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5090 s12 ms 61 .pdf


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UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
GCE Ordinary Level

MARK SCHEME for the May/June 2012 question paper
for the guidance of teachers

5090 BIOLOGY
5090/61

Paper 6 (Alternative to Practical), maximum raw mark 40

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of
the examination. It shows the basis on which Examiners were instructed to award marks. It does not
indicate the details of the discussions that took place at an Examiners’ meeting before marking began,
which would have considered the acceptability of alternative answers.
Mark schemes must be read in conjunction with the question papers and the report on the
examination.

• Cambridge will not enter into discussions or correspondence in connection with these mark schemes.

Cambridge is publishing the mark schemes for the May/June 2012 question papers for most IGCSE,
GCE Advanced Level and Advanced Subsidiary Level syllabuses and some Ordinary Level
syllabuses.

Page 2
1

(a)

Mark Scheme: Teachers’ version
GCE O LEVEL – May/June 2012

Syllabus
5090

volume of dough / cm3
A
B
Initial
20
20
Final
51
34
Change
31
14

(b) (i) volume / height (increases) more in A than B ;
more bubbles / gas in A / bubbles /gas evenly distributed in A or converse ;
(ii) respiration / respiring ;
aerobic / anaerobic ;
carbon dioxide (CO2) given off ;
(idea of) trapped in dough increasing volume AW ;
(c) 2 or more samples (of A) used / AW ;
same start volumes / amounts / height of dough used ;
at range of temperatures / different temps ;
suitable temperatures identified ;
left for same length of time ;
change (in volume) measured / compared AW ;
repeat / replicate / calculate the mean ;
AVP ;

Paper
61

[3]

[2 max]

[3 max]

[5 max]
[Total: 13]

2

(a) Drawing
five leaflets drawn ;
clean lines, good proportions, at least 7cm length ;
midrib + veins well drawn on at least one ;
serrated margin drawn as a continuous line on one ;
Labels
lamina / blade / margin ;
midrib / veins ;
petiole / leaf stalk ;
(b) photosynthesis:
(green) chlorophyll + ref to light (absorption) ;
large surface area + ref. to light or gases ;
attached to stem / veins / midrib + transport of correctly named materials ;
leaf thin + fast diffusion / light penetration / gaseous exchange ;
(c) (i) reference to leaf closing over insect / leaf margins forming trap AW ;

[4 max]

[L2 max]

[3 max]
[1]

(ii) nitrate / (named) nitrogen-containing compound / phosphate ;

[1]

(iii) enzymes / proteins / nucleic acids / DNA / cell membrane / chlorophyll / ATP ;

[1]
[Total:12]

© University of Cambridge International Examinations 2012

Page 3
3

Mark Scheme: Teachers’ version
GCE O LEVEL – May/June 2012

Syllabus
5090

(a) (i) stamen / anther / pollen sac correctly indicated and named ;
(ii) stigma correctly identified and named ;

Paper
61
[1]
[1]

(b) tissue prepared or sample taken ;
Benedicts added ;
heated / warmed ;
colour changes described ;
use of water bath or another safety feature ;
(c) (i) time in hours
0.0
2.0
4.0
6.0
8.0
10.0

length / mm
(0)
18–20
23–25
28–30
34–36
41–43

[5]

[2]

(ii) time on x axis, length on y ;
grid fully used and axes fully labelled with linear scales ;
plotting correct ;
good, neat line of best fit drawn ;

[4]

(iii) growth (rate) faster (at first) becoming constant / AW ;

[1]

(d) towards chemical / hormone (in ovule) ;

[1]
[Total: 15]
[Paper total: 40]

© University of Cambridge International Examinations 2012


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