Problem: Heterozygous individuals have two different alleles at the same locus. These alleles could be having different base pair lengths. When this is treated with restriction enzymes for Southern blot probe, two different bands will be produced in each lane due to difference in their lengths. Homozygous individuals, on the other hand, have two copies of the same allele at a particular gene locus. The fragments are of equal lengths and will show a single band in each lane. Need Assignment Help?