationThe conversion of one chemical or material into another using a biological catalyst : a near synonym is biocatalysis, and hence the catalyst used is…
Birth defectA structural, functional, or metabolic abnormality present at birth that results in physical or mental disability or is fatal.
bivalentTwo paired homologous chromosomes (one of maternal origin; the other of paternal origin) at prophase to anaphase of the first meiotic division.
blast cellA large, rapidly dividing cell that develops from a B cell in response to an antigenic stimulus.
BlastocoelThe fluid-filled cavity inside the blastocyst of the developing embryo.
BlastocystA mammalian embryo (fertilized ovum) in the early stages of development, approximately up to the time of implantation.
Blastocyst stageAn early stage in the development of embryos, when (in mammals) the embryo is a spherical body comprising an inner cell mass that will become the fetus…
blastomereAny one of the cells formed from the first few cleavages in animal embryology. The embryo usually divides into two, then four, then eight blastomeres, and…
BlastulaIn animals, an early embryo form that follows the morula stage; typically, a single-layered sheet (blastoderm) or ball of cells (blastocyst ).
bleeding1. Collection of blood from immunized animals. 2. Used to describe the occasional purplish-black colouration of media due to phenolic products given off…
Blood Cell SeparatorA machine, used in apheresis, which distinguishes the small fraction of stem cells in the blood from all other blood cells, so that the stem cells may be…
blotAs a verb, to transfer DNA, RNA or protein to an immobilizing matrix. As a noun, the immobilizing matrix carrying DNA, RNA or protein.
blunt endThe end of a double-stranded DNA molecule in which neither strand extends beyond the other. Synonym: flush end.
blunt-end cutTo cut a double-stranded DNA with a restriction endonuclease which generates blunt ends . Synonym: flush-end cut.
blunt-end ligationThe joining of two blunt-ended double-stranded DNA molecules.
Bone Marrow Aspiration(bone MAYR-oh as-pih-RAY-shun) The removal of a small sample of bone marrow (usually from the hip) through a needle for examination under a microscope.
Bone Marrow Biopsy(bone MAYR-oh BY-op-see) The removal of a sample of tissue from the bone marrow with a needle for examination under a microscope.
Bone marrow stem cell (BMSC)One of at least two types of multipotient stem cells: hematopoietic stem cell and mesenchymal stem cell.
Bone marrow stromal cellAlso known as mesenchymal stem cells, bone marrow stromal cells are a mixed population of cells derived from the non-blood forming fraction of bone marrow.
Bone marrow stromal cellsA mixed population of stem cells found in bone marrow that does not give rise to blood cells but instead generates bone, cartilage, fat, and fibrous…
bone marrow transplantation(bone MAYR-oh tranz-plan-TAY-shun) A procedure to replace bone marrow that has been destroyed by treatment with high doses of anticancer drugs or…
Bone marrow transplantation (BMTx)Trans-planta-tion of bone marrow from one individual to another. Autologous BMTx is a process in which a patient's healthy bone marrow is withdrawn and…
Bone morphogenetic proteins (BMPs)Proteins thatare involved in the formation of embryonic bone. BMPs operate at several stages in this formation of bone, beginning with the early stages of…
boring platformSterile bottom half of a Petri dish used for preparing explants with a cork borer.
bound waterCellular water not released into the intercellular space upon freezing and thawing. Opposite: free water.
bovine somatotrophin(Abbreviation: BST) A natural protein in cattle. It has been cloned, using recombinant DNA technology, expressed in large amounts and marketed as an…
BRCA1/BRCA2The first breast cancer genes to be identified. Mutated forms of these genes are believed to be responsible for about half the cases of inherited breast…
breed1.a sub-specific group of domestic livestock with definable and identifiable external characteristics that enable it to be separated by visual appraisal…
breed at riskAn animal breed that is in danger of becoming extinct because its population has fallen below a critical number.
breedingThe process of sexual reproduction and production of offspring.
breeding valueA quantitative genetics term, describing that part of the deviation of an individual phenotype from the population mean that is due to the additive…
brewer's yeastStrains of the yeast Saccharomyces cerevisiae that are used for the production of beer.
bridgeA filter paper or other substrate used as a wick and support structure for a plant tissue in culture when a liquid medium is used.
broad-host-range plasmidA plasmid that can replicate in a number of different bacterial species.
broad-sense heritabilityThe proportion of the total phenotypic variation which results from genetic variation or interaction between the genotype and the environment.
broodstockThe group of males and females from which fish are bred.
browningDiscolouration of freshly cut surfaces of plant tissue due to phenolic oxidation.
Bt cornA corn plant that has been developed though biotechnology so that the plant tissues express a protein derived from a bacterium, Bacillus thuringiensis…
bubble column fermenterA bioreactor in which the cells or micro-organisms are kept suspended in a tall cylinder by rising air, which is introduced at the base of the vessel.
budA region of meristematic tissue with the potential for developing into leaves, shoots, flowers or combinations of these; generally protected by modified…
bud sportA somatic mutation arising in a bud, generating a genetically different shoot. Includes changes due to gene mutation, chromosomal mutation or polyploidy.
budding1. A method of asexual reproduction in which a new individual is derived from an outgrowth (bud) that becomes detached from the body of the parent. 2.
bulked segregant analysisA method to obtain markers linked to a target trait, in which DNA samples, prepared from a number of individuals of each of two contrasting phenotypes…
buoyant densityThe intrinsic density which a molecule, virus or sub-cellular particle has when suspended in an aqueous solution of a salt, such as CsCl, or a sugar, such…
callipygeAn inherited trait in livestock (e.g. sheep) that results in thicker, meatier hind-quarters, and hence a higher meat yield per animal.
callus(pl.: calli) A protective tissue, consisting of parenchyma cells, that develops over a cut or damaged plant surface. 2.
callus cultureA technique of plant tissue culture, usually on solidified medium and initiated by inoculation of small explants .
cambial zoneRegion in stems and roots consisting of the cambium and its recent derivatives.
cambium(pl.: cambia) A one or two cells thick layer of plant meristematic tissue, between the xylem and phloem tissues, which gives rise to secondary tissues…
cAMPAbbreviation for cyclic adenosine monophosphate.
Cancer(KAN-ser) A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread to other parts of the…
candidate geneA gene whose deduced function (on the basis of DNA sequence) suggests that it may be involved in the genetic control of an aspect of phenotype.
candidate-gene strategyAn experimental approach in which knowledge of the biochemistry and/or physiology of a trait is used to identify candidate gene s.
canolaA specific subgroup of oilseed rape cultivars; canola oil is the highly mono-unsaturated fatty acid and low in erucic acid product produced in the seed of…
CapA cap is a ceiling, or the highest level to which something can go. For example, an interest rate cap limits the amount by which an interest rate can be…
cap siteThe site on a DNA template where transcription begins. It corresponds to the nucleotide at the 5' end of the RNA transcript which accepts the G cap.
capacitationThe final stage, inside the female genital tract, in the maturation process of a spermatozoon, as it penetrates the ovum.
Capillary arrayGel-filled silica capillaries used to separate fragments for DNA sequencing. The small diameter of the capillaries permit the application of higher…
capillary electrophoresisA form of electrophoresis used widely in current large-scale DNA sequencing facilities, where the sample is passed through a long, very-narrow-bore tube…
capsule(KAP-sool) In medicine, a sac of tissue and blood vessels that surrounds an organ, joint, or tumor.
carbohydrateA sugar molecule. Carbohydrates can be small and simple (for example, glucose) or they can be large and complex (for example, polysaccharides such as…
carboxypeptidaseA class of enzymes which catalyse the cleavage of peptide bonds, requiring a free carboxyl group in the substrate.
carcinogen(kar-SIN-o-jin) Any substance that causes cancer.
carcinoma(KAR-sih-NOH-muh) Cancer that begins in the skin or in tissues that line or cover internal organs.
caroteneA reddish-orange plastid pigment involved in photosynthesis. A carotenoid and precursor of vitamin A.
carotenoidA substance found in yellow and orange fruits and vegetables and in dark green, leafy vegetables. Carotenoids may reduce the risk of developing cancer.
carpelFemale reproductive organ of flowering plants, consisting of stigma, style and ovary.
carrierA heterozygous individual bearing a recessive mutant allele for a defective condition that is "masked" by the presence of the dominant normal allele; the…
carrier DNA DNAof undefined sequence which is added to the transforming (plasmid ) DNA used in physical DNA -transfer procedures.