slantcellorganisation
waxtuticle
goooooooooooooooop rooons
Upperepidermis
Pali
sidemesophyll
xylem water
Phloem good
o
spongymesophyll
o s epidermaltissue
airspaces
stomata guardcell
Theupperepidermisarecoveredwith a
waxycuticlewhichhelpstoreducewaterlossbyevaporation
heupperepidermis istransparent sothatlightcanpassthroughit tothepalisidelayer
hepalisidelayercontainslotsofchloroplasts forphotosynthesis Thismeansthattheyare nearthetopof the
leafwheretheycangetthe mostlight
hexylemandphloemformanetworkofvascularwhichtransportwaterandmineralsandhelpsupportthe
structure
hespongymesophyllcontainslotsofairspacesandalargesurfaceareaforgasexchange
helowerepidermiscontains guardcellswhichopenandclosestomata to preventwaterloss
Stomata are gaps inthe lowerepidermis whichallowgasexchange
, ranslocation
Phloemtubestransportfood
d
Made
of columnsofelongatedlivingcellswithsmallpores in theendwalls to
ÉPÉE
Wow a sap to flowthrough
ygg.gg
heytransportfoodsubstances mainly dissolvedsugars made inthe leaves
to therestoftheplantforimmediateuse orforstorage
The transport directions This process is calledtranslocation
goes inboth
Xylemtubes takewaterup
Made deadcellsJoinedend to endwith noendwallsand aholedown
y of
themiddle They'restrengthened withlignin
They carry waterandmineral ions fromtheroots to thestem and
leaves
Themovementof waterfromtheroots through thexylemand out of theleaves is called
the transpiration stream
ranspirationisthe
loss ofwaterfromtheplant
1 Transpiration iscausedbyevaporation anddiffusion
Itamar 2 This evaporationcreates a slightshortage of
i
water in theleaf so morewater is drown up
fromtherestoftheplantthroughthexylemvessies
This meansmorewater isdrawn
upfrom theroots
and so there's a constanttranspiration stream of
water