Chapter 24 Study Guide: Quantitative Traits and Heritability

Vocabulary flashcards covering quantitative traits, variance components, and heritability concepts from Chapter 24.

Quantitative trait

A trait that shows a continuous distribution and is influenced by multiple genes and environmental factors.

Continuous distribution

A distribution where trait values span a range rather than falling into discrete categories.

Polygenic

Influenced by many genes contributing to the phenotype.

Environmental factors

Non-genetic factors that influence trait expression and cause phenotypic variability.

Genetic variance

The portion of phenotypic variance due to genetic differences among individuals.

Additive variance

Genetic variance due to additive effects of alleles across loci.

Dominance variance

Genetic variance arising from interactions between alleles at the same locus.

Environmental variance

Phenotypic variance caused by non-genetic factors like climate, soil quality, and management.

Heritability (H^2)

The proportion of phenotypic variance in a population attributable to genetic differences.

Interpretation of high heritability

Indicates a strong genetic contribution to observed variation but does not mean the trait is fully genetically determined.

Height (as an example)

A quantitative trait influenced by both genetics and environment (e.g., nutrition).