Beyond Alleles: Quantitative Genetics

Question 1

Compare and contrast broad and narrow sense heritability.

Question 2

Measure narrow sense heritability using an offspring-parrent regression.

Question 3

Use the Breeder’s Equation (R=h^2S) and explain each component and how it is measured.

Question 4

Describe linkage disequilibrium and its role in Genome-Wide Association (GWA) studies and Quantitative trait locus (QTL) mapping.

Question 5

Be able to explain how a QTL mapping study is done.

Question 6

Define Polygenic Trait

Answer 6

A trait that is influenced by many genetic loci.
Interaction between alleles (epistasis)
Interaction with environment (phenotypic plasticity)
Polygenic traits tend to vary continuously among individuals.

Question 7

Define Quantitative Genetics

Answer 7

The study of the genetic mechanisms and evolution of continuous phenotypic traits.

Question 8

Board Sense Heritability (H^2)

Answer 8

Proportion of the total phenotypic variation of a trait that is attributable to genetic differences among individuals.

Question 9

Narrow sense heritability (h^2)

Answer 9

Proportion of phenotypic variance explained by the additive effects of alleles.

Question 10

What does an offspring–parent regression show?
A. broad sense heritability
B. the frequency of alleles in the population
C. how closely the offspring trait values resemble those of
their parents
D. the effect of drift on the phenotypes of the offspring
represented in a population

Answer 10

C. How closely the offspring trait values resemble those of their parents.

Question 11

When can the non-additive interactions among alleles that
affect phenotypes be transmitted from parent to offspring?
A. when organisms do not reproduce sexually
B. only when organisms reproduce sexually
C. Never; the non-additive interactions among alleles
cannot be passed from one generation to the next.
D. Always; this occurs any time an organism reproduces.

Answer 11

A. When organisms do not reproduce sexually.

Question 12

A selection differential is the measure of the
A. strength of phenotypic selection.
B. allelic variation in the population.
C. strength of selection on the genes.
D. strength of drift on the population.

Answer 12

A. Strength of phenotypic selection