A student analyzed ears of corn that demonstrated two traits in the F2 kernels, purple or white colors and smooth or wrinkled shapes. A tabulation of 135 individual kernels gave the following results: purple and smooth = 75 white and smooth = 28 purple and wrinkled = 24 white and wrinkled = 8 What would be the only phenotype present in the F1 generation?

Respuesta :

The answer is purple and smooth.

It is known that the in dihybrid cross (a cross between two different traits), the phenotypic ratio between the offspring of two heterozygous parents in the F2 generation is 9:3:3:1.

purple and smooth = 75                (≈ 9 · 8)

white and smooth = 28                  (≈ 3 · 8)

purple and wrinkled = 24               (= 3 · 8)

white and wrinkled = 8                   (= 1 · 8)


So, the ratio between the offspring is close to 9:3:3:1 in F2 generation.


This means, that the only heterozygotes are present in the F1 generation, and they must be purple and smooth.

i can confirm that purple and smooth is the right answer, i had three tries on this assignment and chose all the other ones. so this means that purple and smooth is the only other answer left. have a good day. c: