Question

Punnet and his colleagues mated a purebred purple flower, long pollen sweet pea with a pure-bred red flower, round pollen sweet pea and obtained an F1 with purple flower and long pollen. What mating should they do to determine the recombination frequency between the gene that controls the color of the flower and the gene that controls the shape of the pollen?

Answer 1

Cross an individual of the F1 with the purebred red flower, round pollen sweet pea parental.

Step-by-step explanation:

The parental individuals are:

• PL/PL: purebred purple flower, long pollen sweet pea
• pl/pl: pure-bred red flower, round pollen sweet pea

The resulting F1 of the cross between the different parental types can only be PL/pl, which has purple flowers and long pollen. This means that the purple flower (P) and long pollen (L) traits are dominant.

To determine the recombination frequency between genes P/p and L/l, the cross should be done between a heterozygous individual for both genes (the F1) and a homozygous recessive individual for both traits (the pl/pl parental). This is called a test cross.