Crossing a true-breeding red-flowered snapdragon with a true-breeding white-flowered snapdragon produces all pink snapdragons in the F₁ generation.If F₁ individuals are crossed,what will be the ratio of phenotypes in the F₂ generation?

Question

Quizplus · Accepted Answer

When the F₁ individuals (all pink) are crossed, their genotype can be represented as Rr (where R=red allele and r=white allele). When these individuals undergo segregation during meiosis, the possible gametes they can produce are R and r.

Thus, the possible genotypes of the F₂ individuals are: RR, Rr, rR, and rr.
 
The corresponding phenotypes are: red, pink, pink, and white.

A Punnett square can be used to determine the expected ratio of phenotypes in the F₂ generation:

|   | R   | r   |
|---|---|---|
| R | RR | Rr |
| r | rR | rr |

From the Punnett square, it can be seen that the expected ratio of phenotypes is 1 red: 2 pink: 1 white. Therefore, the best choice is C.

Crossing a True-Breeding Red-Flowered Snapdragon with a True-Breeding White-Flowered Snapdragon