Homozygote

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

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 occupied by any of the alleles of the ...

Allele frequency

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

Bacterial conjugation

... other genetic information, 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 ...

Evolutionary developmental biology

... fixation of a particular cellular or biochemical function at one locus , leaving the duplicated locus free to fulfill a new function. In contrast, changes in gene regulation , ...

Ewens's sampling formula

... from a population and classified according to the gene at a particular locus then the probability that there are a 1 alleles represented once ... under mutation and genetic drift and the role of selection at the locus in question is negligible, and (3) every mutant allele is novel. This is ...

Hardy-Weinberg principle

... generation of random mating , the genotype frequencies at a single gene locus will become fixed at a particular equilibrium value. It also specifies ... the allele frequencies at that locus. In the simplest case of a single locus with two alleles A and a with allele frequencies of p and q , ...

Human

... physicalist or reductionist view); or that they also have minds , the locus of, or another word for, consciousness (roughly the dualist ... Iltis, David; and Wooding, Stephen. 2004. "Genetic variation at the MC1R locus and the time since loss of human body hair." Current Anthropology 45 ...

Trait

... ; the distance from a gene to the centromere is referred to as the gene's locus or map location. A chromosomal region known to control a trait while the ... gene within not being identified is referred to as a quantitative trait locus . The nucleus of a diploid cell contains two of each chromosome, with ...

Allele

... An allele is any one of a number of alternative 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, ...

Chromosomal crossover

... two homologous instances of the same chromosome, break and then reconnect but to the different 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 ...

Gene

... genome of an organism, which in many species is divided among several chromosomes and typically 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 ...

Gene duplication

... , most mutations will lead to the death of the organism. When a gene is duplicated selection may 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 ...

Gene pool

... and population bottlenecks ) can cause reduced fitness and an increased chance of extinction . 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 ...

Genetic fingerprinting

... variable repeating sequences called microsatellites . Two unrelated humans will be likely to have 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 ...

Heterozygote

... Heterozygote cells are diploid 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 ...

Microsatellite

... if one sequenced a microsatellite locus, one would expect to see a sequence of ... 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 ...

Blood type

... is very common in populations of Asian descent, but rare in ones of European descent.) Rhesus 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 ...