Q1. TAM107 was a very important wheat in the history of the Southern Great Plains. Its pedigree is TAM105*4/Amigo.

Which of the following crossing histories are consistent with this pedigree?

a. TAM105/3/TAM105//TAM105/Amigo/4/TAM105

b. TAM105/Amigo//Amigo/3/Amigo/4/Amigo

c. Amigo/TAM105//TAM105/3/TAM105/4/TAM105

d. TAM105/3/Amigo//TAM105/Amigo/4/TAM105

Q2. You are a new plant breeder trying to improve soybean (a self-pollinated plant). You breeding for two traits, nematode resistance and white flowers (you want to select plants that are white flowered and nematode resistant). You have made the following cross:

White flowered, nematode susceptible x Yellow flowered, nematode resistant

The F₁ is: Yellow flowered, nematode resistant.

At least one gene for yellow flower color is:

At least one gene for nematode resistance is:

CHOICES: Dominant, Recessive

Q3. You self the F₁ in problem 2 (yellow flowered, nematode resistant) and score the 1000 F₂ plants. Considering flower color: you find 750 yellow flowered plants to 250 white flowered plants.

Genes at how many loci control flower color?

a. 1 locus

b. 2 loci

c. 3 loci

d. 4 loci

Q4. You self the F₁ in problems 2 (yellow flowered, nematode resistant) and score the 1000 F₂ plants. Considering nematode resistance: you find 937 nematode resistant plants to 63 nematode susceptible plants.

Genes at how many loci control nematode resistance?

a. 1 locus

b. 2 loci

c. 3 loci

d. 4 loci

Q5. You summarize your F₂ data for both traits in questions 3 and 4. Out of the 1000 F₂ plants, how many will be white flowered and nematode resistant?

Assume the traits/loci are independent of each other.

a. 235

b. 250

c. 687

d. 703

e. 937

Q6. You self all of the 1000 plants in your F₂ population (in problems 3, 4, 5) for three more generations. In the F₅ generation, you score 1000 plants. What is the number of plants are homozygous at the loci controlling flower color and nematode resistance?

a. 250

b. 703

c. 109

d. 824

e. 937

Q7. What proportion of the homozygous individuals will be homozygous at all loci for white flowers and nematode resistance?

a. 1/2 or 0.5

b. 1/4 or 0.25

c. 1/8

d. 1/16

e. 1/32

f. 1/64

Q8. In the F₅ generation of Problem 6, how will the frequency of homozygous nematode resistant, white flowered plants (homozygous) compare to frequency of phenotypically nematode resistant, white flowered plants (total)?

a. homozygous < total

b. homozygous = total

c. homozygous > total

Q9. Theoretically, the complete genotypic array could be obtained in a single seed descent population segregating for alleles at 7 loci with a minimum population size of:

a. 7 plants

b. 14 plants

c. 128 plants

d. 2187 plants

e. 16384 plants

Q10. The phenotype is determined only by the environment in which plants are grown.

True

False

Q11. In a CMS-based hybrid breeding effort:

The A-line must be in a sterile cytoplasm, and the B and R-lines must be in a fertile cytoplasm.

True

False

Q12. Genotypic ratios change with each generation of inbreeding. For example, the genotypic ratio of an F₂ is different from the genotypic ratio in the F₅.

True

False

Q13. You find the following phenotypic ratio 9 : 18 : 9 : 7 : 14 : 7 for traits of interest in the F₂ population. How many segregating loci explain these results?

a. 1 locus

b. 2 loci

c. 3 loci

d. 4 loci

Q14. With 6 segregating loci in an F₁, how many different gametes will be produced?

a. 1

b. 6

c. 64

d. 128

e. 256

Q15. In a cross between two inbred lines, you score 816 F₂ plants. You find 79 plants are the double recessive class (aabb). Were the parents genes independent, in coupling, or in repulsion phase?

a. Independent

b. Coupling phase

c. Repulsion phase

Q16. In a cross between two inbred lines, you score 816 F₂ plants. You find 79 plants are the double recessive class (aabb). How many crossover units (map units) separate the A and B loci?

a. 4

b. 10

c. 14

d. 24

e. 38

f. 50

g. the genes are not linked.

Q17. Dr. Baenziger released the wheat variety 'Millennium' with this pedigree:

Arapahoe/Abilene/4/Colt/3/Warrior*5/ Agent//Kavkaz

Identify the parents used to make the cross that produced Millennium.

Female Parent

Male Parent

Choices: Agent//Kavkaz, Arapaho/Abilene, Arapahoe/Abilene/4/Colt/3/Warrior, Colt/3/Warrior*5/Agent//Kavkaz, Colt

Q18. Identify the breeding method that corresponds to each of the following descriptions:

Method that involves quantities of seed sufficient for evaluation of early generations (low F_n) in multiple environments.

Method that provides genetic information to the breeder from each generation of selection.

Method used for targeted addition of specific trait(s) to improve an elite breeding line or cultivar.

Method for producing the gametic array of genotypes

Choices: Bulk breeding method, pedigree breeding method, single-seed descent method, backcross breeding method, mix-n-match breeding method, multiline breeding method

Q19. You are running a hard wheat backcrossing program to introgress a key gene for stem rust resistance, Sr46, from a wild relative. Linked to the stem rust gene is an undesirable grain softness gene (Pin). Sr46 and the grain softness locus (Pin) are 9 map units apart. What is the probability of eliminating the grain softness gene after 6 backcrosses? The recurrent parent is sr46sr46pinpin and the donor parent is Sr46Sr46PinPin.

a. 0.63

b. 0.53

c. 0.43

d. 0.35

e. 0.27

f. 0.18

Q20. Heritability of a trait is the same in every population.

True

False