Question

A blue colour flower plant denoted by BB is crossbred with a white colour flower plant denoted by ww.; (a) State the colour of flower we would expectintheirF1 progeny.; (b)Write the percentage of plants bearing white flower inF2generation when the flowers ofF1 plants were selfed.; (c) State the expected ratio of the genotype BB and Bw intheF2progeny.(All India - 2013)

Answer 1

Answer:

I can't understand the question

Answer 2

The correct answer is:

Explanation:

• Genotype of the blue flower plant: BB
• Gamete of the blue flower plant: B
• Genotype of the white flower plant: ww
• Gamete of the white flower plant: w
• Crossing blue and white flower plant, we get the following F1 progeny:

                                                          B

                                                  w    Bw

• The progeny Bw has a heterozygous genotype.
• If we consider the blue colour to be dominant over the white colour, then BB and Bw genotypes will be dominant over the ww genotype.
• Both BB and Bw genotype will develop blue colour and ww genotype will develop white colour.

(a) The colour of the F1 progeny with genotype Bw will be Blue.

• Gametes formed by F1 progeny: B and w.
• Selfing the F1 progenies,

                                                        B       w

                                                B    BB     Bw

                                                      (B)      (B)

                                                w    Bw     ww

                                                       (B)     (W)

• (B) stands for blue colour.
• (W) stands for white colour.

(b) Percentage of plants with white flowers in F2 generation: $\frac{1}{4} \times 100 =25\%$

(c) Ratio of BB and Bw genotypes in the F2 progeny = 1 : 2.