Human Genome — page 2 of 5

Human Genome terms

101. Deletion map A description of a specific chromosome that uses defined mutations --specific deleted areas in the genome-- as 'biochemical signposts,' or markers for…
102. Deoxyribonucleic Acid (DNA) (DNA) a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses.
103. Deoxyribonucleotide See: nucleotide.
104. Deoxyribose A type of sugar that is one component of DNA (deoxyribonucleic acid).
105. diabetes mellitus (dye-a-BEE-teez MEL-ih-tus) A group of disorders in which there is a defect in the transfer of glucose (sugar) from the bloodstream into cells, leading to…
106. Diploid The status of having two complete sets of chromosome s, most commonly one set of paternal origin and the other of maternal origin.
107. Directed evolution A laboratory process used on isolated molecules or microbes to cause mutations and identify subsequent adaptations to novel environments.
108. Directed mutagenesis The generation of changes in the nucleotide sequence of a cloned gene by one of several procedures.
109. Directed sequencing Successively sequencing DNA from adjacent stretches of chromosome.
110. Disease-associated genes Alleles carrying particular DNA sequences associated with the presence of disease.
111. DNA (deoxyribonucleic acid) An organic acid and polymer composed of four nitrogenous bases--adenine, thymine, cytosine, and guanine linked via intervening units of phosphate and the…
112. DNA bank A service that stores DNA extracted from blood samples or other human tissue.
113. DNA probe See: probe.
114. DNA repair genes Genes encoding proteins that correct errors in DNA sequencing.
115. DNA replication (… reh-plih-KAY-shun) The process by which a copy of the DNA in a cell is made before the cell divides.
116. DNA sequence The relative order of base pairs, whether in a DNA fragment, gene, chromosome, or an entire genome. See also: base sequence analysis
117. DNA sequencing Procedures for determining the nucleotide sequence of a DNA fragment.
118. Domain A sub-network of servers and computers within a LAN. Domain information is useful when restoring backup tapes, particularly of email.
119. Dominant An allele is said to be dominant if it expresses its phenotype even in the presence of a recessive allele. See Allele, Phenotype, Recessive.
120. Double helix Describes the coiling of the antiparallel strands of the DNA molecule, resembling a spiral staircase in which the paired bases form the steps and the…
121. Draft sequence The sequence generated by the HGP as of June 2000 that, while incomplete, offers a virtual road map to an estimated 95% of all human genes.
122. duplication Multiple occurrence of: 1. A DNA sequence within a defined length of DNA; or 2. A specific segment in the same chromosome or genome.
123. Electrophoresis a technique for the separation of charged molecules by migration on a support medium under the influence of an electrical charge.
124. Electroporation A method for transforrning DNA, especially useful for plant cells, in which high voltage pulses of electricity are used to open pores in cell membranes…
125. Ellis - van Creveld syndrome A rare autosomal recessive disorder that leads to dwarfism, extra fingers, and malformations of the heart, among other abnormalities. See also malformation
126. Embryonic stem (ES) cells Cell lines derived from early embryos that have the potential to differentiate into all types of somatic cells as well as to form germ line cells, and…
127. Endonuclease See Nuclease.
128. enzyme A protein that speeds up chemical reactions in the body.
129. Epistasis Interaction between genes at different loci, e.g. one gene suppresses the effect of another gene that is situated at a different locus.
130. Escherichia coli A commensal bacterium inhabiting the human colon that is widely used in biology, both as a simple model of cell biochemical function and as a host for…
131. Eugenics The application of the principles of genetics to the 'improvement' of humankind. Wholly discredited as a scientific approach since the Nazi period.
132. Eukaryote An organism whose cells possess a nucleus and other membrane-bound vesicles, including all members of the protist, fungi, plant and animal kingdoms; and…
133. Evolutionarily conserved See: conserved sequence
134. Exogenous DNA DNA that has been derived from one organism, and is to be introduced into a cell a different species. Also referred to as foreign DNA or heterologous DNA.
135. Exon A DNA sequence that is ultimately translated into protein. See DNA.
136. Exonuclease See Nuclease.
137. Expressed gene See: gene expression
138. Expressed sequence tag (EST) A short strand of DNA that is a part of a cDNA molecule and can act as identifier of a gene. Used in locating and mapping genes.
139. familial Mediterranean fever An inherited disease whose chief symptoms are recurrent fevers and severe abdominal pain due to inflammation of the abdominal cavity.
140. fibroblasts Irregularly shaped, branching cells distributed throughout vertebrate connective tissue. A cell type which is readily cultured in vitro.
141. Filial generation (F1, F2) Each generation of offspring in a breeding program, designated F1, F2, etc.
142. Fingerprinting See: DNA fingerprinting.
143. Finished DNA Sequence High-quality, low error, gap-free DNA sequence of the human genome. Achieving this ultimate 2003 HGP goal requires additional sequencing to close gaps…
144. Flow cytometry A method of measuring the number of cells in a sample, the percentage of live cells in a sample, and certain characteristics of cells, such as size…
145. Flow karyotyping Use of flow cytometry to analyze and separate chromosomes according to their DNA content.
146. Fluorescence in situ hybridization (FISH) A process which vividly paints chromosomes or portions of chromosomes with fluorescent molecules.
147. Forensics Computer forensics is the scientific examination and analysis of data held on, or retrieved from, computer storage media in such a way that the…
148. Fragile X syndrome After Down syndrome, the second most frequent genetic cause of mental retardation.
149. Fraternal twin Siblings born at the same time as the result of fertilization of two ova by two sperm.
150. Full gene sequence The complete order of bases in a gene. This order determines which protein a gene will produce.
151. Functional genomics The field of research, that aims to determine patterns of gene expression and interaction in the genome, based on the knowledge of extensive or complete…
152. Gamete A haploid sex cell, egg or sperm, that contains a single copy of each chromosome.
153. GC-rich area Many DNA sequences carry long stretches of repeated G and C which often indicate a gene-rich region.
154. Gel electrophoresis See: electrophoresis.
155. Gene The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a…
156. Gene amplification The presence of multiple genes. Amplification is one mechanism through which proto-oncogenes are activated in malignant cells.
157. Gene chip technology Development of cDNA microarrays from a large number of genes. Used to monitor and measure changes in gene expression for each gene represented on the chip.
158. gene expression (JEEN ek-SPREH-shun) The process by which a gene gets turned on in a cell to make RNA and proteins.
159. Gene family Group of closely related genes that make similar products.
160. Gene library See: library.
161. gene mapping See: mapping.
162. Gene pool The totality of all alleles of all genes of all individuals in a particular population.
163. Gene prediction Predictions of possible genes made by a computer program based on how well a stretch of DNA sequence matches known gene sequences
164. Gene product The biochemical material, either RNA or protein, resulting from expression of a gene.
165. Gene testing See: genetic testing, genetic screening
166. gene therapy (jeen THAYR-uh-pee) Treatment that alters a gene. In studies of gene therapy for cancer, researchers are trying to improve the body's natural ability to…
167. gene transfer The insertion of genetic material into a cell.
168. Genetic code The three-letter code that translates nucleic acid sequence into protein sequence.
169. genetic code (ATGC) The instructions in a gene that tell the cell how to make a specific protein. A, T, G, and C are the "letters" of the DNA code; they stand for the…
170. genetic counseling (jeh-NEH-tik KOWN-suh-ling) A communication process between a specially trained health professional and a person concerned about the genetic risk of…
171. Genetic discrimination Prejudice against those who have or are likely to develop an inherited disorder.
172. Genetic engineering The manipulation of an organism's genetic endowment by introducing or eliminating specific genes through modern molecular biology techniques.
173. Genetic engineering technology See: recombinant DNA technology
174. Genetic illness Sickness, physical disability, or other disorder resulting from the inheritance of one or more deleterious alleles.
175. Genetic informatics See: bioinformatics
176. genetic map The linear array of genes on a chromosome, based on recombination frequencies (linkage map) or physical location (physical or chromosomal map).
177. genetic marker Alteration in DNA that may indicate an increased risk of developing a specific disease or disorder.
178. Genetic material See: genome
179. Genetic mosaic An organism in which different cells contain different genetic sequence. This can be the result of a mutation during development or fusion of embryos at…
180. Genetic polymorphism See: polymorphism.
181. Genetic predisposition An inherited increase in the risk of developing a disease. Also called genetic susceptibility.
182. Genetic screening Testing a population group to identify a subset of individuals at high risk for having or transmitting a specific genetic disorder. See also
183. Genetic testing Analyzing DNA to look for a genetic alteration that may indicate an increased risk for developing a specific disease or disorder.
184. Genetics (jeh-NEH-tix) The study of genes and heredity. Heredity is the passing of genetic information and traits (such as eye color and an increased chance of…
185. Genome The complete genetic material of an organism.
186. Genome project Research and technology-development effort aimed at mapping and sequencing the genome of human beings and certain model organisms.
187. Genomic library A library composed of fragments of genomic DNA. (See Library.)
188. Genomic sequence See: DNA
189. Genomics (jeh-NOH-miks) The study of the complete genetic material, including genes and their functions, of an organism.
190. Genotype The structure of DNA that determines the expression of a trait. See Phenotype.
191. Germ cell Reproductive cell. See Somatic cell.
192. germ line A lineage of cells which, during the development of an organism, are set aside as potential gamete-forming tissues.
193. Germ line gene therapy The delivery of a gene or genes to a fertilized egg or an early embryonic cell.
194. Germ line genetic mutation See: mutation
195. guanine (Abbreviation: G). One of the bases found in DNA and RNA. See: guanosine.
196. Guanine (G) A nitrogenous base, one member of the base pair GC (guanine and cytosine) in DNA. See also: base pair, nucleotide
197. Gyandromorph Organisms that have both male and female cells and therefore express both male and female characteristics.
198. Haploid A cell or organism containing one of each of the pairs of homologous chromosomes found in the normal diploid cell.
199. 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
200. Haplotype A specific allelic constitution at a number of loci within a defined linkage block.