Page 171 - SUBSEC October 2017_Neat

- 3 -
02107032/CAPE/SPEC/KMS 2017

BIOLOGY

UNIT 1 -- PAPER 032
MARK SCHEME

Question 1. (continued) UK XS

(c) (i) Diagrams to show how the cucumber strips would look after
30 minutes.

0.1M -- emphasis on cortical parenchyma

Cells splitting -- 1 mark 2
Correct line representation -- 1 mark

(ii) 0.5M -- emphasis on cuticularized epidermis

Carving outwards -- 1 mark
Correct line representation -- 1 mark 2

(d) (i)  The 0.1M solution has a higher water potential than
the cell sap of the cortical cells of the strip.
 The water from the solution passes into the cells by
osmosis. 2
 The cortical cells expand with turgidity.
 Their increased size causes the inelastic epidermis
to be curved back.

3 correct points -- 2 marks
2 correct points -- 1 mark
1 correct point -- 0 marks