Genetics MCM Unit 1

Question 1

phase

Answer 1

whether or not you know if two loci are from the same parent/on same chromosome

same DNA strand = cis/coupling
different chromosome/parent = repulsion/trans

Question 2

indirect linkage testing

Answer 2

direct is measuring the disease gene itself

indirect - use a flag/allele/marker that is nearby if the disease gene loci is uncertain

Question 3

recombination

Answer 3

by crossing over during meiosis

-happens if 2 locuses are not on the same gene or are too far apart on a large gene

Question 4

haplotype

Answer 4

genes/loci close enough together than they undergo meiosis together and dont cross over

Question 5

linkage disequilibrium

Answer 5

co-segregation of linked genes

Question 6

recombination distance

Answer 6

1 cM = 1% chance of crossing over

Question 7

polymorphism vs rare genetic variant

Answer 7

polymorphism - at least 2% frequency of an allele

rare genetic variant - allele with less than 1% frequency

Question 8

SNP vs. microsatellites

Answer 8

microsatellite - variable number of tandem repeats. more useful as a marker for indirect testing

SNP - single nucleotide polymorphism

Question 9

3 classes of mutation

Answer 9

linked extragenic
intragenic
disease - causing mutation