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Unformatted text preview: CAMBRIDGE INTERNATIONAL EXAMINATIONS NOVEMBER 2002 iary Level GCE Advanced Subs E
U ons Syndicate mati Local Exam —Syllabus —Pa
— AS Level Examinations — November 2002 9700 m Expected Answers ' m Additional Guidance I 10 10
20 0 CM > 50 mm 0.75M & 1M < 50 mm change in length calculated correctly mean calculated correctly _ + and — signs used correctly - signs must be used axis correctly orientated with units and scale correct
all plots correct ' ’
straight line of best ﬁt correct water potential of distilled water > than cells Accept hypo and
therefore water enters cells hypertonic if correct but
water potential of 1M < cells max 4 if no correct ref to
therefore water leaves cells water potential correct ref to water potential correct as read from graph with units mol dm‘°’
reason must indicate net movement/ equilibrium more accurate
good reason eg can measure to several decimal
places / length may be cut at angle Any good reason but reject
can work out mass / vol of
Explain how epidermal strips obtained
~ - immerse in soln for > 15 mins
Place under microscope
Determine percentage plasmolysis for each solution '
Use 50+ cells each‘tirne;
, Plot graph
Determine 50% plasmolysis
Plasmolysis explained I incipient plasmolysis ...
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This note was uploaded on 01/25/2012 for the course BIO alevels taught by Professor J.b during the Spring '11 term at Taylor's.
- Spring '11