Biology · Oct / Nov 2023 · Paper 42 · Question 2
0610
As printed in the paper
The question as text
Fig. 2.1 is a photograph of some leaves of a water lily, which is a hydrophyte. The water lily has adaptive features that are found in many different hydrophytes. Fig. 2.1
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2(a)[2]
an inherited (structural) feature ;
that helps an organism to, survive / reproduce (in its environment) ;
2(b)(i)[3]
A – palisade mesophyll ;
B – spongy mesophyll ;
C – air spaces ;
2(b)(ii)[3]
any three from:
many (air spaces) / large (air spaces) ;
reduces density (of the leaf) ;
allowing it to float / be on water / be near surface of water ;
(so) accessible, to light / carbon dioxide / gas exchange / AW, for photosynthesis ;
2(c)(i)[5]
total of five from:
comparison - max three from:
1
tomato has more stomata on its lower epidermis than its upper epidermis ;
2
water lily has, stomata only on upper epidermis / no stomata on lower epidermis ;
3
water lily has more stomata on upper epidermis than tomato ; ORA 4
water lily has more stomata (per mm2) than tomato ; ORA
5
any use of comparative manipulated figures from table including unit (at least once in the answer) ;
explanation:
6
(tomato has most stomata on lower epidermis) so not facing the sun ; 7
idea that tomato needs to reduce, water
loss / transpiration / evaporation ;
8
water lily (floats on water so) only upper surface is exposed to air ; 9
(water lily has large number of stomata) as water does not need to be conserved ;
2(c)(ii)[1]
guard (cells) ;
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