1. WT has green carpels (i.e. the female reproductive organs). In an EMS-induced mutant population, you have identified a recessive mutant of Arabidopsis with pink carpels, You have named the mutation blusher (bls), and the specific mutant allele bls-1.

A. Based on the number of bls alleles you have isolated, was yours a saturating screen?
a. No
b. Yes

B. How many mutant alleles per gene would you need to identify in a genetic screen, on average, to conclude that you have achieved genome saturation? (0.5 marks)
a. At least 1
b. At least 5
c. Between 6 and 10
d. 2 or more
e. 3 or 4

C. Why can it be assumed that the genome has been saturated for mutations once you identify this average number of mutant alleles per gene?

a. Because of the Poisson formula, which describes the relationship between average number of mutant alleles and number of genes that have not been mutated
b. Because of the Poisson formula, which describes the relationship between average number of mutant alleles and proportion of genes that have been mutated
c. Because of the Poisson formula, which describes the relationship between average number of mutant alleles and proportion of genes that have not been mutated
d. Because of the Poisson formula, which describes the relationship between average number of mutant alleles and number of genes that have been mutated

2. By screening a transposon-induced mutant population, you have found an Arabidopsis, recessive mutant (transposon line no. 3; tl3) that has purple carpels. Both bls-1 and tl3 are sterile at the homozygous state.

A. What experiment would you perform to test whether tl3 is mutated in the BLS gene?
a. EMS mutagenesis
b. Agrobacterium-mediated transformation
c. Transposon mutagenesis
d. Double-mutant analysis
e. Complementation test

B. What are the genotypes and phenotypes of the plants you would use for the experiment in A?
a. Genotype: BLS/BLS; phenotype: green carpels
b. Genotype: bls-1/bls-1; phenotype: pink carpels
c. Genotype: tl3/tl3; phenotype: purple carpels
d, Genotypes: BLS/bls-1 and +/tl3; phenotype: green carpels
e. Genotypes: bls-1/bls-1 and tl3/tl3; phenotypes: pink carpels and purple carpels, respectively

C. How would you determine the genotypes of the plants used in B? (1.5 marks)
a. I would cross each plant to WT, sow the resulting progeny on antibiotic-free medium, and count the number of plants with green, pink or purple carpels
b. I would allow each plant to self-fertilize, sow the resulting progeny on medium with kanamycin, and count the number of kanamycin-resistan and kanamycin-sensitive seedlings
c. Homozygous mutants are sterile; fertile plants with pink or purple carpels would be heterozygous; and plants with green carpels would be homozygous WT
d. I would tross each plant to WT, sow the resulting progeny on medium with kanamycin, and count the number of kanamycin-resistan and kanamycin-sensitive seedlings
e. would allow each plant to self-fertilize, sow the resulting progeny on antibiotic-free medium, and count the number of plants with green, pink or purple carpels

D. What results would you expect from the experiment in A if tl3 were mutated in the BLS gene?
a. 3:1 plants with green carpels to plants with non-green carpels
b. A mutant population in which to screen for the non-green carpel phenotype
c. 3:1 plants with non-green carpels to plants with green carpels
d. A dominant mutant with a non-green carpel phenotype
e. 100% plants with non-green carpels

2. You have found that the non-green carpels of the plants in 1D are neither pink nor purple, but red -i.e. their colour is intermediate between pink and purple.

A. Would you conclude that tl3 is mutated in the BLS gene?
a.Yes
b. No

B. How would you interpret the finding that the non-green carpels of the plants in 1D are red?
a. [The plants with the red carpels are bls-1/bls-1;tl3/tl3 double homozygous mutants, and BLS and TL3 act in overlapping pathways
b. tl3 is mutated in the BLS gene, the plants with the red carpels are bls-1/tl3 transheterozygotes, and the bls-1 mutation results in lower amounts of the BLS WT protein, rather than in WT amounts of a bls mutant protein with lower activity
c. tl3 is mutated in the BLS gene, and the plants with the red carpels are bls-1/tl3 transheterozygotes showing signs of intragenic complementation
d. The plants with the red carpels are TL3/tl3 heterozygotes
e. The plants with the red carpels are BLS/bls-1;TL3/tl3 double heterozygotes

3. In the same EMS screen that has resulted in the identification of the bls mutant (see question of 1), gold you have also identified a recessive mutant with bright-yellow carpels that you have named BLS heart and HOG (hog). You would like to know what the relationship is between the pathways in which turns act, so you generate the bls-1/bls 1;hog/hog double mutant; the bls-1/bls-1;hoglhog double mutant out to have bright-yellow carpels. Based on this result, which interaction best describes the relationship between BLS and hog?

a. BLS and HOG act in independent pathways
b. BLS and HOG act in the same pathway, and BLS acts upstream of HOG
c. BLS and HOG act in overlapping pathways
d BLS and HOG act in the same pathway, and HOG acts upstream of BLS
e. None of the above

1. WT has green carpels (i.e. the female reproductive organs). In a...