Biotechnology and Genetics terms starting with H

178 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 drop method A technique used to culture embryonic stem cells so that they develop into embryoid bodies.
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.
Haploid human cell A cell such as an egg or sperm that contains only twenty-three chromosomes.
haploinsufficiency A situation in which the protein produced by a single copy of an otherwise normal gene is not sufficient to assure normal function. See also gene, protein
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…
hCNS Human central nervous system stem cell.
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.
Hematological Oncologist A medical doctor who specializes in diagnosing and treating malignancies, or cancers, of the blood and blood- forming tissues.
Hematologist (HEE-muh-TAH-loh-jist) A doctor who specializes in treating blood disorders.
Hematopoiesis (hee-MA-toh-poy-EE-sus) The formation of new blood cells.
Hematopoietic cell transplantation The transplantation of hematopoietic stem cells with blood-forming potential. Hematopoietic stem cells provide rapid and sustained reconstitution of blood…
Hematopoietic stem cell An unspecialized precursor cell that will develop into a mature blood cell. See also cell
Hematopoietic stem cell (HSC) A stem cell from which all red and white blood cells evolve.
Hematopoietic stem cells The precursors of mature blood cells that are defined by their ability to replace the bone marrow system following its obliteration (for example, by…
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.
Hepatic (hih-PA-tik) Refers to the liver.
Hepatocyte (HEP-a-toe-site) A liver cell.
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)…
Hereditary cancer Cancer that occurs due to the inheritance of an altered gene within a family. See also: sporadic cancer
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.
hES cell Human embryonic stem cell; a type of pluripotent stem cell.
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.
Heterozygosity The presence of different alleles at one or more loci on homologous chromosomes.
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.
High-throughput sequencing A fast method of determining the order of bases in DNA. See also: sequencing
Highly conserved sequence A DNA sequence that is very similar in several different kinds of organisms. Scientists regard these cross species similarities as evidence that a…
Hirschsprung's disease A congenital disorder in which part of the colon lacks nerve cells and therefore is unable to relax.
histocompatibility The degree to which tissue from one organism is tolerated by the immune system of another organism.
histocompatibility complex See: major histocompatibility complex.
Histocompatible A tissue or organ from a donor (the person giving the organ or tissue) that will not be rejected by the recipient (the patient in whom the tissue or organ…
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.
Hoechst dye A dye used to identify hematopoietic stem cells (HSCs).
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.
holoprosencephaly A birth defect where the forebrain does not separate properly into two halves during early fetal life.
Homeobox A highly conserved 180 bp DNA sequence that controls body part-, organ- or tissue-specific gene expression, most particularly involved in segmentation in…