BIO 206 MIDTERM 2 QUESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+||BRAND NEW

BIO 206 MIDTERM 2 QUESTIONS AND CORRECT DETAILED
ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED
A+||BRAND NEW
What is Linkage Equilibrium Ans✓✓✓-random association of alleles at
2 or more loci
-can't predict


Linkage disequilibrium Ans✓✓✓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? Ans✓✓✓-calculated from
"haplotype" (multi locus genotype) frequencies


If linkage disequilibrium is completely linked it will equal to:
Ans✓✓✓+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:
Ans✓✓✓0


If linkage disequilibrium is partially linked it will equal to:
Ans✓✓✓e.g.: +0.10

, How do we test for deviations from linkage equilibrium? Ans✓✓✓-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
Ans✓✓✓F(AB)= F(A) x F(B)
-linkage disequilibrium can then be tested by X^2


Crohns Disease: is it IRF1 or IL5? Ans✓✓✓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? Ans✓✓✓1. physical linkage
2. selection on multilocus genotypes
3. genetic drift
4. population admixture


examples of physical linkage Ans✓✓✓linkage mapping of human
chromosome 22