Question

what factor determines how often two alleles for linked genes will recombine?
the length of the dna sequences corresponding to the genes
the physical distance that separates them on the chromosome
whether the alleles are dominant or recessive
the size of the chromosome on which they are located

Explanation:

The frequency of recombination of linked - genes is determined by the physical distance between them on the chromosome. The farther apart two genes are on a chromosome, the more likely they are to recombine during meiosis due to crossing - over events. The length of DNA sequences, dominance or recessiveness of alleles, and chromosome size do not directly determine the recombination frequency of linked genes.

Answer:

B. The physical distance that separates them on the chromosome