Practice question

Histologically shoot apical meristem contains central zone harboring large vacuolated slowly dividing pluripotent stem cells, peripheral zone comprising smaller rapidly dividing cells recruited into leaf or flower primordia, and rib meristem generating pith and vasculature. Central zone divisions predominantly anticlinal at low frequency preserving reservoir while displacing daughters peripherally toward organogenic zones. Signals from organizing center WUS maintain CZ fate, auxin maxima via PIN1 polarity initiate organs in PZ, and CLV feedback restricts overall size, ensuring balanced self-renewal versus lateral organ production sustaining indeterminate growth characteristic of flowering plants.