Question

In a cross of two F1-hybrid plants with purple flowers and round seeds (PpRr), what fraction of the offspring should have purple flowers and round seeds (purple flowers and round seeds are the dominant traits)?In a cross of two F1-hybrid plants with purple flowers and round seeds (PpRr), what fraction of the offspring should have purple flowers and round seeds (purple flowers and round seeds are the dominant traits)?

a. 9/16b. 1/12c. 1/16d. 3/16e. 12/16

Answer 1

1. a. 9/16 will have purple flowers and round seeds.

Step-by-step explanation:

If purple flowers (P) and round seeds (R) are the dominant traits and both genes follow Mendel's principles, the cross between two heterozygous (PpRr) will always produce the following proportions:

9/16 of both dominant traits (in this example, purple flowers, and round seeds)

3/16 of one dominant trait and one recessive (For example, non-purple flowers and round seeds)

9/16 of the other dominant trait and the other recessive one (purple flowers and non-round seeds)

1/16 of double recessive (non-purple flowers and round seeds).

In the attached Punnett Square is this cross, and it can be seen genotypic and phenotypic proportions.