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Tweaking the Experiment
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First Experiment: The first four questions pertain to the experiment depicted in Figure 2-5 that involves a P cross between tall and dwarf plants. Questions 5 and 6 involve other possible types of P crosses such as those shown in the data.



1

If an F1 tall plant were crossed to a P generation dwarf plant, the percentage of dwarf offspring that would be expected is
A)100%
B)50%
C)25%
D)0%
2

If the F1 offspring had been crossed to each other instead of self fertilized, the ratio of tall to dwarf would have been
A)3:1
B)1:1
C)1:3
D)All tall
3

If two tall plants of the F2 generation were chosen and crossed to each other, the ratio of tall to dwarf offspring would be
A)All tall
B)3:1
C)All tall or 3:1
D)1:1
4

If Mendel randomly chose many F2 plants without regard to their phenotypes, and crossed them to each other, what would be the expected ratio of tall to dwarf plants?
A)All tall
B)1:1
C)1:3
D)3:1
5

In the P cross involving plants with green and yellow seeds, what would have been the expected number of yellow seeds in the F2 generation if Mendel had counted 1200 seeds?
A)1200
B)900
C)600
D)300
6

In the P cross involving flower position, what would have been the expected ratio of axial to terminal flowers in the F2 generation if the axial trait had been recessive to terminal?
A)1 axial:3 terminal
B)1 axial:1 terminal
C)3 axial:1 terminal
D)All terminal

Second Experiment: Questions 7-9 pertain to the experiment depicted in Figure 2-8 that involves a P cross between plants with yellow, round seeds to plants with green, wrinkled seeds. Questions 10, 11 and 12 involve other possible types of crosses.



7

If an F1 plant was crossed to a plant with green, wrinkled seeds, what would have been the predicted ratio of F2 seeds in the following phenotypic categories: yellow and round, yellow and wrinkled, green and round, and green and wrinkled?
A)9:3:3:1
B)1:1:1:1
C)3:9:3:1
D)1:3:3:1
8

If the F1 offspring had been crossed to each other instead of self fertilized, what would have been the predicted ratio of F2 seeds in the following phenotypic categories: yellow and round, yellow and wrinkled, green and round, and green and wrinkled?
A)9:3:3:1
B)1:1:1:1
C)3:9:3:1
D)1:3:3:1
9

If two plants of the F1 generation were chosen and crossed to each other, the ratio of round to wrinkled seeds in the F2 generation would be
A)All round
B)3:1
C)All wrinkled
D)1:1
10

A dihybrid cross involved a parental generation consisting of true-breeding tall plants with white flowers and true-breeding dwarf plants with purple flowers. Tall and purple are dominant traits. If the F1 generation was self-fertilized, what would be the ratio of offspring in the F2 generation with the following phenotypes: tall with purple flowers, tall with white flowers, dwarf with purple flowers, and dwarf with white flowers?
A)1:1:1:1
B)3:1:1:3
C)1:3:3:1
D)9:3:3:1
11

In the cross described in question 10, what would have been the expected number of tall plants with white flowers in the F2 generation if Mendel had counted 3200 seeds?
A)1800
B)900
C)600
D)200
12

A P cross involves three traits. A true-breeding tall plant with purple, axial flowers was crossed to a true-breeding dwarf plant with white, terminal flowers. The F1 generation plants were allowed to self-fertilize. What would be the predicted ratio of the F2 generation with regard to the following phenotypes involving two traits: tall with axial flowers, dwarf with terminal flowers, tall with terminal flowers, and dwarf with axial flowers?
A)1:1:1:1
B)3:9:3:1
C)9:1:3:3
D)9:3:3:1







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