Bio 206 midterm 2 eXAm WitH CorreCt ACtUAL QUeStioNS
ANd CorreCtLY WeLL deFiNed ANSWerS LAteSt ALreAdY
GrAded A+
What is Linkage Equilibrium - ANSWer--random association of alleles at 2 or more loci
-can't predict
Linkage disequilibrium - ANSWer-in nonrandom association of alleles at two or more loci
**NOT THE SAME AS LINKAGE
-linkage is 2 genes that are physically linked
How is linkage disequilibrium calculated? - ANSWer--calculated from "haplotype" (multi locus genotype)
frequencies
If linkage disequilibrium is completely linked it will equal to: - ANSWer-+0.25 or -0.25
Anything that gets very close to positive or negative 0.25 means the more closely linked they are
If linkage disequilibrium is completely unlinked it will equal to: - ANSWer-0
If linkage disequilibrium is partially linked it will equal to: - ANSWer-e.g.: +0.10
How do we test for deviations from linkage equilibrium? - ANSWer--can be estimated from the products
of the frequencies of the constituent alleles by the hardy Weinberg theorem:
, *test for deviations from linkage equilibrium by looking at expected haplotype frequencies at linkage
equilibrium
Equation for testing for deviations from linkage equilibrium - ANSWer-F(AB)= F(A) x F(B)
-linkage disequilibrium can then be tested by X^2
Crohns Disease: is it IRF1 or IL5? - ANSWer-the connections between AET and Crohns appears to be a
spurious result of LD
-crohns maybe maintained by the benefits of L503
What causes linkage disequilibrium? - ANSWer-1. physical linkage
2. selection on multilocus genotypes
3. genetic drift
4. population admixture
examples of physical linkage - ANSWer-linkage mapping of human chromosome 22
examples of genetic drift - ANSWer-mutations from 'A' to 'a' on an Ab chromosome
examples of population admixture - ANSWer-human hair and eye colour
selection at linked loci has 4 potential maladaptive results in: - ANSWer-1. "associative over dominance"
2. "Background selection"
3. "genetic hitchhiking"
4. a "selective sweep"
ANd CorreCtLY WeLL deFiNed ANSWerS LAteSt ALreAdY
GrAded A+
What is Linkage Equilibrium - ANSWer--random association of alleles at 2 or more loci
-can't predict
Linkage disequilibrium - ANSWer-in nonrandom association of alleles at two or more loci
**NOT THE SAME AS LINKAGE
-linkage is 2 genes that are physically linked
How is linkage disequilibrium calculated? - ANSWer--calculated from "haplotype" (multi locus genotype)
frequencies
If linkage disequilibrium is completely linked it will equal to: - ANSWer-+0.25 or -0.25
Anything that gets very close to positive or negative 0.25 means the more closely linked they are
If linkage disequilibrium is completely unlinked it will equal to: - ANSWer-0
If linkage disequilibrium is partially linked it will equal to: - ANSWer-e.g.: +0.10
How do we test for deviations from linkage equilibrium? - ANSWer--can be estimated from the products
of the frequencies of the constituent alleles by the hardy Weinberg theorem:
, *test for deviations from linkage equilibrium by looking at expected haplotype frequencies at linkage
equilibrium
Equation for testing for deviations from linkage equilibrium - ANSWer-F(AB)= F(A) x F(B)
-linkage disequilibrium can then be tested by X^2
Crohns Disease: is it IRF1 or IL5? - ANSWer-the connections between AET and Crohns appears to be a
spurious result of LD
-crohns maybe maintained by the benefits of L503
What causes linkage disequilibrium? - ANSWer-1. physical linkage
2. selection on multilocus genotypes
3. genetic drift
4. population admixture
examples of physical linkage - ANSWer-linkage mapping of human chromosome 22
examples of genetic drift - ANSWer-mutations from 'A' to 'a' on an Ab chromosome
examples of population admixture - ANSWer-human hair and eye colour
selection at linked loci has 4 potential maladaptive results in: - ANSWer-1. "associative over dominance"
2. "Background selection"
3. "genetic hitchhiking"
4. a "selective sweep"
