Food Biotechnology terms starting with H

140 terms

H Prefix used to designate the human form of an enzyme. For example, hGH is human growth hormone.
habituation The phenomenon whereby, after a number of sub-cultures, cells can grow without the addition to the tissue culture medium of previously obligatory factors.
HAC Abbreviation for human artificial chromosome.
haemoglobin Protein containing iron, located in erythrocytes of vertebrates; important for the transportation of oxygen to the cells of the body.
haemolymph The mixture of blood and other fluids in the body cavity of an invertebrate.
haemophilia A sex-linked hereditary bleeding disorder in which it takes a long time for the blood to clot and abnormal bleeding occurs.
hairpin loop A region in one strand of a polynucleotide which, due to an inverted repeat in the sequence, may under appropriate conditions fold back on itself and form…
hairy root culture A culture consisting of highly branched roots of a plant. A plant tissue is treated with the bacterium Agrobacterium rhizogenes containing the Ri plasmid…
hairy root disease A disease of broad-leaved plants, where a proliferation of root-like tissue is formed from the stem.
halophyte A plant species adapted to soils containing a concentration of salt that is toxic to most plant species. See: salt tolerance.
hanging droplet technique See: microdroplet array.
Haploid A cell or organism containing one of each of the pairs of homologous chromosomes found in the normal diploid cell.
Haploid cell A cell containing only one set, or half the usual (diploid) number, of chromosomes.
Haplotype A specific allelic constitution at a number of loci within a defined linkage block.
haplozygous See: hemizygous.
hapten A small molecule, which by itself is not an antigen, but which as a part of a larger structure when linked to a carrier protein, can serve as an antigenic…
haptoglobin A serum protein that interacts with haemoglobin during recycling of the iron molecule of haemoglobin. Synonym: alpha globulin.
hardening off Adapting glasshouse or controlled environment grown plants to outdoor conditions by reducing availability of water, lowering the temperature, increasing…
Hardy-Weinberg equilibrium The frequencies of genotypes at a locus resulting from random mating at that locus; for two alleles, A1 and A2, with respective frequencies in a…
Harvesting The process of retrieving or collecting electronic data from storage media or devices; an EDiscovery vendor harvests electronic data from computer hard…
heat shock protein (... PROH-teen) One of a group of proteins that help protect cells from stresses such as heat, cold, and low amounts of oxygen or glucose (sugar).
heat therapy See: thermotherapy.
helix A structure with a spiral shape. The normal state of double-stranded DNA is in the form of a double helix.
helminth A class of parasitic worms, especially those which are internal parasites of man and animals.
helper cell T cells that assist in stimulating B and T lymphocyte s to develop into antibody-producing plasma cells and killer T cells, respectively.
helper plasmid A plasmid that provides a function or functions to another plasmid in the same cell.
helper T cell A type of white blood cell that helps stimulate immune system reactions. Helper T cells help activate cytotoxic T cells and macrophages by secreting…
helper T lymphocyte See: helper cell.
helper virus A virus that provides a function or functions to another virus in the same cell.
hemicellulase An enzyme that catalyses the degradation of hemicellulose.
hemicellulose Any cellulose-like carbohydrate, but excluding cellulose itself. Together with pectin and lignin, hemicelluloses form the cell wall matrix.
Hemizygous The condition in which genes are present only once in the genotype and not in pairs.
hemoglobin (HEE-moh-GLOH-bin) The substance inside red blood cells that binds to oxygen in the lungs and carries it to the tissues.
hemolymph See: haemolymph.
hemophilia Group of hereditary disorders in which affected individuals fail to make enough of certain proteins needed to form blood clots.
HEPA filter Abbreviation for high efficiency particulate air filter. A filter capable of excluding particles larger than 0.3ìm.
Herbicide A chemical that kills plants.
herbicide resistance The ability of a plant to remain unaffected by the application of a herbicide.
Herbicide-tolerant crop Crop plants that have been developed to survive application(s) of one or more commercially available herbicides by the incorporation of certain gene(s)…
heredity Resemblance among individuals related by descent; transmission of traits from parents to offspring.
heritability The degree to which a given trait is controlled by inheritance, as opposed to being controlled by non-genetic factors.
hermaphrodite 1. An animal that has both male and female reproductive organs, or a mixture of male and female attributes. 2.
heteroallele A gene having mutations at two or more different sites.
Heterochromatin Dark-stained regions of chromosomes thought to be for the most part genetically inactive.
Heteroduplex A double-stranded DNA molecule or DNA-RNA hybrid, where each strand is of a different origin.
heteroduplex analysis The use of the electrophoretic mobility of to estimate the degree of non-homology between the sequences of the two strands.
heterogametic Producing unlike gametes with regard to the sex chromosomes. In mammals, the XY male is heterogametic, and the XX female is homogametic.
Heterogeneity See: genetic heterogeneity.
heterogeneous nuclear RNA (Abbreviation: hnRNA ). Large RNA molecules, which are found in the nucleus of a eukaryotic cell and the precursors of mRNA and other RNA molecules.
Heterogeneous nuclear RNA (hnRNA) The name originally given to large RNA molecules found in the nucleus, which are now known to be unedited mRNA transcripts, or pre-mRNAs. (See RNA.)
heterokaryon A cell with two or more different nuclei as a result of cell fusion. See: synkaryon.
Heterologous From a different source.
heterologous probe A DNA probe that is derived from one species and used to screen for a similar DNA sequence from another species.
heterologous protein See: recombinant protein.
heteroplasmy A condition in which two genetically different organelles are present in the same cell. The equivalent to heterozygous in the context of nuclear genes.
heteroploid Cells with nuclei containing chromosome numbers other than diploid.
heteropyknosis The property of certain chromosomes, or of their parts, to remain more dense during the cell cycle and to stain more intensely than other chromosomes or…
heterosis See: hybrid vigour.
heterotroph Organism non capable of self-nourishment utilizing carbon dioxide or carbonates as the sole source of carbon and obtaining energy from radiant energy or…
heterotrophic (adj.) See: heterotroph.
Heterozygote An individual with non-identical alleles for a particular gene or genes. The condition is termed "heterozygous". Opposite: homozygote.
heterozygous (adj.) See: heterozygote.
Hfr High-frequency recombination strain of Escherichia coli; in these strains, the F factor (plasmid) is integrated into the bacterial chromosome.
HGH See Human growth hormone.
high efficiency particulate air filter See: HEPA filter.
high throughput screening Automated systems designed to process large numbers of assays, especially in the context of genotyping.
histocompatibility The degree to which tissue from one organism is tolerated by the immune system of another organism.
histocompatibility complex See: major histocompatibility complex.
histoglobulin The peptides present on the surface of nucleate cells, responsible for the differences between genetically non-identical individuals that cause rejection…
histology (his-TAH-loh-jee) The study of tissues and cells under a microscope.
histone A type of protein found in chromosomes. Histones bind to DNA, help give chromosomes their shape, and help control the activity of genes.
HLA One of a group of proteins found on the surface of white blood cells and other cells that play an important part in the body's immune response to foreign…
hnRNA See Heterogeneous nuclear RNA.
Hogness box Synonym for TATA box.
hollow fibre A tube of porous material, with an internal diameter of a fraction of a millimetre, making its ratio of surface area to internal volume very large.
holoenzyme See: apoenzyme.
holometabolous An insect that undergoes complete metamorphosis to the adult from a morphologically distinct larval stage.
Homeobox A highly conserved 180 bp DNA sequence that controls body part-, organ- or tissue-specific gene expression, most particularly involved in segmentation in…
homeodomain See: homeobox.
homeotic genes Genes that act in concert to determine fundamental patterns of development.
homeotic mutation A mutation that causes a body part to develop in an inappropriate position in an organism, such as the mutation in Drosophila melanogaster that causes…
homoallele One of a number of otherwise identical alleles which differ at the same site in their sequence.
homodimer A protein comprising two identical polypeptide chains, or a dimer of identical residues.
homoduplex DNA A double-stranded fully complementary DNA molecule.
homoeologous Referring to chromosome s which are descended from a common progenitor, but which have evolved to be no longer fully homologous.
homogametic Producing similar gametes with regard to the sex chromosomes . In mammals, the female is homogametic (XX), and the male is heterogametic (XY).
homogenotization An allele replacement technique, in which a bacterial cell is transformed with a plasmid containing an altered copy of the target sequence, and a double…
homokaryon A cell with two or more identical nuclei as a result of fusion. Opposite: heterokaryon.
Homolog In diploid organisms, one member of a pair of matching chromosomes.
Homologous 1. General definition: from the same source, or having the same evolutionary function or structure. 2.
Homologous chromosomes Chromosomes that have the same linear arrangement of genes--a pair of matching chromosomes in a diploid organism. See Chromosomes.
Homologous recombination The exchange of DNA fragments between two DNA molecules or chromatids of paired chromosomes (during crossing over) at the site of identical nucleotide…
Homology 1. The degree of identity between individuals, or characters. 2. The degree of identity of sequence (nucleotide or amino acid) between a number of DNA or…
homomultimer A protein consisting of a number of identical subunits.
homoplasmy The condition in which all copies of an organelle in a cell are genetically identical. Opposite: heteroplasmy.
homopolymer A polymer (nucleic acid, polypeptide, etc.) which contains only one kind of residue (e.g. the polynucleotide GGGGGGGGG...).
homopolymeric tailing See: tailing.
Homozygote An organism whose genotype is characterized by two identical alleles of a gene. See Allele, Genotype.
homozygous (adj.) See: homozygote.
Horizontal gene transfer Transmission of DNA between species, involving close contact between the donor's DNA and the recipient, uptake of DNA by the recipient, and stable…