Non-mendelian genetics

Complete dominance (normal mendelian inheritance)

In heterozygous individuals, one trait is expressed and the other is completely hidden

Codominance

A condition in which both alleles for a gene are fully expressed- results in spots/speckles

incomplete dominance

Situation in which one allele is not completely dominant over another allele- a blend of the alleles is present

lethal alleles

Mutated alleles, when 2 are inherited, are capable of causing death.

polygenic inheritance

combined effect of two or more genes on a trait

multiple alleles

three or more forms of a gene that code for a single trait

X-linked traits

genes located on the X chromosome

Pleiotropy

The ability of a single gene to have multiple effects/traits

Epistasis

A type of gene interaction in which one gene controls the expression of another gene

example of x-linked trait

color blindness

example of co-dominance

black and white speckled hens

example of epistasis

laborador retrievers

Carrier

A person whose genotype includes a allele that is not expressed in the phenotype.

Pedigree

A diagram that shows the occurrence of a genetic trait in

heterozygote advantage

Greater reproductive success of heterozygous individuals compared to homozygotes; tends to preserve variation in gene pools.

Gene

A segment of DNA on a chromosome that codes for a specific trait

gene locus

specific location of a gene on a chromosome

dihybrid cross

Cross or mating between organisms involving two pairs of contrasting traits

Gamete

A haploid cell such as an egg or sperm. Gametes unite during sexual reproduction to produce a diploid zygote.