Final answer:
The expected number of double-crossovers between st and e can be calculated by multiplying the recombination frequencies between st and other genes in the linear map. However, without the specific recombination frequency between st and e, we cannot calculate the exact expected number.
Step-by-step explanation:
The expected number of double-crossovers between st and e can be calculated by multiplying the recombination frequencies between st and other genes in the linear map.
Since the recombination frequency between st and the other genes in the map is not provided, we cannot calculate the exact expected number of double-crossovers. However, we can say that if the genes st and e are closer together on the chromosome, the recombination frequency between them would be lower, resulting in a lower expected number of double-crossovers.
On the other hand, if the genes st and e are farther apart, the recombination frequency between them would be higher, leading to a higher expected number of double-crossovers.