Gas Exchange in Plants
SBI 3U
Plants need Oxygen too.
• Plants obtain the
gases they need
through their leaves.
• They require oxygen
for respiration and
carbon dioxide for
photosynthesis.
http://www.chemsoc.org/networks/LearnNet/cfb/images/12A.jpg
The Epidermis of a leaf.
The gases diffuse into the
intercellular spaces of the
leaf through pores, which
are normally on the
underside of the leaf –
stomata. From these
spaces they will diffuse
into the cells that require
them.
Stomatal opening and closing depends on changes in
the turgor of the guard cells. When water flows into the
guard cells by osmosis, their turgor increases and they
expand. If the guard cells loose water the opposite
happens and the pore closes.
http://virtual.yosemite.cc.ca.us/randerson/Lynn's%20Bioslides/27.jpg
http://biology.unlv.edu/Schulte/Anatomy/Leaves/PopulusStomata.jpg
http://www.plantsci.cam.ac.uk/Webb/images/stomata.jpg
http://bio1151.nicerweb.com/Locked/me
dia/ch36/36_15GuardCellFunction.jpg
http://www.progressivegardens.com/knowledge_tree/stomata.jpg
Lenticels – pores in the bark of
stems
http://sciencecity.oupchina.com.hk/biology/student/glossary/img/l
enticels.jpg
http://www.treedictionary.com/DICT200
3/IMAGES/LENTICELS%20BIRCH.jpg
http://www.biotopics.co.uk/plants/leafst.html
http://www.digitalfrog.com/resources/archives/leaf.jpg
http://home.comcast.net/~john.kimball1/BiologyPages/S/stoma.gif
http://www.northern.edu/ramsayj/etechWeb/images/leaves/leaf%20example1%20copy.JPG
Transport in plants
SBI 3U
http://www.bbc.co.uk/schools/gcsebitesize/img/bixylemphloem.gif