0610_w12_ms_61x MS61 0610 W12 Ms 61
User Manual: MS61
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CAMBRIDGE INTERNATIONAL EXAMINATIONS
International General Certificate of Secondary Education
MARK SCHEME for the October/November 2012 series
0610 BIOLOGY
0610/61 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 should be read in conjunction with the question paper and the Principal Examiner
Report for Teachers.
Cambridge will not enter into discussions about these mark schemes.
Cambridge is publishing the mark schemes for the October/November 2012 series for most IGCSE,
GCE Advanced Level and Advanced Subsidiary Level components and some Ordinary Level
components.
www.XtremePapers.com
Page 2 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0610 61
© Cambridge International Examinations 2012
Question Mark scheme Mark
allocation
Guidance
1 (a) (i) respiration / fermentation; [1]
(ii) carbon dioxide; [1] A chemical formula if correct.
(iii) limewater;
cloudy / milky / AW;
[2]
A ecf If test matches gas named in (ii)
(b) temperature control / avoid temperature fluctuation / to
keep them at same temperature / AW;
(warm water) increase in rate of reaction / activates yeast /
increases respiration / AW;
correct reference to enzyme activity;
Max [2]
(c) Description
W1 lower number bubbles than W2 / AW;
No: bubbles decrease from trial 1 to trial 2 and /or trial 3
(for W1 and /or W2 / AW;
Explanation
less yeast in W1 / W2 has been (reacting) in warm water
longer / AW;
sugar / substrate decreasing;
Max [3] Explanation must link to correct description
Page 3 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0610 61
© Cambridge International Examinations 2012
(d) Any 2 sources of error and 2 linked suggestions of
improvement.
e.g.
Error: change in temperature / different starting
temperatures / different length of time in warm water;
Improvement: (monitor with thermometer and) add hot /
cold water (to keep constant) / use water bath / start
testing at same time / AW;
Error: varying amounts of yeast
Improvement: use same mass yeast / AW;
Error: (inaccurate) timing;
Improvement: use stop watch / AW;
Error: (variable) shaking of tube;
Improvement: shake for same amount of time / at same
rate / AW;
Error: inaccurate counting of bubbles / different sized
bubbles;
Improvement: use gas syringe / measuring cylinder /
repeat (experiment);
Max [4]
NB Improvement should be specific to an error and refer to
an experimental method.
[Total: 13]
2 (a) O outline;
S size and proportion;
D details;
Label;
[4]
Page 4 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0610 61
© Cambridge International Examinations 2012
(b) (i) midrib / (network of )veins / petiole or leaf stalk / serrated
edge / AW / AVP
[1] Ig size / shape /sharp.
Give ECF BOD for incorrect drawing label.
(ii) entire v divided (into leaflets) / simple v compound / AW;
leaf v leaflets;
pointed tip v rounded tip;
AVP;
Max [2] Must have a comparative answer.
(c) (i) line to or within palisade cell; [1]
(ii)
start / entry from outside through lower stoma;
end on or in labelled cell / c(i) cell;
[2] Max 1 if no arrows or arrows in wrong direction
(d) measurement : 14 ± 1 mm);
formula : length ÷ magnification;
calculation : 0.05 ( 0.046 – 0.054 mm);
[3]
If different unit e.g. cm, then units must be present.
(e) (i) idea of mesophyll cells / blade / lamina / AW decomposed
first / veins or midrib remain;
midrib / veins harder or tougher (so remain) / lamina softer
or weaker / AW;
by bacteria / fungi / microorganisms
or detritivores / named examples;
digestion / respiration / decay (by decomposers);
AVP;
Max [3]
Page 5 Mark Scheme Syllabus Paper
IGCSE – October/November 2012 0610 61
© Cambridge International Examinations 2012
(ii) A –axes and linear scaling;
S – size;
P – correct plots;
L – line;
[4]
(iii) increase in mass at start / first 6 months / AW;
(overall or after 6 months) mass decreases;
correct reference to figures;
[3]
[Total: 23]
3 (a) (i) A
C
[2]
(ii) 2 from
elongated body shape / eyes / scales / no legs or limbs;;
[2]
[Total: 4]
