Q.State Mendel's Law of Independent Assortment. Illustrate it with reference to Mendel's dihybrid cross between a pea plant with round, yellow seeds ($RRYY$) and one with wrinkled, green seeds ($rryy$), stating the genotype and phenotype of the F1 generation.

Step 1. The Law of Independent Assortment states that when two different gene pairs are considered together, the segregation of one gene pair's alleles into gametes is independent of the segregation of the other gene pair's alleles, so all combinations of alleles appear among the gametes with equal frequency.

Step 2. Parents: RRYY (round, yellow) × rryy (wrinkled, green). Gametes: RY only, and ry only.

Step 3. Every F1 offspring receives one R, one Y (from the round-yellow parent) and one r, one y (from the wrinkled-green parent), giving genotype RrYy.

Step 4. By the Law of Dominance applied to each gene separately, R (round) dominates r, and Y (yellow) dominates y, so every RrYy F1 plant is phenotypically round and yellow.

State the law, then apply it to derive the F1 genotype/phenotype from the doubly homozygous parental cross, each gene considered via the Law of Dominance.

• Confusing this law with the Law of Segregation (segregation concerns ONE gene's two alleles; independent assortment concerns how TWO DIFFERENT genes' alleles combine).
• Forgetting to specify BOTH the F1 genotype and phenotype.