Question

A blue colour flower plant denoted by BB is cross bred with that of white colour flower denoted by bb.
1)State the colour of flower you would expect in their F1 generation plants.
2)what must be the percentage of white flower plants in f2 generation if F1 plants are self-pollinated?
3)State the expected ratio of the genotypes BB and bbin the F2 progeny.

Answer 1

1)all the flowers would be in blue (as BB signifies that the flower colour is dominant )
2)if there are 4 flowers......then one would be of colour white (in 100%.....white is 25%)
hope it helps

Answer 2

The following questions can be answered as follows:

(1) The colour of the flower expected in the F1 generation will be blue since blue colour is dominant (BB) over white (bb) and a cross between homozygous dominant and homozygous recessive (BB x bb) results in the formation of all flowers with Bb genotype where blue colour will dominate.

Thus, blue coloured flowers are expected in F1 generation.

(2) If the plants obtained in the F1 generation are self pollinated (Bb x Bb), it will result in 25% of the progeny as white flowers, since 25% of the offspring will have a homozygous recessive gene (bb).

Thus, 25% of F2 generation are expected to be white flower plants.

(3) The expected ratio of the BB genotype will be 1/4 (25%) and expected ratio of bb genotypes will be 1/4 (25%) in the F2 progeny.