Fig. 1
The phenomenon of recombination. (a) A diploid cell has two chromosomes with two genetic loci A and B, with two alleles of each (A or a and B or b). (b) Chromosomes after replication and cell division might inherit A and B in the same combinations as in the diploid progenitor. (c) The two gene alleles can also reassort by recombination so that the chromosomes have allele combinations that were not present in the original diploid cell (A b and a B) (After Stahl 1979)