A gene that is expressed only when it is matched with a similar gene from the other parent. go to glossary index

a gene that, on its own, is usually over-ridden by the dominant gene and therefore not expressed in physical characteristics. Two such genes, one from each parent, must be present in a kitten for the characteristic caused by this gene to be displayed. Examples of recessive genes are those for blue or chocolate coat color.

A genetic disorder that appears only in patients who have received two copies of a mutant gene, one from each parent.

a gene that does not produce its effect when it occurs with a dominant gene, but produces its effect only when there are two copies of it

A gene which is the weaker of a pair and whose characteristic is only expressed if paired with another recessive gene for the same characteristic. (See also Autosomal Recessive Disorder)

A gene that must be paired with one identical to it in order to determine a trait in the phenotype.

If paired with a Dominant gene, the message of the recessive gene will not be expressed. However, if paired with another recessive gene, then the message will be expressed.

an allele that occurs only when two (r) are present in genetic make up (ex. Albino Ball Python, Axanthic Trans Pecos Rat Snake).

gene that produces its characteristic phenotype only when its allele is identical; "the recessive gene for blue eyes"

A gene that is phenotypically expressed only when homozygous.

gene that requires two copies (one inherited from each parent) to cause the trait to express (see also dominant gene).

A gene which will be expressed only if there are 2 identical copies or, for a male, if one copy is present on the X chromosome.

a gene which is hidden by a dominant gene; it must be present on both chromosomes in a pair (one from the father, one from the mother) to show outward signs of the characteristic.

A gene which has little effect on the phenotype of a plant when it is paired up with a corresponding dominant gene.

a gene that requires a second identical gene in order to be expressed

Recessive genes affect the phenotype only when present in a homozygous condition. Recessive genes must be received from both parents before the phenotype caused by the recessive genes can be observed.

A gene that can be expressed only when both members of a chromosome pair contain the same allele for a given characteristic (i.e., the same allele must be inherited from both the dam and the sire).

A gene that will be expressed only when there are two identical copies (homozygous). For example, a dog can only be red (brown) when it carries both genes for red. If it has one black, it will be a black dog. See also dominant gene.

A gene which must be present on both chromosomes in a pair to show outward signs of a certain characteristic.

A gene that is not "expressed" in the presence of a dominant gene and only determines how the offspring will develop if it is "homozygous."

A gene that is phenotypically expressed in the homozygous state but has its expression masked in the presence of a dominant gene.

A type of gene that is not expressed as a trait unless inherited by both parents.

an allele that can determine the phenotype only when in homozygous state.

In genetics, the term "recessive gene" refers to an allele that causes a phenotype (visible or detectable characteristic) that is only seen in a homozygous genotype (an organism that has two copies of the same allele) and never in a heterozygous genotype. Every person has two copies of every gene on autosomal chromosomes, one from mother and one from father. If a genetic trait is recessive, a person needs to inherit two copies of the gene for the trait to be expressed.