Initiation codonThe mRNA sequence AUG, coding for methionine, which initiates translation of mRNA.
initiation factorSoluble protein required for the initiation of translation.
Inner cell massA cluster of cells in the blastocyst from which embryonic stem cell lines can be isolated and grown in culture.
Inner cell mass (ICM)The cluster of cells inside the blastocyst. These cells give rise to the embryo and ultimately the fetus.
inoculateDeliberately introduce, in contrast to contamination. 1. In bacteriology, tissue culture, etc.
inoculation cabinetSmall room or cabinet for inoculation (of tissue or micro-organism cultures) operations, often with a current of sterile air to carry contaminants away…
inoculum(pl.: inocula) 1. A small piece of tissue cut from callus, or an explant from a tissue or organ, or a small amount of cell material from a suspension…
Inorganic compoundHistorically, chemicals that could not be derived from living processes. In modern usage, chemicals that do not contain carbon, although carbonates and a…
inositol(ih-NAH-sih-TOL) A type of sugar that has a different chemical structure than glucose (the chief source of energy for living organisms).
Inositol lipidA membrane-anchored phospholipid that transduces hormonal signals by stimulating the release of any of several chemical messengers. (See Phospholipid.)
insert1. To incorporate a DNA molecule into a cloning vector; also used as a noun to describe such a DNA molecule. 2.
InsertionA type of chromosomal abnormality in which a DNA sequence is inserted into a gene, disrupting the normal structure and function of that gene.
insertion elementGeneric term for DNA sequences found in bacteria capable of genome insertion. Postulated to be responsible for site-specific phage and plasmid integration.
insertion mutationChanges in the base sequence of a DNA molecule resulting from the random integration of DNA from another source. See: mutation.
Insertion mutationsChanges in the base sequence of a DNA molecule resulting from the random integration of DNA from another source. See DNA, Mutation.
InstabilityA lack of consistent phenotype, usually as a result of uncontrolled genetic changes.
insulin(IN-su-lin) A hormone made by the islet cells of the pancreas. Insulin controls the amount of sugar in the blood by moving it into the cells, where it can…
Insulin-promoting factor 1A transcription factor expressed in the pancreas and necessary for the production of insulin.
integrating vectorA vector that is designed to integrate cloned DNA into the host's chromosomal DNA.
IntegrationThe recombination process which inserts a small DNA molecule (usually by homologous recombination) into a larger one.
integration-excision region(Abbreviation: I/E). The portion of bacteriophage lambda (ë) DNA that enables ë-DNA to be inserted into a specific site in the E.
Integrative CareAt CTCA, a patient meets with both an oncologist specializing in conventional therapies as well as practitioners of complementary and alternative…
integumentOne of the layers that enclosed the ovule, and is the precursor of the seed coat.
intellectual property rights(Abbreviation: IPR). The legal framework, which includes patenting and plant variety protection, by which inventors control the commercial application of…
intensifying screenA plastic sheet impregnated with a rare-earth compound, such as calcium tungstate, which reacts to radiation by emitting light.
inter-simple sequence repeat(Abbreviation: ISSR). A PCR -based molecular marker assay of genomic sequence lying between adjacent microsatellites .
intercalary1. Meristematic tissue or growth not restricted to the apex of an organ, i.e. growth at nodes. 2. Referring to internal segments of a chromosomes (i.e.
intercalary growthA pattern of stem elongation typical of grasses. Elongation proceeds from the lower internodes to the upper internodes through the differentiation of…
intercalating agentA chemical capable of inserting between adjacent base pairs in a double-stranded nucleic acid. A prominent example is ethidium bromide.
intercellular spaceThe pore space between cells, especially typical of leaf tissues.
interferencea proceeding, conducted before the Board of Patent Appeals and Interferences (Board), to determine priority of invention between a pending application and…
interferon(in-ter-FEER-on) A biological response modifier (a substance that can improve the body's natural response to infections and other diseases).
intergeneric crossA hybrid made between parents belonging to two different genera.
Intergenic regionsDNA sequences located between genes that comprise a large percentage of the human genome with no known function.
intergenic spacer(Abbreviation: IGS). Non-coding DNA separating tandemly arranged copies of a repeated gene sequence (typically ribosomal DNA ).
interleukin(in-ter-LOO-kin) One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body.
internodeThe region of a stem between two successive nodes.
InterphaseThe stage in the cell cycle when the cell is not dividing and during part of which DNA replication occurs; it follows telophase of one mitotic division…
intracytoplasmic sperm injection(Abbreviation: ICSI). The micro-injection of a single sperm into the cytoplasm of a mature oocyte.
intragenericWithin a genus, such as an intrageneric cross, or intrageneric variation.
intrageneric crossA hybrid made between parents belonging to two species in the same genus. See: intraspecific cross, interspecific cross.
intragenic complementationOccurs when wild type phenotype is restored in an F1 individual made by crossing two independent mutants, carrying different heteroalleles.
intraspecificWithin a species, such as an intraspecific cross, or intraspecific variation.
intraspecific crossA hybrid made between parents belonging to the same species. See: intrageneric cross, interspecific cross.
Intravenous(IN-truh-VEE-nus) Into or within a vein. Intravenous usually refers to a way of giving a drug or other substance through a needle or tube inserted into a…
IntrogressionBackcrossing of hybrids of two plant populations to introduce new genes into a wild population.
IntronA noncoding DNA sequence within a gene that is initially transcribed into messenger RNA but is later snipped out.
InvasivenessAbility of a plant to spread beyond its introduction site and become established in new locations where it may provide a deliterious effect on organisms…
InversionA chromosome re-arrangement, which involves the re-orientation of a segment so that the order of a linear array of genes within it is reversed.
inverted repeatTwo sequences of nucleotides occurring in one strand, where, relative to the first sequence, the second has complementary bases but in the inverted order.
IonAn atom or molecule that has lost or gained one or more electrons and has become electrically charged as a result.
ion channelA protein integral to a cell membrane, through which selective ion transport occurs.
IPTGAbbreviation for isopropyl-3-D-thiogalactopyranoside. A synthetic inducer of beta-galactosidase activity in many bacteria.
IrradiateApplication of radiation from a source (heat, light, Xrays) to a structure or organism.
irradiation(ih-RAY-dee-AY-shun) The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors.
IS elementAbbreviation for insertion sequence element. A short (800-1400 nucleotide pairs) found in bacteria that is capable of transposing to a new genomic…
iso-electric focusing gel(Abbreviation: IEF gel). A variant of gel electrophoresis, in which macromolecules (usually protein s) are separated on the basis of differing…
isoalleleMultiple similar copies of a gene, usually located at independent positions in the genome, which encode similar gene products and produce the same, or a…
isochromosomeA chromosome produced following an error in meiosis, in which the two arms are mirror images of each other.
isodiametricCommonly used to describe cells with equal diameters.
isoform1. A tissue-specific form of a protein. 2. Synonym of isoenzyme.
isogamyFusion of gametes of similar size and structure.
isogenicA group of individuals that possesses the same genotype, irrespective of their being homozygous or heterozygous.
isogenic stockStrains of organisms that are genetically nearly identical, except with respect to identified genes.
isolating mechanismThe properties of an organism that prevent interbreeding (and therefore exchange of genetic material) between members of different species that inhabit…
isolation mediumAn optimum plant tissue culture medium suitable for explant survival, growth and development.
isomerOne of two or more compounds that have the same chemical formula but different arrangements of the atoms within the molecules and that may have different…
isomeraseAny of a class of enzymes that catalyse the re-arrangement of the atoms within a molecule, thereby converting one isomer into another.
isotonicSolutions with the same osmotic potential, as a result of being of the same molar concentration.
isotope(I-soh-tope) A form of a chemical element in which the atoms have the same number of protons (part of the nucleus of an atom) but with a different number…
isozymeA genetic variant of an enzyme. Isozymes for a given enzyme share the same function, but may differ in level of activity, as a result of minor differences…
ISSRAbbreviation for inter-simple sequence repeat.