Final answer:
The recombinant offspring are the ones with 80 individuals each, with genotypes yybb and yybb, showing new combinations of traits not found in either parent in the initial cross.
Step-by-step explanation:
The recombinant offspring from the cross in question are the yybb and yybb with 80 individuals each. The other two groups with 420 individuals each are the parental types.
In genetics, recombinant offspring result from a process where the parental DNA sequences are mixed during gamete formation, resulting in a new combination of traits that were not found together in either parent. The situation described suggests a dihybrid cross where the F1 generation, which are heterozygous for both traits, was crossed with a homozygous recessive individual (aabb).
The parental offspring, which represent the original parental genotypes, occur more frequently and in this case, are indicated by the larger number of yybb and yybb individuals. The recombinant offspring, which display new combinations of traits, typically occur less frequently and thus are represented by the two groups with 80 individuals each.