Question

Tallness (T) in snapdragons is dominant to dwarfness (t), and red (R) flower color is dominant to white (r). The heterozygous condition results in pink (Rr) flower color. If snapdragons are heterozygous for height as well as for flower color, a mating between them will result in what ratio?A) 9:4:3B) 1:2:1C) 27:9:9:9:3:3:3:1D) 9:3:3:1E) 6:3:3:2:1:1

Answer 1

Answer:

E. 6:3:3:2:1:1

Explanation:

Look at the attached picture to see the Punnett square for your problem.

The cross for this is snapdragons who are heterozygous for both traits so the cross would be:

TtRr x TtRr

As you can see in the image, you have the following genotype combinations with the corresponding phenotype combinations:

GENTOTYPE       PHENOTYPE            NUMBER

TTRR                    Tall - Red                        1

TtRR                     Tall - Red                        2

TTRr                     Tall - Pink                       2

TtRr                      Tall - Pink                       4

TTrr                      Tall - White                     1

Ttrr                       Tall - White                     2

ttRR                      Short - Red                     1  

ttRr                       Short - Pink                    2

ttrr                        Short - White                  1

The following phenotype combinations in summary would then be:

Tall - Pink:     6

Tall - Red:      3

Tall - White:   3

Short - Pink:   2

Short - White: 1

Short - Red:   1

So the ratio is 9:3:3:2:1:1