QUIZ 4 Flashcards
Dominance would be suggested by which of the following phenotypic ratios among the progeny of a monohybrid cross?
3:1
Below is a biochemical pathway in which the A, B and C genes control the production of cpd2, cpd3 and the final product respectively. Which results are consistent with this pathway?
A B C
cpd1 -> cpd2 -> cpd3 -> final product
mutant a/a will grow if provided with cpd2
The mutation that results in sickle cell anemia, in which the sixth amino acid of the B-globin protein (glutamic acid) is replaced with another amino acid (valine), is an example of:
a missense mutation
There is a mutation that results in a protein that is expressed at higher levels or is hyperactive. This mutant allele is:
hypermorphic
To study vision in fruit flies, Jessie isolated blind fruit fly mutants. Two mutations, r and t, map to the same chromosome. In a complementation test, the r and t mutations complement each other. Think about the progeny of that complementation test. How would you write their genotype?
Rt/rT
For Qs 6-10, marigold flowers come in several colors that are produced in a pathway. Wild-type flowers are red, r/r mutants are orange, d/d mutants are gold, and r/r; d/d double mutants are orange. Think about the pathway of flower color production and the order of gene action. Which
R converts orange to gold
From a dihybrid cross involving the R and D genes, what proportion of offspring plants do you predict would have orange flowers?
4/16
Pick the best genotype of those orange offspring plants.
r/r; -/-
A new mutation e causes marigolds to no thave red flowers; instead, they have yellow flowers. You suspect that e is a new mutation in the D gene. what cross would you perform to test that?
e/e x d/d
What flower color in the offspring plants from the cross above would indicate that e is not a mutation in the D gene?
red
