Andy

Question 1

What is pleiotropy?

Answer 1

One locus affects two or more traits

Question 2

What is epistasis?

Answer 2

Alleles at one locus affect the expression of alleles at a different locus

Question 3

What is linkage?

Answer 3

Two or more loci are on the same chromosome

Question 4

What are the requirements of the Hardy Weinberg equilibrium to be applicable?

Answer 4

Large random mating population
In the absence of:
- migration
- mutation
- selection

Question 5

What is migration?

Answer 5

The movement of alleles from one population to another

Question 6

What does the proportion of alleles in the new population depend on

Answer 6

• immigration rate
• difference in allele frequencies between the two populations

Question 7

What is selection?

Answer 7

The process that determines which individuals become the parents of the next generation

Question 8

What is natural selection

Answer 8

the environment deciding which individuals are the parents of the next generation (adapt or perish)

Question 9

What is artificial selection?

Answer 9

Humans decide which individuals are the parents of the next generation (goal oriented)

Question 10

Qualitative traits vs quantitative traits

Answer 10

Qualitative
- controlled by one or few loci
- discrete phenotypes (eye colour, coat colour etc.)
Quantitative
- controlled by multiple loci
- continuous phenotypes (height, weight, racing speed, milk yield, temperament) - assign categories based on perceived thresholds

Question 11

What are threshold traits

Answer 11

quantitative traits that are controlled by many genes, categorized by small number of discrete phenotypic classes

Question 12

What is variance?

Answer 12

A measure of how much variability there is within a population for a certain trait

Question 13

What are the three genetic components?

Answer 13

• additive (A): a measure of the sum of effects of individual alleles
• dominance (D): a measure of the combined dominance effects of individual loci
• interaction (I): a measure of the combined interactions between loci (epistasis)

Question 14

What is heritability?

Answer 14

Proportion of total variance that is additive genetic and 1/2 is transmitted from parent to offspring (h^2) (proportion of phenotype that is passed on from generation to generation)

Question 15

What are the three heritability ranges?

Answer 15

low 1-20% - reproduction and fitness traits
medium 20-35% - performance traits, some aspects of temperament
high 35% and up - conformation traits, growth and body composition traits