Complex traits Flashcards
The interaction of many genes + many environmental factors is known as…
The multifactorial hypothesis of complex traits.
What visual method converts continuous data into discrete data?
A histogram.
Is variance in the original units, or squared units?
Squared units.
What type of distribution do complex traits usually follow?
A normal distribution.
When there is no dominance, gene action is…
Additive.
Define broad-sense heritability.
The phenotypic variance explained by genetics.
What measure tells us how well a trait responds to selective breeding?
Narrow-sense heritability.
Low heritability means no genetic involvement. True or false?
False.
Heritability is useful for interpreting differences between populations. True or false?
False.
What is the opposite of a complex trait?
A Mendelian trait.
What study design is commonly used to estimate broad-sense heritability?
Twin studies.
What are two reasons twin studies are not 100% valid?
- Environments cannot be randomised.
- Twin separation may take months or years.
Does higher additive gene action increase heritability?
Yes.
What term refers to the genes that contribute to a complex trait?
Quantitative trait loci (QTL).
Would a backcross of a quantitative trait show a continuous or Mendelian phenotypic range?
Continuous.
As we can’t backcross humans, what method do we use instead?
Association mapping.
For QTL mapping, what could we use as genetic markers?
SNPs or microsatellites.
What does Vg consist of?
Vg = Va + Vd + Vi (or simply Vg = Va)
