Gene Interactions - Chapter 26

These flashcards cover key concepts from Chapter 26: Gene Interactions, including definitions of terms related to genetics and inheritance patterns.

Gene Interactions

The phenomena where genes at different loci affect the same phenotype, potentially altering Mendelian ratios.

Dihybrid Cross

A genetic cross between individuals that differ in two traits controlled by different loci.

Mendel's Second Law

Also known as the Law of Independent Assortment; states that alleles for different traits assort independently during gamete formation.

Phenotypic Ratio 9:3:3:1

The expected ratio of phenotypes from a dihybrid cross under the assumption of independent assortment.

Recessive Epistasis

A situation where one allele at one locus masks the expression of alleles at another locus, leading to a modified phenotypic ratio.

Dominant Epistasis

When a dominant allele at one locus masks the effects of alleles at a second locus, producing a distinct phenotypic ratio.

Complementary Gene Action

A genetic interaction where the function of two different genes is necessary to produce a particular phenotype.

Penetrance

The proportion of individuals with a specific genotype that exhibit the associated phenotype; can be complete or incomplete.

Expressivity

The degree to which a phenotype is expressed in an individual; reflects the variability in phenotype among individuals with the same genotype.

Chi-square test (χ2 Test)

A statistical test used to determine whether the observed frequencies of phenotypes in a sample deviate from expected frequencies.