genetic code(redirected from Standard genetic code)
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1. pertaining to reproduction or to birth or origin.
genetic code the arrangement of nucleotides in the polynucleotide chain of a chromosome; it governs the transmission of genetic information to proteins, i.e., determines the sequence of amino acids in the polypeptide chain making up each protein synthesized by the cell. Genetic information is coded in DNA by means of four bases: two purines (adenine and guanine) and two pyrimidines (thymine and cystosine). Each adjacent sequence of three bases (a codon) determines the insertion of a specific amino acid. In RNA, uracil replaces thymine.
1. the location of mutations along the length of a chromosome, as determined by recombination experiments. The unit of length is the centimorgan (cM), one crossover per meiosis.
2. the sequence of base pairs along the DNA of a chromosome, a technique being applied to humans.
genetic marker a gene having alleles that are all expressed in the phenotype, that is, they are codominant, and which can be used to study inheritance. The various blood group systems and serum or red blood cell proteins easily detected by electrophoresis or immunodiffusion are commonly used markers.
the genetic information carried by the specific DNA molecules of the chromosomes; specifically, the system whereby particular combinations of three consecutive nucleotides in a DNA molecule control the insertion of one particular amino acid in equivalent places in a protein molecule. The genetic code is almost universal throughout the prokaryotic, plant, and animal kingdoms. There are two known exceptions: In ciliated protozoans, the triplets AGA and AGG are read as termination signals instead of as l-arginine. This is also true of the human mitochondrial code, which, in addition, uses AUA as a code for l-methionine (instead of l-isoleucine) and UGA for l-tryptophan (instead of a termination signal).
1. The set of DNA and RNA sequences that determine the amino acid sequences used in the synthesis of an organism's proteins. It is the biochemical basis of heredity and nearly universal in all organisms.
2. The set of 64 codons corresponding to the 20 amino acids used for protein synthesis and as the signals for starting and stopping protein synthesis.
genetic coding n.
genetic codeGenetics A sequence of nucleotides, coded in triplets/codons along the mRNA, that determines the sequence of amino acids in a protein; a gene's DNA sequence can be used to predict an mRNA sequence; the 'words' and 'language' that govern the way in which genetic information–DNA is 'written' in the genome and translated into the proteins that perform the genes' activities. See Amino acid, Code, Codon, DNA, Gene, DNA sequence, Nucleotide, Protein, RNA.
ge·net·ic code(jĕ-net'ik kōd)
The genetic information carried by the specific DNA molecules of the chromosomes; specifically, the system whereby particular combinations of three consecutive nucleotides in a DNA molecule control the insertion of one particular amino acid in equivalent places in a protein molecule.