AGRI 03382 Study Guide - Quiz Guide: Chionanthus Virginicus, Ailanthus Altissima, Cercis Canadensis

Butterflies have a Z/W mechanism of sex determination. In thissystem, females are the heterogametic sex, so females are ZW andmales are ZZ. Papilio glaucus, the Eastern Tiger Swallowtail, isfound throughout the eastern United States. Papilio canadensis, theCanadian Tiger Swallowtail, is found throughout Southern Canada andthe Northern United States. The two species are known to hybridizewhere their ranges overlap near the Great Lakes. For butterfliesliving in seasonal environments, it is important to correctly timethe diapause – a state of physiological dormancy that allows themto survive the winter. P. canadensis lives in colder climates andtherefore has only one generation per year and an obligatediapause; all pupae of this species diapause from late fall untilthe next spring, when they resume development. In P. glaucus, mostpupae diapause only in response to cold temperatures; as long asweather remains warm, they continue to develop. However, some P.glaucus pupae show obligate diapause similar to P. canadensis. Thegene that controls diapause in Papilio is located on the Zchromosome, and obligate diapause is specified by the recessiveallele ob. A population of P. glaucus near Lake Michigan is atHardy-Weinberg equilibrium. You have found that 9% of the malepupae show obligate diapause. You now bring P. canadensis and P.glaucus back to the lab to carry out some controlled crosses. TheP. canadensis population that you chose is fixed for the ob allele.The P. glaucus population that you chose is fixed for thealternative dominant allele at this locus that allows forenvironmental determination of diapause.

From the following matings, what is the frequency of diapausingpupae that you would expect? (Show how you calculated this).

All the info has been given

(2 points) Male canadensis x Female glaucus

Males:

Females:

(2 points) Male glaucus x Female canadensis

Males:

Females:

P.glaucus is highly palatable to predators. Females come in twoforms: a yellow form that looks identical to males and has somelevel of crypsis and a dark form, which mimics the unpalatablebutterfly Battus philenor. This trait is specific to females andthe locus that determines the phenotype is biallelic and located onthe W-chromosome.

(1 point) What form of mimicry is this?

(3 points) You are comparing two populations of P.glaucus foundin different regions. What factors do you think might influence therelative fitness of the two morphs?

(1 point) What type of selection would you expect to act on thegene responsible for color morph determination? (check one)

Negative Frequency Dependent Selection

Positive Frequency Dependent Selection

Balancing Selection

Directional Selection

*The normal color of snapdragons is red. Some pure lines showing variation in flower color have been found. Analyze the following crosses and do the following:²

Explain the inheritance of these colors (include number of genes, alleles and dominance relationships).

Determine the genotypes of the parents and the F₁ of each cross.

Propose a biochemical pathway for flower color production in snapdragons.

Parents F₁ F₂

1. orange x yellow orange 3 orange: 1 yellow

2. red x orange red 3 red: 1 orange

3. red x yellow red 3 red: 1 yellow

4. red x white red 3 red: 1 white

5. yellow x white red 9 red: 3 yellow: 4 white

6. orange x white red 9 red: 3 orange: 4 white

7. red x white red 9 red: 3 yellow: 4 white

You perform a mutant screen for new recessive mutations that produce white eyes in Drosophila. You isolate 5 new mutants. Consider this complementation table (entries indicate the eye color of offspring of crosses of corresponding maternal and paternal genotypes):

How many different mutant genes have you discovered and how do you know?