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UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS
General Certificate of Education
Advanced Subsidiary Level and Advanced Level
* 2 3 1 5 9 7 1 2 5 4 *
9693/02
MARINE SCIENCE
Paper 2 AS Data Handling and Free Response
October/November 2011
1 hour 15 minutes
Candidates answer on the Question Paper.
No Additional Materials are required.
READ THESE INSTRUCTIONS FIRST
Write your Centre number, candidate number and name on all the work you hand in.
Write in dark blue or black pen.
You may use a pencil for any diagrams, graphs or rough work.
Do not use staples, paper clips, highlighters, glue or correction fluid.
DO NOT WRITE IN ANY BARCODES.
Answer all questions.
Section A
Answer all questions.
Write your answers in the spaces provided on the question paper.
Section B
Answer all questions.
Write your answers on the lined pages provided.
At the end of the examination, fasten all your work securely together.
The number of marks is given in brackets [ ] at the end of each question or part
question.
For Examiner’s Use
1
2
3
4
Total
This document consists of 6 printed pages and 6 lined pages.
DC (NF/CGW) 36113/3
© UCLES 2011
[Turn over
2
Section A
Answer all questions.
1
The ocean floor surrounding hydrothermal vents is colonised by a range of animals including
tubeworms and molluscs. Tubeworms quickly colonise hydrothermal vents, followed by
animals such as mussels and other species of worms. Tubeworms contain chemosynthetic
bacteria.
(a) Describe the properties of sea water in a hydrothermal vent.
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(b) Researchers carried out an investigation into colonisation around a hydrothermal vent.
The researchers investigated the effect of the mussel Bathiomodiolus thermophilus on
the colonisation of a vent by the tube worm Riftia pachyptila.
The researchers put forward the following hypothesis:
The presence of Bathiomodiolus thermophilus prevents colonisation by the tube
worm Riftia pachyptila.
The stages in this investigation were
© UCLES 2011
•
the area around a hydrothermal vent in the East Pacific Rise was cleared of
the animal community
•
about 200 individual mussels, Bathiomodiolus thermophilus, were placed in
the cleared area
•
the area was left for one year
•
the number of each species of animal was then recorded
•
the biomass of each species was also recorded.
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The results of this investigation are shown in Table 1.1.
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Table 1.1
species
number of individuals
total biomass / g
650
3250.00
23
0.14
Bathiomodiolus thermophilus
(mussel)
6
0.23
Nereis sandersi
(worm)
2
0.27
Riftia pachyptila
(tubeworm)
Tevnia jerichonona
(tubeworm)
(i)
Calculate the mean biomass of Riftia pachyptila.
Show your working.
mean biomass ................................................. [2]
(ii)
Use the information in Table 1.1 to describe the composition of this community.
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(iii)
State whether the results of this investigation support the hypothesis that the
presence of Bathiomodiolus thermophilus prevents colonisation by the tubeworm
Riftia pachyptila.
Give an explanation for your answer.
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(c) The researchers also measured the tube length and the percentage of the tube occupied
by individual tube worms, Riftia pachyptila.
The results are shown in Fig. 1.1.
100
90
80
percentage of
the tube
occupied by
each
individual
70
60
50
40
30
20
10
0
0
20
40
60
80
100
120
140
tube length / cm
Fig. 1.1
Using the information in Fig. 1.1, suggest why using tube length may not be a reliable
way of measuring the growth of Riftia pachyptila.
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..................................................................................................................................... [2]
[Total: 13]
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2
An estuary is formed where a river flows into the sea.
Fig. 2.1 shows part of the Estuary of St. Lawrence in northern Canada. The figures give the
surface water salinities.
Chicoutimi
1,5
29 28 27
1,5 3
6
Tadoussac
15
18
25
22
26
Rimouski
Trois-Pistoles
Rivière-du-Loup
20
La Malbaie
Baie-Saint-Paul
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15
La Pocatière
10
5
1
0
L’Islet
Montmagny
25 km
Quebec
Fig. 2.1
(a) (i)
With reference to Fig. 2.1, describe how the surface salinity changes as the distance
away from Quebec increases.
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............................................................................................................................. [2]
(ii)
Suggest explanations for the changes you have described.
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(b) Suggest why, in an estuary, the salinity of the water usually increases as the depth
increases.
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..................................................................................................................................... [2]
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Section B
Answer all questions in this section on the lined pages provided.
3
4
(a) Describe the conditions required for the growth of warm water corals and for the formation of
a coral reef.
[5]
(b) Explain how carbon dating can provide evidence for the growth of coral reefs.
[6]
(c) Suggest how coral reefs can provide evidence for changes in sea level.
[4]
(a) State what is meant by the term cyclone and describe the factors required for the development
of a tropical cyclone.
[6]
(b) Describe the causes of El Niño events in the Pacific Ocean.
[5]
(c) Suggest why El Niño events affect fish catches in the Pacific Ocean.
[4]
[Total: 30]
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Copyright Acknowledgements:
Question 1
Question 2
© Govenar et al; Composition of a One-Year-Old Riftia pachyptila Community Following a Clearance Experiment: Insight
to Succession Patterns at Deep-Sea Hydrothermal Vents; Marine Biological Laboratory; 2004.
© http://www.qc.ec.gc.ca/faune/biodiv/en/fish/sw_salinity.html; Environment Canada.
Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every
reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the
publisher will be pleased to make amends at the earliest possible opportunity.
University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of
Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.
© UCLES 2011
9693/02/O/N/11