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 Fn) 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