Practice question

Root system zonation comprises protective root cap covering meristematic zone with dividing initials, rapid elongation zone where cells undergo extensive vacuolar expansion increasing length dramatically, and maturation zone where differentiation completes and specialized cells emerge. Root hairs, tubular tip-growing extensions of specialized trichoblast epidermal cells, arise exclusively in maturation zone after cessation of elongation ensuring stable anchorage and efficient water and mineral nutrient absorption. Specification depends on positional signaling from underlying cortex, transcriptional cascade involving WER, GL3/EGL3, GL2, RHD6, and RSL4 dictating hair versus non-hair epidermal fate decisions.