Practice question

Shoot tip culture qualifies as organ culture because explant retains organized structure of shoot apical meristem plus one to three leaf primordia and continues organized growth maintaining polarity and tissue layer arrangement tunica corpus. Unlike callus culture where organization is lost into unorganized parenchyma, or cell suspension where aggregates disperse in liquid agitation, or protoplast culture where wall removed exposing naked membrane, shoot tip preserves defined zonation central zone peripheral zone rib meristem and procambium differentiation pathway. Culture on hormone balanced medium supports leaf expansion and internode elongation converting tip into miniature shoot that can be rooted. Since meristem remains intact, organ culture ensures high genetic stability avoiding mutation accumulation common in callus phase. Practical uses range from micropropagation of horticultural species to germplasm conservation under slow growth minimal medium and virus elimination when larger meristem is needed for survival in recalcitrant species where 0.1 mm meristem excision suffers low regeneration. Thus shoot tip culture bridges meristem culture and nodal culture methods for commercial clonal production.