locus

Trait

...ne to the centromere is referred to as the gene's locus or map location. A chromosomal region known to co...identified is referred to as a quantitative trait locus . The nucleus of a diploid cell contains two of each chromosome, with homologous (mostly identic...

Blood type

...hesus Rh (or the D antigen) is inherited on one locus (on the short arm of the first chromosome, 1p36.2-p34) with two alleles, of which Rh+ is dominant and Rh- recessive. The gene codes for a polypeptide on the red cell membrane. Rh- individuals ( dd genotype) do not produce this antigen, and may be ...

Microsatellite

...TAGTAG..." The number of repeats at a particular locus is hypervariable (highly polymorphic ) between individuals of the same species. It is for this reason that microsatellite sequences can be used for genetic fingerprinting and paternity testing . Most loci of the genome, even non-coding parts, w...

Locus

The word locus (plural loci ) is Latin for "place". In biology and evolutionary computation , a locus is the position of a gene (or other significant sequence) on a chromosome . A locus can be occu...

Homozygote

... or polyploid and have the same alleles at a locus (position) on homologous chromosomes .When an o...zygous dominant genotype occurs when a particular locus comprises two alleles for the dominant trait (e.g. AA ).A homozygous recessive genotype occurs ...

Human

...ionist view); or that they also have minds , the locus of, or another word for, consciousness (roughly ...ing, Stephen. 2004. "Genetic variation at the MC1R locus and the time since loss of human body hair." Current Anthropology 45 (1): 105-108. Sagan, Carl...

Heterozygote

...or polyploid and have different alleles at a locus (position) on homologous chromosomes . When an organism is referred to as a heterozygote, or being heterozygous for a specific gene , it means that the organism carries two different versions of that gene on the two corresponding chromosomes...

Hardy-Weinberg principle

...ting , the genotype frequencies at a single gene locus will become fixed at a particular equilibrium val... at that locus. In the simplest case of a single locus with two alleles A and a with allele frequencies of p and q , respectively, the HWP predicts ...

Genetic fingerprinting

...e different numbers of microsatellites at a given locus . By using PCR to detect the number of repeats at several loci, it is possible to establish a match that is extremely unlikely to have arisen by coincidence. Genetic fingerprinting is used in forensic science , to match suspects to samples of blo...

Gene pool

...n . When many alleles exist for a given gene or locus , a population is said to be polymorphic with respect to that gene or locus. When no variation exists, it is labelled monomorphic . See also genetic drift small population size population genetics For the guitarist named Gene...

Gene duplication

...ay be removed from one copy and now the other gene locus is free to mutate and discover new functions. Alternatively, the gene may acquire deleterious mutations and become a pseudogene . The postulate that gene duplication has a major role in evolution was developed in the 1980s and is now widely acc...

Gene

...y present in two or more copies. The location (or locus ) of a gene and the chromosome on which it is situated is in a sense arbitrary. Genes that appear together on the chromosomes of one species, such as humans, may appear on separate chromosomes in another species, such as mice. Two genes positioned ne...

Ewens's sampling formula

...lassified according to the gene at a particular locus then the probability that there are a 1 all...d genetic drift and the role of selection at the locus in question is negligible, and (3) every mutant allele is novel. This is a probability distributio...

Evolutionary developmental biology

...cular cellular or biochemical function at one locus , leaving the duplicated locus free to fulfill a new function. In contrast, changes in gene regulation , is a "second-order" effec...

Chromosomal crossover

...ent end piece. If they break at the same place or locus in the sequence of base pairs, the result is an exchange of genes . This outcome is the normal way for crossover to occur. If they break at slightly different loci, the result can be a duplication of genes on one chromosome and a deletion of these...

Bacterial conjugation

...mation, the F-plasmid carries a tra and a trb locus , which together are about 33 kb long and consist of about 40 genes . The tra locus includes the pilin gene and controlling genes, which together form pili on the cell surface, pol...

Allele frequency

...d as follows: Given a) a particular chromosome locus , b) a gene occupying that locus, c) a populatio...are ten individuals in a population and at a given locus there are two possible alleles, A and a , then if the genotypes of the individuals are: AA ,...

Allele

...native forms of the same gene occupying a given locus (position) on a chromosome . An example is the gene for blossom color in many species of flower - a single gene controls the color of the petals, but there may be several different versions of the gene. One version might result in red petals, whi...