adaptations of plants for exchanging materialsWatch
Are you doing GCSE or A level ("single science" suggests GCSE)
All you need to know (and which you can actually work out cos God (if you believe in him/her - sorry but I don't!) was not stupid i.e. everything in nature exists/occurs for a logical reason, is as follows:-
1. Large surface area(s):
--- a) Roots branch thousands of times (for e.g. a large oak) especially adventitious roots as in dicotyledonous plants (less so in e.g. carrots with a tap root). They have millions of minute root hairs, which are long and thin (+ unicellular) so extremely large surface area.
--- b) Leaves are numerous (hundreds of thousands in our e.g. above [oak tree]), flat broad shape, so again v v large surface area.
Happy so far?? Yes I can see a smile on your face already -a.a.a.- be careful with that bite of sausage - you don't want to end up with a sore tongue !! . Enjoy your breaky!
2. Look up stomata and guard cells and how a stoma opens and closes with changing levels of e.g. CO2. Again millions of stomata.
3. DAYTIME: more CO2 going in O2 out of leaves (photosynthesis taking place) - conc-n gradients favourable for exchange (look up diffusion). NIGHTTIME: opposite.
4. Very small/thin distance for gases (in leaves) and water/minerals (in roots) to diffuse across e.g. single cell wall plus cell membrane in root hairs, so transport faster, yeah?
RATE OF DIFFUSION is proportional to:
SURFACE AREA X CONC. GRADIENT
FROM THIS EQUATION you can predict ALL the above points - think, think, think - don't just try to cram things into your brain as teachers try to make you do - work things out and not only will you remember them for decades, BUT it will also be FUN AND COOL!