Question

gregor mendel used pea plants that were heterozygous for each of two traits—seed color and seed shape—to generate a dihybrid cross. the phenotypic ratio of the resulting offspring was nine with round and yellow seeds, three with round and green seeds, three with wrinkled and yellow seeds, and one with wrinkled and green seeds. from these results, what could mendel conclude?
○ traits are inherited as pairs, sets, or groups.
○ traits that are dominant mask traits that are recessive.
○ gametes carry one allele for each trait.
○ traits are passed independently of one another.

Explanation:

1. Analyze the dihybrid cross results (9:3:3:1 ratio for round - yellow, round - green, wrinkled - yellow, wrinkled - green).
2. Recall Mendel's laws: The Law of Independent Assortment states that alleles of different genes assort independently during gamete formation. In the dihybrid cross, the inheritance of seed color and seed shape traits shows that they are passed independently.
3. Evaluate other options:

• "Traits are inherited as pairs, sets, or groups" is incorrect as the ratio shows independent inheritance, not linked inheritance as groups.
• "Traits that are dominant mask traits that are recessive" is related to the Law of Dominance, but the dihybrid cross result here is more about independent assortment than just dominance masking.
• "Gametes carry one allele for each trait" is related to the Law of Segregation, while the dihybrid cross result is about the independent assortment of different traits.

Answer:

D. Traits are passed independently of one another.