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Arctic Regions definition: The Arctic Ocean and the lands in it and adjacent to it. It includes Point Barrow, Alaska, most of the Franklin District in Canada, two thirds of Greenland, Svalbard, Franz Josef Land, Lapland, Novaya Zemlya, and Northern Siberia. (Webster's New Geographical Dictionary, 1988, p66)
AT Rich Sequence definition: A nucleic acid sequence that contains an above average number of ADENINE and THYMINE bases.
back definition: posterior part of the trunk from the neck to the pelvis.
Body Regions definition: Anatomical areas of the body.
body region definition: a general term for grouping regions of the body; preference is to use NTs.
Body Region definition: Named areas of the body.
Branchial Region definition: A region, of SOMITE development period, that contains a number of paired arches, each with a mesodermal core lined by ectoderm and endoderm on the two sides. In lower aquatic vertebrates, branchial arches develop into GILLS. In higher vertebrates, the arches forms outpouchings and develop into structures of the head and neck. Separating the arches are the branchial clefts or grooves.
Desert Climate definition: A type of climate characterized by insufficient moisture to support appreciable plant life. It is a climate of extreme aridity, usually of extreme heat, and of negligible rainfall. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
arid climate definition: climate lacking moisture, especially having insufficient rainfall to support trees or woody plants.
Immunoglobulin Constant Region definition: The portion of an antibody that is invariant within a class of immunoglobulins. It is comprised of the carboxyl terminal half of both light chains and at least three quarters of each heavy chain starting from the carboxyl terminus and excludes the variable regions of the heavy and light chains.
Immunoglobulin Constant Regions definition: The domains of the immunoglobulin molecules that are invariable in their amino acid sequence within any class or subclass of immunoglobulin. They confer biological as well as structural functions to immunoglobulins. One each on both the light chains and the heavy chains comprises the C-terminus half of the IMMUNOGLOBULIN FAB FRAGMENT and two or three of them make up the rest of the heavy chains (all of the IMMUNOGLOBULIN FC FRAGMENT)
Complementarity Determining Regions definition: Three regions (CDR1; CDR2 and CDR3) of amino acid sequence in the IMMUNOGLOBULIN VARIABLE REGION that are highly divergent. Together the CDRs from the light and heavy immunoglobulin chains form a surface that is complementary to the antigen. These regions are also present in other members of the immunoglobulin superfamily, for example, T-cell receptors (RECEPTORS, ANTIGEN, T-CELL).
Immunoglobulin Hypervariable Region definition: Within the variable domain of an antibody molecule are three regions called hypervariable regions, areas of high sequence diversity. These regions form the surfaces that are responsible for antigen binding interactions. Also known as complementarity determining region or hypervariable loop.
Back of abdomen definition: Subdivision of abdomen which is demarcated from the front of the abdomen by the posterior surface of the anterior layer of the thoracolumbar fascia and the anterior surface of the lumbar vertebral column; together with the front of the abdomen, it constitutes the abdomen. Examples: There is only one back of abdomen.
Back of abdomen definition: Subdivision of abdomen which is demarcated from the front of the abdomen by the posterior surface of the anterior layer of the thoracolumbar fascia and the anterior surface of the lumbar vertebral column; together with the front of the abdomen, it constitutes the abdomen. Examples: There is only one back of abdomen.
lumbosacral region definition: region of the back between thorax and pelvis.
genetic operator element definition: regulatory elements of an operon to which activators or repressors bind thereby effecting the transcription of genes in the operon.
Operator Regions, Genetic definition: The regulatory elements of an OPERON to which activators or repressors bind thereby effecting the transcription of GENES in the operon.
genetic promoter element definition: DNA sequences which are recognized and bound by a DNA-dependent RNA polymerase during the initiation of transcription; highly conserved sequences within the promoter include the TATA BOX in eukaryotes.
Promoter Regions, Genetic definition: DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.
Regulatory Sequences, Nucleic Acid definition: Nucleic acid sequences involved in regulating the expression of genes.
genetic regulatory element definition: binding sites on DNA for proteins that control genetic events; compare with STRUCTURAL GENE and REGULATORY GENE.
Regulatory Element definition: Any DNA sequence involved in the regulation of genetic processes such as transcription and replication.
genetic terminator element definition: DNA sequences which signal the termination of transcription.
Terminator Regions, Genetic definition: DNA sequences recognized as signals to end GENETIC TRANSCRIPTION.
Immunodominant Epitopes definition: Subunits of the antigenic determinant that are most easily recognized by the immune system and thus most influence the specificity of the induced antibody.
Open Reading Frames definition: A sequence of successive nucleotide triplets that are read as CODONS specifying AMINO ACIDS and begin with an INITIATOR CODON and end with a stop codon (CODON, TERMINATOR).
open reading frame definition: sequences of structural genes devoid of termination codons and therefore continuously "readable" by RNA polymerase.
Coding Region definition: The sequences on a gene or messenger RNA that are translated into protein.
Open Reading Frame definition: A sequence of nucleotides in that contains no termination codons and so can potentially translate as a polypeptide chain.
Repetitive Sequence definition: Nucleotide sequences present in multiple copies in the genome. There are several types of repeated sequences. Interspersed (or dispersed) DNA repeats (Interspersed Repetitive Sequences) are copies of transposable elements interspersed throughout the genome. Flanking (or terminal) repeats (Terminal Repeat Sequences) are sequences that are repeated on both ends of a sequence, for example, the long terminal repeats (LTRs) on retroviruses. Direct terminal repeats are in the same direction and inverted terminal repeats are opposite to each other in direction. Tandem repeats (Tandem Repeat Sequences) are repeated copies which lie adjacent to each other. These can also be direct or inverted. The ribosomal RNA and transfer RNA genes belong to the class of middle repetitive DNA.
Bay-Region, Polycyclic Aromatic Hydrocarbon definition: A concave exterior region on some POLYCYCLIC AROMATIC HYDROCARBONS that have three phenyl rings in a non-linear arrangement.
Minisatellite Repeats definition: Tandem arrays of moderately repetitive (5-50 repeats) short (10-60 bases) DNA sequences found dispersed throughout the genome and clustered near telomeres. Their degree of repetition is two to several hundred at each locus. Loci number in the thousands but each locus shows a distinctive repeat unit. Minisatellite repeats are often called variable number of tandem repeats.
Minisatellite Repeat definition: Tandem arrays of moderately repetitive (5-50 repeats) short (10-60 bases) DNA sequences found dispersed throughout the genome and clustered near telomeres. Their degree of repetition is two to several hundred at each locus. Loci number in the thousands but each locus shows a distinctive repeat unit.
Replication Origin definition: A unique DNA sequence of a replicon at which DNA REPLICATION is initiated and proceeds bidirectionally or unidirectionally. It contains the sites where the first separation of the complementary strands occurs, a primer RNA is synthesized, and the switch from primer RNA to DNA synthesis takes place. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
Origin of Replication definition: A DNA sequence necessary and sufficient for initiation of DNA replication.
Antarctic Regions definition: The continent lying around the South Pole and the southern waters of the Atlantic, Pacific, and Indian Oceans. It includes the Falkland Islands Dependencies. (From Webster's New Geographical Dictionary, 1988, p55)
ATA definition: The continent lying mostly south of the Antarctic Circle. (NCI)
Antarctica definition: The continent lying mostly south of the Antarctic Circle.
Locus Control Region definition: A regulatory region first identified in the human beta-globin locus but subsequently found in other loci. The region is believed to regulate GENETIC TRANSCRIPTION by opening and remodeling CHROMATIN structure. It may also have enhancer activity.
5' Untranslated Regions definition: The sequence at the 5' end of the messenger RNA that does not code for product. This sequence contains the ribosome binding site and other transcription and translation regulating sequences.
5' Untranslated Region definition: Sequences on the 5' end of messenger RNAs that are not translated into protein. 5'UTR extends from the transcription start site to just before the ATG translation initiation codon. This region contains the ribosome binding site and other transcription and translation regulating sequences.
Catalytic Domain definition: The region of an enzyme that interacts with its substrate to cause the enzymatic reaction.
3' Untranslated Regions definition: The sequence at the 3' end of messenger RNA that does not code for product. This region contains transcription and translation regulating sequences.
3' Untranslated Region definition: Sequences on the 3' end of messenger RNAs that are not translated into protein. The 3'UTR is involved in many post-transcriptional regulatory pathways, including regulating translation efficiency, mRNA stability, and polyadenylation signals.
Untranslated Regions definition: The parts of the messenger RNA sequence that do not code for product, i.e. the 5' UNTRANSLATED REGIONS and 3' UNTRANSLATED REGIONS.
Untranslated Region definition: A region of a messenger RNA that is not translated into protein.
5' Flanking Region definition: The region of DNA which borders the 5' end of a transcription unit and where a variety of regulatory sequences are located.
3' Flanking Region definition: The region of DNA which borders the 3' end of a transcription unit and where a variety of regulatory sequences are located.