Exam 22: The Genetics of Complex Traits

A SNP that can exist as a C or G is associated with a human disease.The genotypic odds ratio of the homozygote CC relative to the homozygote GG is 2.2, which indicates that

A SNP that can be either A or T is associated with a human disease.In the Case population, there were 2000 A alleles and 1500 T alleles.In the Control population, there were 2500 A alleles and 3000 T alleles.The allelic odds ratio indicates that the presence of an A confers a ________ times greater risk for the disease than does the T allele.

In a GWAS experiment, 500,000 SNPs across the genome are genotyped in thousands of Case and Control individuals.Which statistical analysis should be applied and why?

A farmer performs truncation selection to try to increase the weight of peaches in his orchard.Which statement correctly describes a possible outcome of this selection?

When the results of a GWAS experiment using 500,000 SNPs are plotted in a Manhattan plot, significantly associated SNPs are

If a trait is heritable, then individuals with a genetic relatedness of 0.5 are expected to

During truncation selection, the realized heritability of a trait depends on the selection differential, which is the difference between the average trait value of the selected parents and the average trait value of the entire parental population.

By definition, linkage disequilibrium means that

Typically, multiple interacting genes and the environment contribute to a complex quantitative trait, resulting in

The genetic relatedness of two siblings is

Complex quantitative traits often show

Most complex quantitative traits

Introgressions are used to

Twins from two individual zygotes (dizygotic twins)

In an experiment to distinguish genetic versus environmental effects on a trait, the test individuals

The total phenotype variance (V_P)is

Broad-sense heritability is defined as

To test for statistical significance of the association of a SNP with a trait, the null hypothesis in a chi-square test for independence is that the one of the SNP alleles is more common in the Cases than in the Controls.

Which of the following is not true about monozygotic twins?