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.