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.