Albino - having absent or deficient melanin. Widely used term for "amelanistic". See tyrosinase-negative and tyrosinase-positive.
Allele - either of the two paired genes which affect an inheritable trait.
Amelanistic - having no melanin.
Anerythristic - having no red color.
Axanthic- having no yellow color.
Codominant - a gene that causes the homozygous form to look different than the wild-type and the heterozygous form to have traits of both.
Dihybrid Cross - shows the possible genotype of offspring as the result of the pairing of two different genes.
DNA (Deoxyribonucleic Acid) - molecules bearing genetic information of all living cells. Gene. Also referred to as "unit of inheritance".
Dominant - a gene that causes an animal to look different than the wild-type and where the homozygous form and the heterozygous form look the same as each other.
Double Heterozygous - being heterozygous for two different traits.
Gene - unit of heredity that determines the characteristics of the offspring.
Genetics - the study of heredity.
Genotype– an organism’s genetic composition. Heredity - the transmission of genetic characters from parents to offspring.
Het – an abbreviation for heterozygous.
Heterozygous – possessing two different genes for a given trait. An animal with one mutated, recessive gene still appears normal; its mutated gene can be inherited by future offspring. A codominant animal is heterozygous for the dominant form of its mutated gene, yet is different in appearance than both the wild-type and homozygous forms.
Homozygous – A state in which both genes for a specific trait are the same. When a recessive gene is it its homozygous form, it makes the animal look different from the wild-type. When a dominant gene is in its homozygous state, it causes the animal to look different from both the wild-type and the heterozygous (codominant) forms.
Hypomelanistic- an animal having less black and/or brown color than a wild-type.
Leucistic- a pure white animal with dark eyes.
Locus - a gene's position on a chromosome (plural: loci).
Melanin - black or brown skin pigments.
Melanistic - abnormally dark, especially due to an increase of melanin.
Mutation - an abnormal gene that under certain circumstances can cause an animal to be born with an appearance other than wild-type.
Normal - an animal with no mutated genes - "wild type" in appearance. (See wild type).
Phenotype - an animal's external apperance, as caused by its genotype.
Possible Het - an animal from a known breeding that has either a 50% or 66% possibility of being "heterozygous" for a mutant gene.
A 66% possible het comes from breeding 2 heterozygous animals together: 50% of the offspring are heterozygous, 25% will be homozygous, and 25% will be wild-type. Of the normal appearing animals, 66% (or roughly 2 out of 3) will actually be heterozygous for the mutated gene.
A 50% possible het comes from breeding a heterozygous animal to a wild-type animal. All of the resulting offspring will be wild-type in appearance, but 50% of them will actually be heterozygous for the mutated gene and must be bred out to determine which animals are really hets.
Recessive - a gene that affects an animal's appearance if it's present in the homozygous state. A heterozygous animal carrying a mutated, recessive gene looks normal.
Super - commonly used herpetocultural term for the dominant form of a co-dominant mutation. i.e. Super Motley.
Tyrosinase - an enzyme required for synthesizing melanin.
Tyrosinase-negative - an albino whose cells lack tyrosinase, producing a white and yellow/orange animal with pink eyes. A separate albino mutation from tyrosinase-positive. Also called T-.
Tyrosinase-positive- an albino not able to synthesize melanin, but capable of synthesizing tyrosinase. Also referred to as T+.
Wild-type - the way the animal usually looks in nature (i.e. the normal color and pattern).
Xanthic - having more yellow color than wild-type.