Fig. 9. Some of the tetrad types predicted after sporulation of a diploid
strain resulting from the cross *AB* x *ab*, where *A *and
*B* are on different chromosomes. Note that parental ditypes and nonparental
ditypes should occur with equal frequency. If at least one of *A* and
*B* is sufficiently far from its centromere to behave as if unlinked
to its centromere, then 4 different tetratypes can be generated, each with
a frequency equal to that of the parental and nonparental ditypes. Two of
the possible tetratypes are shown in the figure.