I. Allelic and Genic Interactions

II. Sex Determination

III. Linkage:

1) Consider the results from test cross: AaBb x aabb:

- assume complete dominance for each locus.

AB = 23

Ab = 9

aB = 6

ab = 18

Conduct a Chi-Square test of independence to determine whether the genes are linked or are assorting independently. Use the p = 0.05 level of significance to evaluate the null hypothesis, with the associated critical Chi-Square value (from the table) of 3.84. If the genes are linked, show the arrangement of alleles on the chromosomes in the AaBb parent, and show the distance between the loci.

2) Consider these results from a testcross: DdEe x ddee

- assume complete dominance for each locus

DE = 14

De = 22

dE = 28

de = 10

Conduct a Chi-Square test of independence to determine whether the genes are linked or are assorting independently. Use the p = 0.05 level of significance to evaluate the null hypothesis, with the associated critical Chi-Square value (from the table) of 3.84. If the genes are linked, show the arrangement of alleles on the chromosomes in the AaBb parent, and show the distance between the loci.

3) Consider these results from a testcross: FfGg x ffgg

- assume complete dominance for each locus

FG = 45

Fg = 43

fG = 12

fg = 10

Conduct a Chi-Square test of independence to determine whether the genes are linked or are assorting independently. Use the p = 0.05 level of significance to evaluate the null hypothesis, with the associated critical Chi-Square value (from the table) of 3.84. If the genes are linked, show the arrangement of alleles on the chromosomes in the AaBb parent, and show the distance between the loci. If they are assorting independently, think of ANOTH REASON why the results deviant from a typical 1:1:1:1 ratio. Examine the ratios of each locus by itself. Anything screwy?

4) Consider these results from a testcross: AaBbDd x aabbdd

- assume complete dominance for each locus.

ABD = 24

ABd = 40

AbD = 75

Abd = 125

aBD = 132

aBd = 84

abD = 30

abd = 10

Suppose you know the loci are on the same chromosome as a consequence of previous research. Show the arrangement of alleles on the chromosomes in the AaBbDd parent, and show the distance between the loci.

5) What is the "Interference Coefficient" between these loci?