Page 247 - SUBSEC October 2017_Neat

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02207032/CAPE/SPEC/KMS 2017

CAPE BIOLOGY

UNIT 2 -- PAPER 032

MARK SCHEME

UK XS
Question 1.

(a) Specimen A: slide of lower epidermis of a leaf (whole mount)

 Clear accurate line representation of specimen
 Clean continuous lines of even thickness

 Use of label lines that do not cross

 Accurate labelling
 Features correctly proportioned
 Magnification given
 Title given

Any point -- 1 mark 6

(b) (i) Specimen B: dicotyledonous lead

 Mean correctly calculated 2
 Calculation of stomatal density 3
 Use of appropriate units 1

(ii)  No 1
 Dicotyledonous leaf 1

(c)  Leaf rolled - to reduce transpiration rate
 Stomata on lower epidermis not exposed to dry atmosphere
 Presence of hairs trap H 2 O -- creating humid environment

 Humid conditions in interior result in reduced
transpiration.
 Thick cuticle to reduce water loss across epidermis

Any point -- 1 mark up to a maximum of 4 marks
4

6 12