I've seen many textbook images of alleles on homologous chromosomes with the gene loci identified but how could this be visualised on linear DNA sequences with the bases written out? Is it that you would have one DNA strand with its nucleotides and then another adjacent DNA strand with nucleotides at the same locus but different in sequence? Any visual representations would be helpful
Edit: This picture below shows how alleles can be seen on the chromosomes but it's not clear about where the change in sequence would be on the nucleotide bases. The typical diagrams show the homologous pairs but they don't usually show the change of base sequences on a small scale.