Chapter 18

Give three examples of a complex trait.

Explain why complex traits are often called quantitative traits.

Name several factors that influence variation in complex traits.

Explain why it does not make sense to try to separate the effects of genes \((\)"nature") and the environment ("nurture") in a single individual.

Explain why the effect of genotype on a phenotype cannot always be determined without knowing what the environment is, and why the effect af a particular environment on a phenotype cannoe always be determined without knowing the underlying genotype.

Define what is meant by "regression toward the mean."

Define the heritability of a trait and explain why it depends on the population being studied.

Define concordance and explain how twin studies can be used to investigate the important of genetic and environmental factors in the expression of a trait.

For a typical complex trait, describe the relationship between the number of genes affecting the trait and the magnitude of their effects on the trait.

Explain what personalized medicine is and how it relates to complex traits such as human diseases.