Fig. 1. Views of maize root quiescent center (QC). (A) Autoradiograph of a median longitudinal section (MLS) of a maize root supplied with [³H]thymidine for 8 hours. Note prominent QC and root cap (RC). (B) MLS showing QC and RC detached together from root proper. (C) Whole maize root with QC and RC dissected free of the root proper. (D) MLS showing detached QC; the RC has already been excised. The extent of the proximal meristem (PM) is also shown. Scale bar, 100 µm.