Final answer:
During the migration of a Holliday junction in genetic recombination, all products are heteroduplex in that region, indicating the pairing of DNA strands from different molecules.
Step-by-step explanation:
All products, regardless of cleavage, are heteroduplex in the region of Holliday junction migration. A Holliday junction is an intermediate structure formed during the process of genetic recombination, which is an important mechanism for generating genetic diversity. During the migration of the Holliday junction, the strands of DNA from the recombining DNA molecules are cleaved and exchanged, and this results in regions where the DNA from one molecule is paired with the DNA from another molecule, creating a heteroduplex. These heteroduplex regions contain mismatched nucleotides that can be repaired later, leading to gene conversion or the generation of new genetic combinations.