Figure 5.

Percentage frequency of rDNA sites along the chromosome arm in the most sampled families of angiosperms (a) and gymnosperms (b). The sites were positioned in one of four equal-sized regions of the arm or spanning the whole arm. p, proximal; ip, interstitial-proximal; it, interstitial-terminal; t, terminal; wa, whole arm. The number of karyotypes analyzed in each family appears in brackets.