Question

which cross could be used to determine whether two traits are distributed among offspring independently of each other? a. a plant that is true - breeding for wrinkled yellow seeds is crossed with a plant that is true - breeding for round green seeds. b. a plant that is true - breeding for axial flowers is crossed with a plant that is true - breeding for white flowers. c. a plant that is true - breeding for terminal purple flowers is crosse with a plant that is true - breeding for smooth green pods. d. a plant that is true - breeding for green pods is crossed with a pla that is heterozygous for green pods.

Explanation:

To determine if two traits are distributed independently (Mendel's law of independent assortment), a dihybrid cross is needed. A dihybrid cross involves two different traits.

• Option A: Involves two traits (seed shape - wrinkled/round and seed color - yellow/green). True - breeding parents (homozygous) will produce \(F_1\) hybrids. The \(F_2\) generation (if \(F_1\) is self - crossed) can show if the traits assort independently (expected 9:3:3:1 ratio if independent).
• Option B: Only one trait (flower position - axial/white is not a valid pair for dihybrid; should be two different traits like flower position and color).
• Option C: Traits (flower position and pod texture/color) - but not clear if they are the right combination for a standard dihybrid to test independent assortment as described in classic Mendelian experiments.
• Option D: Only one trait (pod color - green, and a cross between homozygous and heterozygous for the same trait, not two different traits).

Answer:

A. A plant that is true - breeding for wrinkled yellow seeds is crossed with a plant that is true - breeding for round green seeds.