Consider the following cross involving the genes for pod color and seed shape:
P generation:
Green pods with round seeds= ____
Yellow pods with wrinkled seeds=____
F1 generation:
1/4 green pods with round seeds= ____
1/4 grens pods with wrinkled seeds=____
1/4 yellow pods with round seeds=____
1/4 yellow pods with wrinkled seeds=____
Options:
Aa Bb
aa bb
Aa bb
aa Bb
AA BB
Aa BB
aa BB
A_ BB
AA Bb
A_ Bb
AA bb
A_ bb
AA B_
Aa B_
aa B_
A_ B_
Remember that the upper-case letter corresponds to the allele with the dominant phenotype. Use the symbols "A" and "a" for pod color and the letters "B" and "b" for seed shape.
In some cases, an individual's genotype could be either "AA" or "Aa" and the data provided do not allow you to distinguish between these possibilities. In that case, we will use the shorthand "A_" to represent "AA or Aa".
The only way that you can get a F1 generation with the phenotype that was described is if the cross between the P1 generation genotypes are Aa Bb x aa bb producing an F1 generation of 1/4-AaBb, 1/4-Aabb, 1/4-aaBb, and 1/4-aabb.
What letter represents the dominant yellow allele
To determine the genotype of the P generation and the F1 generation, we need to analyze the results of the cross.
P generation:
Green pods with round seeds = A_ B_
Yellow pods with wrinkled seeds = aa bb
Based on the information given, we know that the genotype of the P generation for pod color (A_) could either be homozygous (AA) or heterozygous (Aa) since both would result in the dominant phenotype (green pods). Therefore, we represent the genotype with "A_".
Next, we move on to the F1 generation:
1/4 green pods with round seeds = A_ B_
1/4 green pods with wrinkled seeds = A_ bb
1/4 yellow pods with round seeds = aa B_
1/4 yellow pods with wrinkled seeds = aa bb
From the F1 generation, we can see that both green pods and yellow pods are present, indicating that the P generation is heterozygous for pod color (Aa). We can now update the genotypes as follows:
P generation:
Green pods with round seeds = Aa Bb
Yellow pods with wrinkled seeds = aa bb
Thus, the correct option for the P generation would be: Aa Bb
Now, for the F1 generation:
1/4 green pods with round seeds = Aa B_
1/4 green pods with wrinkled seeds = Aa bb
1/4 yellow pods with round seeds = aa B_
1/4 yellow pods with wrinkled seeds = aa bb
The correct option for the F1 generation would be: Aa Bb
Therefore, the correct answer is: Aa Bb