10 Transpiration, transport and support in plants I
2nd Term WS 10
(a) (208–93) / 93 × 100% 1m
= 124% 1m
(b) This can reduce transpiration. 1m
The stomata on the lower surfaces are sheltered from air current / heat. 1m
(c) Increase the sample size for the shade leaves.
/ Measure the thickness of cuticle.
/ Record the size of leaves. / Record the size of stomata. / Record the number of stomata.
/ Measure the light intensity to classify the types of leaves.
/ Repeat the experiment using other plants of the same species. (any 2) 1m x 2
(a) transpiration 1m
(b) Photosynthesis is essential for plants to gain energy.
/ Gas exchange is needed for photosynthesis to occur.
/ Plants need to open stomata to exchange gases.
/ Some water is lost through the cuticle. (any 2) 1m x 2
1m x 2
(b) Stoma allows gases to pass in and out of the leaf. 1m
Cuticle reduces water loss from the leaf surface. 1m
(c) (i) A floating plant 1m
(ii) The leaf has stomata and cuticle on the upper epidermis. 1m
A leaf from a submerged plant has no stomata and cuticle on both the upper and
lower epidermis. 1m
(a) Bubble potometer
(b) (25 – 1) / 30
0.8 mm/min 1m
(c) It is used to reset the position of the air bubble.
(d) I: light intensity 1m
II: relative humidity 1m