Lecture 9- Advanced Mendelian Genetics

Question 1

Epistasis

Answer 1

The expression of one gene is modified (e.g. masked, inhibited or suppressed) by the expression of one or more other genes.

Question 2

Epistasis example

Answer 2

Agouti mice- coat colour, agouti gene is turned on and off

Question 3

Modifier genes

Answer 3

Affect the phenotype or expression of other genes

Question 4

Penetrance

Answer 4

the extent to which a particular gene or set of genes is expressed in an individual

Question 5

Expressivity

Answer 5

degree of phenotypic change produced by a genotype

Question 6

Incomplete penetrance-Huntington’s disease

Answer 6

Not all individuals develop phenotype
Incomplete penetrance due to variable expressivity

Question 7

Genetic map

Answer 7

Based on mapping genes relative to each other or another feature in the genome
Show positions but not an actual scale

Question 8

Physical maps

Answer 8

Complete DNA sequence of a genome with positions of gens mapped

Question 9

Linkage

Answer 9

Alleles that are close together on the same chromosome tend to be passed on together to offspring

Question 10

Recombination

Answer 10

Pieces of DNA are broken and recombined to produce new combinations of alleles
Varies depending on distance between genes