Q.Which of the following explains how progeny can possess the combinations of traits that none of the parents possessed?

Step 1. In a dihybrid cross such as round-yellow x wrinkled-green peas, the F2 generation includes not just the two original parental combinations but also two new recombinant classes - round-green and wrinkled-yellow - that neither parent possessed.

Step 2. This happens because the two gene pairs (for seed shape and cotyledon colour) are located on separate chromosomes and segregate into gametes independently of each other, so all four possible allele combinations (RY, Ry, rY, ry) form in the F1 dihybrid's gametes, not just the two parental combinations. …

Link the appearance of new recombinant phenotype classes in F2 to independent …

• Confusing the Law of Segregation (about one gene's two alleles) with the Law of Independent Assortment (about two different genes). …