Parental & recombinant genotypes in a dihybrid cross

    A crossover between two loci reverses the phase (i.e., changes cis to trans or v.v.) of the linked alleles. For example, given the cis arrangement of the A & B alleles (top left), recombination between the 2nd and 3rd chromatids produces recombinant Ab and aB trans gametes.

Figure ©2002 by Griffiths et al.; all text material ©2008 by Steven M. Carr