【文章內(nèi)容簡介】 on is the simultaneous correction of two sites during gene conversion.Coding strand of DNA has the same sequence as mRNA.Codominant alleles both contribute to the phenotype。 neither is dominant over the other.Coevolution —see concerted evolution.Cognate tRNAs are those recognized by a particular aminoacytRNA synthetase.Coointegrate structure is produced by fusion of two replicons, one originally possessing a transposon, the other lacking it。 the cointegrate has copies of the transposon present at both junctions of the replicons, oriented as directrepeats.Coldsensitive mutant is defective at low temperature but functional at normal temlperature.Colony hybridization is a technique for using in situ hybridization to identify bacteria carrying chimeric vectors whose inserted DNA is homologous with some particular sequence.Compatibility group of plasmids contains members unable to coexist in the same bacterial cell.Complementation refers to the ability of independent (nonallelic)genes to provide diffusible products that produce wild phenotype when two mutants are tested in trans configuration in a heterozygote.In vitro plementation assay consists of identifying a ponent of a widtype cell that can confer activity on an extract prepared from a mutant cell. The assay identifies the ponent rendered inactive by the mutation.Complementation group is a series of mutations unable to plement when tested in pairwise binations in trans。 defines a genetic unit (the cistron) that might better be called a nonplex mentation group.Complex locus (of D. melanogaster) has genetic properties inconsistent with the function of a gene representing a single protein. Complex loci are usually very large (100kb) at the molecular level. Complexity is the total length of different sequences of DNA present in a given preparation. Compostie transposons have a central region flanked on each side by insertion sequences, either or both of which may enable the entire element to transpose.Concatemer of DNA consists of a series of unit genomes repeated in tandem.Concatenated circles of DNA are interlocked like rings one a chain.Concerted evolution describes the ability of two related genes to evolve together as though constituting a single locus.Condensation reaction is one in which a covalent bond is formed with loss of a water molecule, as in the addition of an amino acid to a polypeptide chain.Conditional lethal mlutations kill a cell or virus under certain (nonpermissive) conditions, but allow it to survive under other (permissive) conditions.Conjugation describes ‘mathing’ between two bacterial cells, when (part of ) the chromosome is transferred from one to the other.Consensus sequence is an idealized sequence in which each position represents the base most often found when many actual sequences are pared.Conservative rebination involves breakage and reunion of preexisting strands of DNA without any synthesis of new stretches of DNA.Conservative transposition refers to the movement of large elements, originally classified as transposons, but now considered to be episomes. The mechanism of movement resembles that of phage lambda.Constant regions of immunoglobulins are coded by C genes and are the parts of the chain that vary least. Those of heavy chains identify the type of immunoglobulin.Constitutive genes are expressed as a function of the interaction of RNA polymerase with the promoter, without additional regulation。 sometimes also called household genes in the context of describing functions expressed in all cells at a low level.Constitutive heterochromatin describes the inert state of permanently nonexpressed sequences, usually satellite DNA.Constitutive mutations cause genes that usually are regulated to be expressed without regulation.Contractile ring is a ring of actin filaments that forms around the equator at the end of mitosis and is responsible for pinching the daughter cells apart.Controlling elements of maize are transposable units originally identified solely by their genetic properties. They may be autonomous (able to transpose independently) or nonautonomous (able to element).Coordinate regulation refers to the mon control of a group of genes.Cordycepin is 3’ deoxyadenosine, an inhibitor of polyadenylation of RNA.Core DNA is the bp of DNA contained on a core particle.Core particle is a digestion product of the nucleosome that retains the histone octamer and has bp of DNA。 its structure appears similar to that of the nucleosome itself.Corepressor is a small molecule that triggers repression of transcription by binding to a regulator protein.Cosmids are plasmids into which phage lambda cos sites have been inserted。 as a result, the plasmid DNA can be packaged in vitro in the phage coat.Cot is the product of DNA concentration and time of incubation in a reassociation reaction.Cot is the Cot required to proceed to half pletion of the reaction。 it is directly proportional to the unique length of reassociating DNA.Cotransfection is the simultaneous transfection of two markers.Crossingover describes the reciprocal exchange of material between chromosomes that occurs during meiosis and is responsible for genetic rebination.Crossover fixation refers to a possible consequence of unequal crossingover that allows a mutation in one member of a tandem cluster to spread through the whole cluster (or to be eliminated).Cruciform is the structure produced at inverted repeats of DNA if the repeated sequence pairs with its plement on the same strand (instead of with its regular partner in the other strand of the duplex).Cryptic satellite is a satellite DNA sequence not identified as such by a separate peak on a density gradient。 that is, it remains present in mainband DNA.ctDNA is chloroplast DNA.Cyclic AMP (cAMP) is a molecule of AMP in which the phosphate group is joined to both the 3’ and 5’ positions of the ribose。 its binding