57. In a specific cross, F2 progeny exhibit a modified dihybrid ratio of 9 : 6 : 1 (instead of 9 : 3 : 3 : 1).
What phenotypic ratio would be expected from a test-cross with one of the F1 progeny?
A. 1 : 3 : 1 B. 1 : 2 : 1 C. 1 : 1 : 1 D. 2 : 1 : 1 E. 3 : 1 : 1
57. In a specific cross, F2 progeny exhibit a modified dihybrid ratio of 9 : 6 : 1 (instead of 9 : 3 : 3 : 1).
What phenotypic ratio would be expected from a test-cross with one of the F1 progeny?
A. 1 : 3 : 1 B. 1 : 2 : 1 C. 1 : 1 : 1 D. 2 : 1 : 1 E. 3 : 1 : 1
Related textbook solutions
Related questions
1. When determining the relative genetic distance between twogenes, why is dihybrid back-cross preferable over traditionaldihybrid cross?
A. 9:3:3:1 phenotypic ratio is easier to work with than 1:1:1:1ratio. | |
B. Genotypes of the offspring can be determined based on theirphenotype. |
C. If the genes are independently assorted, the dihybridback-cross would result in only 2 genotypes in the F1generation. | |
D. B and C |
A researcher has selfed an autotetraploid plant with the genotype D/D/d/d, and in the resulting progeny she observes a 35:1 phenotypic ratio. What can she conclude from this observation?
| The progeny from this cross do not demonstrate a standard Mendelian phenotypic ratio. | |
| In the 35:1 phenotypic ratio, the 1 represents the phenotype of the d/d/d/d progeny. | |
| During meiosis in the D/D/d/d parent plant, it is likely that only bivalents, no quadrivalents or trivalents, formed. | |
| It is likely that in this plant species, gametes associate with one another randomly. | |
| All of the answers are correct. |
