Get Binteractiveb Transparency B2b Dominant And Recessive Genes - Troup

Working with garden pea plants, Mendel found that crosses between parents that differed for one trait produced F1 offspring that all expressed one parent's traits. The traits that were visible in the F1 generation are referred to as dominant, and traits that disappear in the F1 generation are described as recessive.

Dominant refers to the relationship between two versions of a gene. Individuals receive two versions of each gene, known as alleles, from each parent. If the alleles of a gene are different, one allele will be expressed; it is the dominant gene. The effect of the other allele, called recessive, is masked.

An individual with one dominant and one recessive allele for a gene will have the dominant phenotype. They are generally considered “carriers” of the recessive allele: the recessive allele is there, but the recessive phenotype is not.

For example, in horses, the extension gene determines whether an animal's coat color will be red or black; here, the dominant allele E produces black pigment in the coat, while the recessive allele e produces red pigment.

Dominant and recessive genes. The most common interaction between alleles is a dominant/recessive relationship. An allele of a gene is said to be dominant when it effectively overrules the other (recessive) allele. Eye colour and blood groups are both examples of dominant/recessive gene relationships.

There are two different genotypes and phenotypes—dominant and recessive. Dominant traits are those in which an individual inherits at least one dominant allele. By contrast, recessive traits refer to those in which an individual inherits two recessive alleles.

A person's genotype is their unique sequence of DNA. More specifically, this term is used to refer to the two forms a person has inherited from their mother and father, for a particular gene. Phenotype is the observable expression of this genotype – a person's presentation.

A dominant allele produces a dominant phenotype in individuals who have one copy of the allele, which can come from just one parent. For a recessive allele to produce a recessive phenotype, the individual must have two copies, one from each parent.

In Mendellian genetics, the dominance and recessiveness are used to describe the functional relationship between two alleles of one gene in a heterozygote. The allele which constitutes a phenotypical character over the other is named dominant and the one functionally masked is called recessive.