Cambridge A Level Marine Science 9693 — 2022 Oct/Nov Paper 1 · Variant 3

This document has 12 pages. [Turn over Cambridge International AS & A Level * 5 1 2 6 5 7 8 7 9 4 * MARINE SCIENCE 9693/13 Paper 1 AS Level Theory October/November 2022 1 hour 45 minutes You must answer on the question paper. No additional materials are needed. INSTRUCTIONS ● Answer all questions. ● Use a black or dark blue pen. You may use an HB pencil for any diagrams or graphs. ● Write your name, centre number and candidate number in the boxes at the top of the page. ● Write your answer to each question in the space provided. ● Do not use an erasable pen or correction fluid. ● Do not write on any bar codes. ● You may use a calculator. ● You should show all your working and use appropriate units. INFORMATION ● The total mark for this paper is 75. ● The number of marks for each question or part question is shown in brackets [ ]. DC (KN) 320235 © UCLES 2022

2 9693/13/O/N/22 © UCLES 2022 Section A Answer all questions in this section. 1 (a) Many large molecules are made from small molecules. Complete Table 1.1. Table 1.1 small molecules large molecule main chemical elements in the molecule … cellulose … … … … protein carbon, hydrogen, oxygen, nitrogen, sulfur fatty acids and glycerol … … … … [5] (b) Fig. 1.1 shows part of the carbon cycle in the ocean. phytoplankton A A A C D B NOT TO SCALE Fig. 1.1

3 9693/13/O/N/22 © UCLES 2022 [Turn over (i) Give the name of the processes A, B and C. A … B … C … [3] (ii) At D, over millions of years, fossil fuels may form. Describe how carbon in fossil fuels may be returned to the atmosphere. … … … … … … [3] (iii) At D, over millions of years, rocks may form. Describe how these rocks form. … … … … [2] [Total: 13]

4 9693/13/O/N/22 © UCLES 2022 2 (a) Table 2.1 shows part of the classification of the leatherback turtle. All turtles are in the same phylum as bony fish. Table 2.1 group leatherback turtle classification domain … kingdom … phylum … class Reptilia order Testudines family Dermochelyidae genus Dermochelys species coriacea (i) Complete Table 2.1 to give the domain, kingdom and phylum of the leatherback turtle. [3] (ii) Give the binomial name of the leatherback turtle. … [1]

5 9693/13/O/N/22 © UCLES 2022 [Turn over (b) Fig. 2.1 shows a leatherback turtle with attached remora fish. Fig. 2.1 (i) Remora fish have a commensal relationship with leatherback turtles. Define the term commensal. … … … … [2] (ii) Scientists have investigated the effect of remora fish on the swimming efficiency of turtles. Suggest how the presence of remora fish may be a disadvantage to a turtle when the turtle is swimming. … … … … … … [3] [Total: 9]

6 9693/13/O/N/22 © UCLES 2022 3 (a) Describe the differences between liquid water and ice in terms of the arrangement and the movement of water molecules. 1 … … 2 … … [2] (b) Fig. 3.1 shows the arrangement of an oxygen atom and hydrogen atoms in a water molecule. H x x O H Fig. 3.1 (i) What is represented by the crosses (x) in Fig. 3.1? … [1] (ii) Name the type of bond between oxygen and hydrogen in the water molecule shown in Fig. 3.1. … [1] (iii) Describe how a bond forms between two water molecules. … … … … … … … … [4]

7 9693/13/O/N/22 © UCLES 2022 [Turn over (iv) Explain how the bonds between water molecules affect the density of liquid water and of ice. … … … … … … [3] (v) Describe one way that the relative density of liquid water and of ice affects marine organisms. … … [1] (vi) State three factors that affect the density of sea water. 1 … 2 … 3 … [3] [Total: 15]

8 9693/13/O/N/22 © UCLES 2022 4 (a) A chimney with a height of 60 m above the ocean floor has been discovered at a hydrothermal vent. The ocean depth from the surface to the ocean floor is 800 m at this point. Calculate the height of the chimney as a percentage of the ocean depth. Show your working. …% [2] (b) Table. 4.1 shows the productivity at two hydrothermal vents. Table 4.1 vent total productivity / g carbon year –1 A 4.7 × 106 B 7.4 × 103 (i) Calculate how many times greater the productivity is at vent A compared with vent B. Show your working. Give your answer to an appropriate number of significant figures. … [3] (ii) Suggest one reason for the lower productivity at vent B. … … [1]

9 9693/13/O/N/22 © UCLES 2022 [Turn over (iii) Productivity at hydrothermal vents affects the total biomass of the food web in the ocean around the vent. A student predicted vent A would increase the biomass in a larger volume of ocean than vent B. Explain why vent A may increase the biomass in a larger volume than vent B. … … … … [2] [Total: 8]

10 9693/13/O/N/22 © UCLES 2022 Section B Answer all questions in this section. 5 (a) Explain the effect of increasing ocean temperature on the solubility of salts and gases. … … … … … … … … … … [5] (b) Describe the impact of decreasing concentrations of oxygen and carbon dioxide on marine organisms. … … … … … … … … … … … … … … [7] [Total: 12]

11 9693/13/O/N/22 © UCLES 2022 [Turn over 6 (a) (i) Biodiversity can be considered at three different levels. Describe the three different levels of biodiversity and explain why all three levels should be considered. … … … … … … … … … … … … … … [7] (ii) Explain, with examples, how coral reefs contribute to stable abiotic factors in the environment. … … … … … … … … … … … … [6]

12 9693/13/O/N/22 © UCLES 2022 The boundaries and names shown, the designations used and the presentation of material on any maps contained in this question paper/insert do not imply official endorsement or acceptance by Cambridge Assessment International Education concerning the legal status of any country, territory, or area or any of its authorities, or of the delimitation of its frontiers or boundaries. 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. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge Assessment International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cambridgeinternational.org after the live examination series. Cambridge Assessment International Education is part of Cambridge Assessment. Cambridge Assessment is the brand name of the University of Cambridge Local Examinations Syndicate (UCLES), which is a department of the University of Cambridge. (b) Describe the importance of mangrove forests to human communities. … … … … … … … … … … [5] [Total: 18]

This document consists of 12 printed pages. © UCLES 2022 [Turn over Cambridge International AS & A Level MARINE SCIENCE 9693/13 Paper 1 AS Level Theory Paper October/November 2022 MARK SCHEME Maximum Mark: 75 Published 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 International will not enter into discussions about these mark schemes. Cambridge International is publishing the mark schemes for the October/November 2022 series for most Cambridge IGCSE™, Cambridge International A and AS Level components and some Cambridge O Level components.

9693/13 Cambridge International AS & A Level – Mark Scheme PUBLISHED October/November 2022 © UCLES 2022 Page 2 of 12 Generic Marking Principles These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these marking principles. GENERIC MARKING PRINCIPLE 1: Marks must be awarded in line with: • the specific content of the mark scheme or the generic level descriptors for the question • the specific skills defined in the mark scheme or in the generic level descriptors for the question • the standard of response required by a candidate as exemplified by the standardisation scripts. GENERIC MARKING PRINCIPLE 2: Marks awarded are always whole marks (not half marks, or other fractions). GENERIC MARKING PRINCIPLE 3: Marks must be awarded positively: • marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond the scope of the syllabus and mark scheme, referring to your Team Leader as appropriate • marks are awarded when candidates clearly demonstrate what they know and can do • marks are not deducted for errors • marks are not deducted for omissions • answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the question as indicated by the mark scheme. The meaning, however, should be unambiguous. GENERIC MARKING PRINCIPLE 4: Rules must be applied consistently, e.g. in situations where candidates have not followed instructions or in the application of generic level descriptors.

9693/13 Cambridge International AS & A Level – Mark Scheme PUBLISHED October/November 2022 © UCLES 2022 Page 3 of 12 GENERIC MARKING PRINCIPLE 5: Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may be limited according to the quality of the candidate responses seen). GENERIC MARKING PRINCIPLE 6: Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or grade descriptors in mind. Science-Specific Marking Principles 1 Examiners should consider the context and scientific use of any keywords when awarding marks. Although keywords may be present, marks should not be awarded if the keywords are used incorrectly. 2 The examiner should not choose between contradictory statements given in the same question part, and credit should not be awarded for any correct statement that is contradicted within the same question part. Wrong science that is irrelevant to the question should be ignored. 3 Although spellings do not have to be correct, spellings of syllabus terms must allow for clear and unambiguous separation from other syllabus terms with which they may be confused (e.g. ethane / ethene, glucagon / glycogen, refraction / reflection). 4 The error carried forward (ecf) principle should be applied, where appropriate. If an incorrect answer is subsequently used in a scientifically correct way, the candidate should be awarded these subsequent marking points. Further guidance will be included in the mark scheme where necessary and any exceptions to this general principle will be noted. 5 ‘List rule’ guidance For questions that require n responses (e.g. State two reasons …): • The response should be read as continuous prose, even when numbered answer spaces are provided. • Any response marked ignore in the mark scheme should not count towards n. • Incorrect responses should not be awarded credit but will still count towards n. • Read the entire response to check for any responses that contradict those that would otherwise be credited. Credit should not be awarded for any responses that are contradicted within the rest of the response. Where two responses contradict one another, this should be treated as a single incorrect response. • Non-contradictory responses after the first n responses may be ignored even if they include incorrect science.

9693/13 Cambridge International AS & A Level – Mark Scheme PUBLISHED October/November 2022 © UCLES 2022 Page 4 of 12 6 Calculation specific guidance Correct answers to calculations should be given full credit even if there is no working or incorrect working, unless the question states ‘show your working’. For questions in which the number of significant figures required is not stated, credit should be awarded for correct answers when rounded by the examiner to the number of significant figures given in the mark scheme. This may not apply to measured values. For answers given in standard form (e.g. a  10n) in which the convention of restricting the value of the coefficient (a) to a value between 1 and 10 is not followed, credit may still be awarded if the answer can be converted to the answer given in the mark scheme. Unless a separate mark is given for a unit, a missing or incorrect unit will normally mean that the final calculation mark is not awarded. Exceptions to this general principle will be noted in the mark scheme. 7 Guidance for chemical equations Multiples / fractions of coefficients used in chemical equations are acceptable unless stated otherwise in the mark scheme. State symbols given in an equation should be ignored unless asked for in the question or stated otherwise in the mark scheme.

9693/13 Cambridge International AS & A Level – Mark Scheme PUBLISHED October/November 2022 © UCLES 2022 Page 5 of 12 • This mark scheme will use the following abbreviations: ; separates marking points / separates alternatives within a marking point () contents of brackets are not required but should be implied / the contents set the context of the answer R reject A accept (answers that are correctly cued by the question or guidance you have received) I ignore (mark as if this material was not present) AW alternative wording (where responses vary more than usual, accept other ways of expressing the same idea) AVP alternative valid point (where a greater than usual variety of responses is expected) ORA or reverse argument underline actual word underlined must be used by the candidate (grammatical variants excepted) MAX indicates the maximum number of marks that can be awarded + statements on both sides of the + are needed for that mark OR separates two different routes to a mark point and only one should be awarded ECF error carried forward (credit an operation from a previous incorrect response)

9693/13 Cambridge International AS & A Level – Mark Scheme PUBLISHED October/November 2022 © UCLES 2022 Page 6 of 12 Question Answer Marks 1(a) small molecule large molecule main chemical elements in the molecule glucose ; carbon / C + hydrogen / H + oxygen / O ; amino acid(s) ; lipid(s) / fat(s) / triacylglycerol(s) / triglyceride(s) ; carbon / C + hydrogen / H + oxygen / O ; 5 1(b)(i) (A) respiration ; (B) feeding / consumption ; (C) (sinking and) decomposition (on the sea bed) ; 3 1(b)(ii) drilling / extraction (from ocean / sea floor) ; combustion / burning ; (combustion / burning releases) carbon dioxide ; 3 1(b)(iii) any 2 from: pressure / compacted ; from (organic / inorganic) sediments (accumulating above) ; cementation / precipitation (of minerals) ; 2

9693/13 Cambridge International AS & A Level – Mark Scheme PUBLISHED October/November 2022 © UCLES 2022 Page 7 of 12 Question Answer Marks 2(a)(i) Group Leatherback turtle classification domain eukaryote / eukaryota / eukarya ; kingdom animal(ia) ; phylum chordata / chordate(s) ; class Reptilia order Testundines family Dermochelyidae genus Dermochelys species coriacea 3 2(a)(ii) Dermochelys coriacea 1 2(b)(i) one organism / the remora fish, benefits (from the relationship by gaining more food) ; other organism / manta / turtle / host, neither benefits nor is harmed ; 2 2(b)(ii) any 3 from: increased drag OR decreased hydrodynamic efficiency ; reduces (swimming) speed ; more likely to be caught by a predator ; less likely to catch prey ; more food / energy required (to swim same speed / distance) ; 3

9693/13 Cambridge International AS & A Level – Mark Scheme PUBLISHED October/November 2022 © UCLES 2022 Page 8 of 12 Question Answer Marks 3(a) irregular arrangement in liquid + regular / lattice arrangement / rigid pattern in solid ; in solid / ice, molecules vibrate (in their places) + in liquid / water, molecules move past each other / move freely AW ; 2 3(b)(i) electron(s) (from the hydrogen atom) ; 1 3(b)(ii) covalent ; 1 3(b)(iii) any 4 from: hydrogen atoms (in water molecule) are slightly positive(ly charged) ; oxygen atoms (in water molecule) are slightly negative(ly charged) ; due to oxygen attracting the electrons more strongly than hydrogen ; oxygen (from one water molecule) is attracted to hydrogen (in another water molecule) ; reference to dipole ; 4 3(b)(iv) any 3 from: in liquid / water, the molecule form fewer hydrogen bonds (with other molecules) ; this causes the molecules to be closer together (in liquid) ; therefore more molecules per unit volume ; therefore density is higher ; 3 3(b)(v) any 1 from: ice is a (thermal) insulator so prevents, water / organisms below from freezing ; (floating) ice forms a platform for marine organisms / mammals ; AVP ; 1 3(b)(vi) temperature ; salinity / mineral ion(s) content / salt content ; pressure ; 3

9693/13 Cambridge International AS & A Level – Mark Scheme PUBLISHED October/November 2022 © UCLES 2022 Page 9 of 12 Question Answer Marks 4(a) 60 ×100 800 ; 7.5 ; 2 4(b)(i) 6 3 4.7 ×1 0 7.4 ×1 0 ; 635 OR 640 ;; 3 4(b)(ii) any 1 from: low(er) availability / concentration of (dissolved) nutrients / minerals ; pressure too high / low ; temperature too high /low ; may be newer (therefore producer population not established) ; may be older (therefore no longer active) ; 1 4(b)(iii) (vent A has higher productivity) so more carbon is fixed (per year) ; therefore supports food web further from the vent / plume ; 2

9693/13 Cambridge International AS & A Level – Mark Scheme PUBLISHED October/November 2022 © UCLES 2022 Page 10 of 12 Question Answer Marks 5(a) any 5 from: (increasing ocean temperature) increases solubility of salts ; (because) water molecules have more kinetic energy ; therefore interact more frequently with (salt) ions / water molecules (have sufficient KE to) overcome the attractive forces between the ions in salts ; (increasing ocean temperature) decreases solubility of gases ; (because) gas molecules have more kinetic energy ; therefore more likely to leave solution / water ; 5 5(b) any 7 from: lower carbon dioxide (dissolved) concentration means less photosynthesis ; causing lower productivity ; therefore smaller populations ; lower carbon dioxide means less acidic conditions ; named effect (less erosion) ; lower oxygen means lower (rate of) respiration ; therefore slower release of energy ; therefore lower growth rate ; smaller populations ; AVP ; 7

9693/13 Cambridge International AS & A Level – Mark Scheme PUBLISHED October/November 2022 © UCLES 2022 Page 11 of 12 Question Answer Marks 6(a)(i) any 7 from: genetic diversity ; which is the variation in the genes / DNA / alleles / genotypes ; within a species ; species diversity ; which is the number of species ; and also their relative abundance ; ecological diversity ; which is variation in ecosystems on a regional + global level ; no single level gives full measure of biodiversity ; allows biodiversity to be considered at a global level and at an individual species level ; all three levels are linked / interrelated ; highlights the importance of every species in a stable ecosystem ; 7 6(a)(ii) any 6 from: physical contribution to shorelines ; preventing erosion ; (by) reducing wave energy / height / speed ; providing solid substrate ; for coral polyps to attach to ; climate control ; zooxanthellae photosynthesising ; using carbon dioxide (and releasing oxygen) / therefore reducing / slowing global warming ; reducing ocean acidification ; AVP ;; 6

9693/13 Cambridge International AS & A Level – Mark Scheme PUBLISHED October/November 2022 © UCLES 2022 Page 12 of 12 Question Answer Marks 6(b) any 5 from: habitat for (human) food species ; nursery / breeding ground ; juveniles shelter in (prop) roots ; tourism ; coastal protection ; timber / lumber source ; fuel source ; medicinal plants / products ; decrease carbon dioxide (in atmosphere) through photosynthesis ; sink / store of carbon (compounds) ; 5