Chapter 12: Extensions Of Mendelian Genetic Analysis

These flashcards cover key vocabulary and concepts regarding extensions of Mendelian genetic analysis as presented in the lecture notes.

Multiple Alleles

Many genes have more than two forms (alleles); however, a diploid individual can only carry two alleles.

ABO Blood Groups

Blood groups determined by three alleles (IA, IB, i), resulting in four phenotypes (A, B, AB, O).

Codominance

A form of inheritance in which both alleles contribute to the phenotype, as seen in the ABO blood group.

Epistasis

A genetic interaction where one gene masks the expression of another gene.

Incomplete Dominance

An allelic relationship where the heterozygote's phenotype is intermediate between the two homozygous phenotypes.

Heterozygote

An individual having two different alleles for a specific gene.

Penetrance

The degree to which a genotype manifests a particular phenotype.

Expressivity

The degree to which a genotype is expressed in the phenotype among individuals.

Recessive Epistasis

A form of epistasis where a homozygous recessive genotype at one locus masks the expression of another locus.

Dominant Epistasis

A situation where a dominant allele at one locus masks the expression of alleles at another locus.

Phenocopy

A trait that appears to be genetically caused but is actually caused by environmental factors.

Essential Genes

Genes that are necessary for survival; mutations can result in lethality.

Dihybrid Cross

A genetic cross between individuals that examines two traits.

Duplicate Dominant Epistasis

A genetic interaction where either of two dominant alleles can produce one phenotype.

Duplication Recessive Epistasis

An interaction where recessive alleles at two different loci lead to a specific phenotype.

Mendelian Ratios

Predicted ratios of offspring produced from genetic crosses based on Mendelian inheritance.

Wild-type

The typical form of a gene or organism found in nature.

Genotype

The genetic constitution of an individual.

Phenotype

The observable physical or biochemical characteristics of an organism.