In radishes,long or round are homozygous forms of an incompletely dominant gene,and oval is the phenotype of the heterozygote.If a long radish is crossed with a round radish,which of the following phenotypic ratios of the F2 generation is correct?
A) all round
B) all oval
C) 1/2 long, 1/2 oval
D) 1 long, 2 oval, 1 round
E) 1/2 oval, 1/2 round

Question

In radishes,long or round are homozygous forms of an incompletely dominant gene,and oval is the phenotype of the heterozygote.If a long radish is crossed with a round radish,which of the following phenotypic ratios of the F2 generation is correct?  
A) all round
B) all oval
C) 1/2 long, 1/2 oval
D) 1 long, 2 oval, 1 round
E) 1/2 oval, 1/2 round

Quizplus · Accepted Answer

When a long radish (homozygous) is crossed with a round radish (homozygous), all of their F1 offspring will be oval (heterozygous).

The genotype of the F1 offspring will be Ll.

When the F1 hybrid plants self-fertilize, the possible genotypes and phenotypes of the F2 offspring can be determined using a Punnett square:

|   | L | l |
|---|---|---|
| L | LL | Ll |
| l | Ll | ll |

From the Punnett square, we can see that the phenotypic ratio of the F2 offspring will be:
1 long: 2 oval: 1 round

Therefore, choice D is correct.

In Radishes,long or Round Are Homozygous Forms of an Incompletely