Biology · Oct / Nov 2022 · Paper 41 · Question 3

transpiration ;

ensure continuous column of water / prevents air bubbles / prevents airlock ;

prevent, evaporation / condensation (from the top of the burette, affecting the volume of water in the burette) / AW ;

measure the decrease in the volume of water (in burette over a period of time) / record the decrease in mass (over time) ;

12 096 g (per m2) / 12.096 kg (per m2) ;;;

any five from:

1

as temperature increases, (rate of) water loss increases ; 2

ref to steeper rate / greater loss of water, after 37 / 38 oC ; 3

any correct comparative data quote (with units at least once) ;

4

water vapour lost, through stomata / between guard cells ; 5

evaporation from mesophyll into air spaces ;

6

(diffusion) down a, water potential, gradient ;

7

increasing temperature increases kinetic energy (of water molecule) ;

8

faster (rate of) more, diffusion ;

9

stomata open wider / more stomata open in high(er) temperatures ;

10 AVP ;

no diffusion (of water vapour) ;

(because) no water potential gradient / described ;

(it has a) continuous supply of water / AW ;

line drawn below original line ;