Quantitative Genetics

Question 1

What is quantitative genetics

Answer 1

Study of evolutionary properties of traits under polygenic inheritance

Question 2

Quantitative traits may be 3 things

Answer 2

1. Continuous
2. Metristic
3. Threshold

Question 3

Meristic

Answer 3

Things we count

Question 4

Threshold

Answer 4

There is a limit

Question 5

Variation of population with environment involved equation

Answer 5

Vp=Vg+Ve+Vgxe

Question 6

Lots of environmental variation on 1 locus makes it what

Answer 6

Continuous, just like if there were many loci working on a trait

Question 7

3 ways to determine genetic basis of quantitative traits

Answer 7

1. Quantitative trust locus (QTL) mapping
2. Candidate genes
3. Heritability

Question 8

QTL mapping

Answer 8

Start w 2 phenotypes 
Create linkage map w neutral markers
Cross phenotypes to produce F1
Cross F1 to produce F2
Score F2 for phenotype and marker loci
See if there is a trait diff between marker genotypes and how much variation is associated with each marker

Question 9

Candidate genes

Answer 9

Genes whose functions are known in other organisms

Question 10

Heritability (broad sense)

Answer 10

Proportion of phenotypic variation due to individual genetic variation
Hb =Vg/Vp

Question 11

Vg has additive variations Va+Vd+Vi. What are they

Answer 11

Va=variation due to effects of alleles that are independent of effects of other alleles at same or other loci
Vd= dominant effects
Vi= inter-locus interactions

Vd and vi result in deviations from correlation between parents and offspring

Question 12

Narrow sense heritability

Answer 12

Proportion of phenotypic variation due to additive genetic variation
HN=h2=Va/Vp
Regression line from parent/offspring regressions
Lets us predict response to selection