Question

Genotype of a plant bearing purple flowers is PP and one with white flowers is pp. when

these are crossed,

a) What colour of the flowers would you find in the F1 progeny?

b) Give percentage of white flowered plants when F1 plant are self-pollinated.

c) What is the ratio of Pp and PP in F2 generation?

d) Draw a flowchart to depict the cross.​

Answer 1

Answer:

 monohybrid cross is a mating between two individuals with different alleles at one genetic locus of interest. 

The cross between PP (purple flowers) and pp (white flowers) will produce pea plant having purple flowers having genotype Pp. P would be a dominant trait and p is a recessive trait, therefore plants having Pp genotype would be of purple colored. 

Answer 2

The types of progeny are as follows.

• When a plant bearing purple flowers with genotype 'PP' is crossed with white flowers with genotype 'pp', the monohybrid cross will result in all purple flowers in the F1 progeny.
• When the flowers of the F1 progeny are self-pollinated, the ratio of purple flowers to white flowers in the F2 generation will be 3:1. Hence, percentage of white flowered plants will be 25%.
• The different genotypes obtained in F2 after self-pollination of F1 hybrids are PP, (Pp×2) and pp. This ratio is 1:2:1. Hence, ratio of Pp to PP is 2:1.