Question

(a) A student investigates the effect of temperature on the rate of transpiration.
Fig. 7.1 shows the apparatus used.

The student measures the distance the air bubble moves in 22 minutes.
The distance the air bubble moves is used to calculate the rate of transpiration.
The experiment is repeated at three different temperatures.
Table 7.1 shows the results.

(i) Calculate the rate of transpiration at 10°C.
Give your answer to 1 significant figure.

………………………………………………………………………………………………………. mm/min 

(ii) State one other factor that affects the rate of transpiration.

(iii) Define the term transpiration.

(b) Fig. 7.2 shows the initial pathway of water through a plant.

(i) State the names of the cells labelled X and Y in Fig. 7.2.

X …………………………………………………………………………
Y …………………………………………………………………………
(ii) State the name of the process that causes absorption of water into the plant cells.

▶️Answer/Explanation

Ans : 7(a)(i) (7 / 22=) 0.318 ;
0.3 (mm / min) ;

7(a)(ii) humidity / AVP ; 
7(a)(iii) any three from: water evaporates from (surfaces of) mesophyll cells ;
lost as water vapour (from plant leaves);
through the stomata ;
by diffusion ;

7(b)(i) X – root hair (cell) ;
Y – root cortex (cell) ;

7(b)(ii) osmosis ;