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:

Mendel's dihybrid cross showed that different traits (seed color and shape) are inherited independently. The phenotypic ratio (9:3:3:1) indicates that alleles for different traits assort independently during gamete formation. This is Mendel's law of independent assortment.

• The first option is incorrect as Mendel's work showed independent inheritance, not inheritance as groups.
• The second option (dominant - recessive masking) is related to monohybrid crosses (e.g., single - trait crosses like pea height) and not the key conclusion from dihybrid crosses.
• The third option about gametes carrying one allele per trait is related to Mendel's law of segregation (monohybrid cross concept), not the dihybrid cross conclusion.

Answer:

Traits are passed independently of one another.