<prompt> Bheka isigaba esingezansi bese uphendula umbuzo emva kwalokho ngolimi olufanayo nesigaba: Ukudlula: I-xylem iyisicubu esiyinkimbinkimbi semithambo esakhiwa ama-tracheids noma izakhi zemithambo ezihambisa amanzi, kanye nemicu namaseli e-parenchyma. Ama-tracheids angamangqamuzana amade ane-lignified secondary thickening of the cell walls, akhethekile ekuhambeni kwamanzi, futhi aqala ukuvela ezitshalweni ngesikhathi sokudlulela kwazo ezweni esikhathini se-Silurian eminyakeni engaphezu kwezigidi ezingama-425 edlule bheka i-Cooksonia. Ukuba ne-xylem tracheids kuchaza izitshalo ezinemithambo yegazi noma i-Tracheophytes. Ama - tracheid ayizinhlayiya ze - xylem ezicijile, ezinde, ezilula kunazo zonke ezinezindonga eziqhubekayo zamangqamuzana okuqala kanye nokuqiniswa kodonga lwesibili olwenziwe ngamangqamuzana ngesimo sezindandatho, ama - hoops, noma amanethiwekhi e - reticulate. Ama-tracheids anzima kakhulu anezimbobo ezifana nama-valve ezibizwa ngokuthi ama-pit anezinhlangothi eziphawuleka kuma-gymnosperm. Ama - fern namanye ama - pteridophyte nama - gymnosperm ane - xylem tracheids kuphela, kuyilapho izitshalo eziqhakazayo nazo zine - xylem vessels. Izakhi ze-vessel zingamaseli e-xylem angenalutho ngaphandle kwezindonga eziphethu eziqondiswe ekugcineni ukuze kwakheke amashubhu amade aqhubekayo. Ama - bryophytes awanalo ithishu le - xylem yangempela, kodwa ama - sporophytes awo anethishu eqondisa amanzi eyaziwa ngokuthi i - hydrome eyakhiwe ngamangqamuzana amade akhiwe ngendlela elula. Umbuzo: Hlobo luni lwezitshalo ezine-xylem?  <response>: Ama-tracheophytes 