Introduction to Quantitative Genetics

Definitions

Discontinuous traits - traits with only a few possible phenotypes that fall into discrete classes; phenotype is controlled by one or only a few genes (ex.: tall or short pea plants; red, pink or white snapdragon flowers)

Continuous traits - do not fall into discrete classes; a segregating population will show a continuous distribution of phenotypes

Quantitative trait - more common term for continuous trait; a trait that has a quantitative value (yield, IQ)

Quantitative Genetics - the field of genetics that studies quantitative traits

Quantitative traits are controlled by multiple genes, each segregating according to Mendel's laws. These traits can also be affected by the environment to varying degrees.