Question

What data would you expect to see regarding the distribution of phenotypes from a cross of purple pea plants that are heterozygous for flower color and plant height? (Purple is dominant to white; dwarf is dominant to tall.)

- plant height

Answer 1

In a cross between heterozygous purple pea plants, regarding plant height where dwarf is dominant, a Punnett square reveals a 3:1 phenotypic ratio of dwarf to tall offspring.

Step-by-step explanation:

In a cross between purple pea plants that are heterozygous for flower color and plant height, where purple is dominant to white and dwarf is dominant to tall, you would expect to see a phenotypic distribution that reflects the inheritance of these two traits.

To predict the outcomes, we use a Punnett square: a tool for determining the probability of an offspring having a particular genotype given the genotypes of the parents.

Assuming we are only considering plant height in this scenario and using 'D' to signify the dominant dwarf allele and 'd' for the recessive tall allele, the cross would involve heterozygous parents (Dd x Dd).

Creating a Punnett square for the dihybrid cross of the plant height trait (Dd x Dd) would result in four possible genotype combinations: DD, Dd, Dd, and dd. The phenotypic ratio derived from this Punnett square would be:

• 3 dwarf (DD or Dd)
• 1 tall (dd)

Thus, we predict a 3:1 phenotypic ratio in the offspring for the dominant dwarf trait over the recessive tall trait.