In peas, blue flowers are dominant over white. If pure breeding blue is crossed with pure breeding white, what are the genotype and phenotype of the F1 generation? What are the expected genotypic and

The F1 generation produces only blue flowers from a cross between pure breeding blue and pure breeding white plants. This indicates that blue flower color is dominant over white flower color.

Let:

• 'B' represent the dominant allele for blue flowers.
• 'b' represent the recessive allele for white flowers.

Parental genotypes:

• Pure breeding blue flower plant: BB
• Pure breeding white flower plant: bb

• Parental Cross (P generation): $$\text{BB (Blue)} \times \text{bb (White)}$$
• Gametes: $$\text{B} \quad \text{b}$$
• F1 Generation Genotype: All offspring will inherit 'B' from the blue parent and 'b' from the white parent. $$\text{Bb}$$
• F1 Generation Phenotype: Since 'B' (blue) is dominant, all F1 plants will express the blue flower phenotype. $$\text{Blue flowers}$$

a) The possible genotype in the F1 plants is $\boxed{\text{Bb}}$ and the possible phenotype is $\boxed{\text{Blue flowers}}$.

To determine the expected flowers and ratios, we perform a cross between two F1 individuals (F1 $\times$ F1).

• F1 Cross: $$\text{Bb (Blue)} \times \text{Bb (Blue)}$$
• Gametes from each F1 parent: $$\text{B, b}$$
• Cross Diagram (Punnett Square for F2 generation): $$\begin{array}{|c|c|c|} \hline \text{Gametes} & \text{B} & \text{b} \\ \hline \text{B} & \text{BB} & \text{Bb} \\ \hline \text{b} & \text{Bb} & \text{bb} \\ \hline \end{array}$$
• Expected F2 Genotypes:
  • BB: 1
  • Bb: 2
  • bb: 1
• Expected F2 Phenotypes:
  • Blue flowers (BB, Bb): 3
  • White flowers (bb): 1

b) The type of flowers expected in the F2 generation are Blue flowers and White flowers.
The genotypic ratio is $\boxed{1 \text{ BB} : 2 \text{ Bb} : 1 \text{ bb}}$.
The phenotypic ratio is $\boxed{3 \text{ Blue} : 1 \text{ White}}$.