BIO - 2g. + 2h. gas exchange and respiration in plants

during photosynthesis is there a higher conc. of O₂ inside or outside of the leaf

inside

during respiration is there a higher or lower conc. of CO₂ inside or outside the leaf

inside

leaf adaptation for gas exchange: spongy mesophyll and air spaces

large air spaces allow gases to circulate and large SA of spongy cells allows for efficient gas exchange

leaf adaptation for stomata and guard cells

underside contains all/most

during the day guard cells open stomata to allow CO₂ in for photosynthesis and during the night they are closed to reduced water loss

what are guard cells when stomata are open

turgid, lots of water exiting through them

what are guard cells when stomata are closed

flaccid, deflate as there is no water

gas exchange

the swapping of gases

during the day what occurs at a higher rate and why

photosynthesise as there is a high light intensity meaning more O₂ leaves the cell and more CO₂ is absorbed

state the colour of hydrogen-carbonate indicator high - low conc

high - yellow

atmospheric air - orange

less - red

low - purple

what do you need for the hydrogen-carbonate