<prompt> Bheka isigaba esingezansi bese uphendula umbuzo emva kwalokho ngolimi olufanayo nesigaba: Ukudlula: I-phloem iyisicubu esikhethekile sokuthuthwa kokudla ezitshalweni eziphakeme, ngokuyinhloko sithutha i-sucrose emithambekeni yengcindezi ekhiqizwa yi-osmosis, inqubo ebizwa ngokuthi i-translocation. I-phloem iyisicubu esiyinkimbinkimbi, esiqukethe izinhlobo ezimbili eziyinhloko zamangqamuzana, ama-sieve tubes namangqamuzana ahlobene eduze, kanye namangqamuzana e-parenchyma, imicu ye-phloem nama-sclereids. Amapayipi okuhlunga ahlanganiswe ekugcineni-kuya-ekupheleni ngamapuleti wokugcina agqokwa phakathi kwaziwa njengamapuleti okuhlunga, avumela ukuthuthwa kwe-photosynthate phakathi kwezakhi zokuhlunga. Izakhi ze - sieve tube azinawo ama - nucleus nama - ribosome, futhi umzimba wazo nemisebenzi yazo kulawulwa amangqamuzana ahambisana nawo ane - nucleate. Amangqamuzana ahambisana nawo, axhunywe kumashubhu okuhlunga nge - plasmodesmata, anomthwalo wokulayisha i - phloem ngoshukela. Ama - bryophyte awanayo i - phloem, kodwa ama - moss sporophyte anesikhumba esilula esinomsebenzi ofanayo owaziwa ngokuthi i - leptome. Umbuzo: Iyini i - leptome?  <response>: izicubu ezilula ezinomsebenzi ofanayo 