Final answer:
The probability of double-recombinant progeny given single recombination frequencies of 15% and 20% is 3%. In a dihybrid cross, the highest predicted frequency for recombinant offspring between unlinked traits is 50%, not 60%, because each combination of parental and nonparental types can only account for a maximum of 50% of the progeny.
Step-by-step explanation:
The subject of this question is Biology, specifically genetics and the calculation of recombination frequencies. The probability of double-recombinant progeny is the product of the single recombination frequencies. Therefore, if the single recombination frequencies of progeny are 15% (0.15) and 20% (0.20), then the probability of double-recombinant progeny would be:
0.15 × 0.20 = 0.03 or 3%
However, in the case of recombinant frequency in a dihybrid cross, it is important to note that the highest frequency observed for recombinant offspring between unlinked traits is 50%, and not 60%. This is because each parental allele combination has a 25% chance and is then added together for recombinant types, which cannot exceed 50%. Genes that are very far apart on the same chromosome or on different chromosomes assort independently, making the recombination frequency approach 50%.