Questions -
Q1. You are a new plant breeder trying to improve hard spring wheat (a self-pollinated plant) in North Dakota. You are breeding for two traits, Russian Wheat Aphid (RWA) resistance and yellow rust (Yr) resistance (you want to select plants that are RWA-resistant and Yr-resistant). You have made the following cross:
RWA-resistant, Yr-susceptible / RWA-susceptible, Yr-resistant
The F1 is: RWA-susceptible, Yr-resistant
True or False:
At least one gene(s) for Yr-resistance is dominant.
Q2. The F1 in problem 1 is RWA-susceptible, Yr-resistant. You have selfed the F1 to produce an F2 population. You score Yr resistance in 1000 F2 plants. You find 750 resistant plants to 250 susceptible plants.
Genes at how many loci control Yr resistance?
a) 1 locus
b) 2 loci
c) 3 loci
d) 4 loci
Q3. The F1 in problem 1 is RWA-susceptible, Yr-resistant. You have selfed the F1 to produce an F2 population. You score RWA resistance in 1000 F2 plants. You find 936 susceptible plants to 64 resistant plants.
Genes at how many loci control RWA resistance?
a) 1 locus
b) 2 loci
c) 3 loci
d) 4 loci
Q4. You summarize your F2 data for both RWA and Yr resistance traits in questions 1 - 3. Out of the 1000 F2 plants, how many will be both RWA-resistant and Yr-resistant? Assume the traits/loci are independent of each other?
a) 256
b) 128
c) 64
d) 48
e) 12
Q5. You have crossed an awnless, bronze-chaffed wheat with an awned, white-chaffed wheat. The F1 plant is awnless and bronze-chaffed. Assume that awns and chaff color are each controlled by a single, indpendent loci.
What is the expected frequency of awned, white-chaffed genotypes in the F6 generation?
a) 0.125
b) 0.234
c) 0.333
d) 0.675
Q6. You find the following phenotypic ratio 9 : 18 : 9 : 7 : 14 : 7 for traits of interest in the F2 population. Assuming all loci are segregating independently, how many segregating loci likely explain these results?
a) 1 locus
b) 2 loci
c) 3 loci
d) 4 loci
Q7. If you are breeding using the pedigree system and wanted to determine the genetics of a trait, which would you most likely use:
a) Test Cross
b) Progeny Test
c) Selection
d) None of the above
Q8. You have made the following cross:
AABBccDDEE x AAbbCCDDee.
Start by writing out the genotype of the F1.
What proportion of F4 individuals will be homozygous in the F4 generation?
a) 0.375
b) 0.485
c) 0.563
d) 0.670
e) 0.875
Q9. You have made a cross between two parents, each of which carries two dominant alleles for resistance to common bunt, and important disease of wheat. There are a total of four dominant alleles segregating in your population. Assume the alleles segregate independently.
What proportion of plants in the F4 generation will be homozygous at all 4 loci?
a) 0.068
b) 0.125
c) 0.375
d) 0.586
e) 0.794
Q10. True/False: The pivotal process of plant breeding, recombination and segregation of genetic materials, occurs during meiosis.