Cambridge IGCSE Biology (9-1) 0970 — 2024 May/June Paper 6 · Variant 2

This document has 12 pages. Any blank pages are indicated. [Turn over Cambridge IGCSE™(9–1) * 9 9 2 4 1 9 3 0 1 5 * BIOLOGY 0970/62 Paper 6 Alternative to Practical May/June 2024 1 hour 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 40. ● The number of marks for each question or part question is shown in brackets [ ]. DC (SL) 342482 © UCLES 2024

2 0970/62/M/J/24 © UCLES 2024 1 A student investigated the effect of acid concentration on the rate of diffusion in agar jelly. The student was given three test‑tubes containing bromothymol blue indicator in agar jelly. Bromothymol blue is a blue indicator that turns yellow in the presence of an acid. The student used this method: Step 1 label three beakers A1, A2 and A3 Step 2 put 20 cm3 of 1 mol per dm3 hydrochloric acid solution into beaker A1 Step 3 put 2 cm3 of 1 mol per dm3 hydrochloric acid solution into beaker A2 Step 4 add 18 cm3 of distilled water to the hydrochloric acid solution in beaker A2 Step 5 use a clean syringe to transfer 2 cm3 of the solution from beaker A2 to beaker A3 Step 6 add 18 cm3 of distilled water to beaker A3 Table 1.1 shows the final concentrations of the hydrochloric acid solution in each beaker. Table 1.1 beaker final concentration of the hydrochloric acid solution / mol per dm3 final volume of the solution / cm3 A1 1.00 20 A2 0.10 ………. A3 0.01 20 (a) (i) Complete Table 1.1 by calculating the final volume of the solution in beaker A2. Write your answer in Table 1.1. [1] Step 7 label the three test‑tubes that contain the bromothymol blue indicator in agar jelly A1, A2 and A3 Step 8 use a syringe to transfer 10 cm3 of the hydrochloric acid solution from beaker A1 to test‑tube A1 Step 9 use a syringe to transfer 10 cm3 of the hydrochloric acid solution from beaker A2 to test‑tube A2 Step 10 use a syringe to transfer 10 cm3 of the hydrochloric acid solution from beaker A3 to test‑tube A3 Step 11 place the three test‑tubes into a water‑bath at 35 °C Step 12 start a stop‑clock and leave the test‑tubes in the water‑bath for 20 minutes Step 13 after 20 minutes, remove the test‑tubes from the water‑bath Step 14 measure the temperature of the water in the water‑bath.

3 0970/62/M/J/24 © UCLES 2024 [Turn over Fig. 1.1 shows the three test‑tubes after they were removed from the water‑bath in step 13. hydrochloric acid yellow agar jelly blue agar jelly yellow agar jelly blue agar jelly agar jelly containing bromothymol blue indicator A1 A2 A3 Fig. 1.1 (ii) Measure the height of the yellow agar jelly in each test‑tube shown in Fig. 1.1. Prepare a table and record the results of the investigation. Include in your table: • your measurements from Fig. 1.1 • the final concentration of hydrochloric acid. [4]

4 0970/62/M/J/24 © UCLES 2024 (iii) State a conclusion for the investigation. … … … [1] (iv) Identify the independent variable and the dependent variable in this investigation. independent variable … … dependent variable … … [2] (v) Fig. 1.2 shows the reading on the thermometer in step 14. 10 20 30 °C Fig. 1.2 Record the temperature of the water in the water‑bath at the end of the investigation, shown in Fig. 1.2. temperature … °C [1] (vi) The student stated that the change in the temperature of the water‑bath was not a significant source of error in the investigation. Explain why the student was correct to state this. … … … [1]

5 0970/62/M/J/24 © UCLES 2024 [Turn over (vii) Suggest a control experiment for this investigation. … … … [1] (viii) The student repeated the investigation but left the test‑tubes in the water‑bath for 30 minutes instead of 20 minutes. Suggest how the results for this second investigation would differ from the results for the first investigation. … … … [1]

6 0970/62/M/J/24 © UCLES 2024 (b) In an experiment, a student cut different‑sized cubes of agar containing bromothymol blue indicator. The student placed the cubes in hydrochloric acid and measured the time taken for each cube to become yellow. The results are shown in Table 1.2. Table 1.2 length of the cube sides / mm volume of the cube / mm3 time taken for the cubes to become yellow / s 2 8 35 4 ……….. 60 6 216 170 8 512 275 10 1000 445 (i) Complete Table 1.2 by calculating the volume of the 4 mm cube. Write your answer in Table 1.2. [1]

7 0970/62/M/J/24 © UCLES 2024 [Turn over (ii) Plot a line graph on the grid of the length of the cube sides against the time taken for the cubes to become yellow. [4] (iii) Use your graph to estimate the time taken for a cube with a side length of 3 mm to become yellow. Show on your graph how you obtained your answer. … s [2] (iv) State two variables that should have been kept constant in this investigation. 1 … … 2 … … [2] [Total: 21]

8 0970/62/M/J/24 © UCLES 2024 2 (a) When a seed germinates it grows into a seedling. Fig. 2.1 is a photograph of a seedling. A B Fig. 2.1 (i) Make a large drawing of the seedling shown in Fig. 2.1. [4]

9 0970/62/M/J/24 © UCLES 2024 [Turn over (ii) Line AB represents the width of the seedling. Measure the length of line AB on Fig. 2.1. length of line AB … mm The actual width of the seedling is 9 mm. Calculate the magnification of the seedling in Fig. 2.1 using the formula and your measurement. magnification = length of line AB in Fig. 2.1 actual width of the seedling Give your answer to two significant figures. Space for working. … [3]

10 0970/62/M/J/24 © UCLES 2024 (iii) Fig. 2.2 shows photographs of two different seedlings, P and Q. P Q Fig. 2.2 Describe one visible similarity and two visible differences between seedling P and seedling Q in Fig. 2.2. similarity 1 … … difference 1 … … difference 2 … … [3] (b) As seedlings grow, they change starch into reducing sugars. Describe the methods you would use to test a sample of seedlings for starch and reducing sugars. starch test … … … reducing sugar test … … … [3]

11 0970/62/M/J/24 © UCLES 2024 (c) When light shines from one side, seedlings grow towards the light. Fig. 2.3 shows a diagram of a seedling growing towards a light source. The angle of growth is shown on the diagram. light source Fig. 2.3 Plan an investigation to find out how light intensity affects the angle at which the seedling grows. … … … … … … … … … … … … … [6] [Total: 19]

12 0970/62/M/J/24 © UCLES 2024 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. BLANK PAGE

This document consists of 10 printed pages. © Cambridge University Press & Assessment 2024 [Turn over Cambridge IGCSE™ (9–1) BIOLOGY (9–1) 0970/62 Paper 6 Alternative to Practical May/June 2024 MARK SCHEME Maximum Mark: 40 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 May/June 2024 series for most Cambridge IGCSE, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components.

0970/62 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2024 © Cambridge University Press & Assessment 2024 Page 2 of 10 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 descriptions 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.

0970/62 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2024 © Cambridge University Press & Assessment 2024 Page 3 of 10 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.

0970/62 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2024 © Cambridge University Press & Assessment 2024 Page 4 of 10 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. Mark scheme abbreviations  ; separates marking points  / alternative responses for the same marking point  R reject the response  A accept the response  I ignore the response  ecf error carried forward  AVP any valid point  ora or reverse argument  AW alternative wording  underline actual word given must be used by candidate (grammatical variants excepted)  ( ) the word / phrase in brackets is not required but sets the context

0970/62 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2024 © Cambridge University Press & Assessment 2024 Page 5 of 10 Question Answer Marks Guidance 1(a)(i) 20 (cm3) ; 1 A 18 1(a)(ii) 1 table drawn with headings underlined and minimum of two, columns / rows ; 2 suitable headings with units for: (final acid) concentration (in) mol per dm3 and height (of yellow agar) (in) mm / cm ; 3 three concentrations and three heights recorded ; 4 all heights correct 1 mm ; 4 concentration / mol per dm3 height / mm 1.00 0.10 0.01 25 (1) 14 (1) 5 (1) 1(a)(iii) an increase in the concentration (of the hydrochloric acid solution) increases the rate of diffusion ; ora 1 1(a)(iv) IV: concentration (of hydrochloric acid solution) ; DV: height of yellow (agar) ; 2 1(a)(v) 23 (°C) ; 1 1(a)(vi) any change in temperature would affect all three test-tubes equally / AW ; 1 1(a)(vii) any one from: use water instead of acid ; only add water to the agar jelly ; 1 1(a)(viii) height of the yellow (agar) would increase (in all three test- tubes) ; 1

0970/62 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2024 © Cambridge University Press & Assessment 2024 Page 6 of 10 Question Answer Marks Guidance 1(b)(i) 64 ; 1 1(b)(ii) axes labelled with units ; suitable linear scale and plotting area occupies at least half the grid in both directions ; five points plotted accurately ± half small square ; suitable line drawn ; 4 1(b)(iii) any indication on graph at 3 mm / indication of correct value on the time axis ; correct value recorded from candidate’s graph ; 2 1(b)(iv) any two from:  temperature  concentration of acid  volume of acid  type / pH, of acid  type of agar  density / solidity / concentration, of agar  concentration of indicator  volume of indicator  type of indicator ;; 2

0970/62 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2024 © Cambridge University Press & Assessment 2024 Page 7 of 10 Question Answer Marks Guidance 2(a)(i) single clear unbroken outline ; size greater than half of space provided ; detail 1: proportions plumule vs radical ; detail 2: two outermost curved leaves ; 4 2(a)(ii) 31 ±1(mm) ; () 3.4 ;; 3 MP1 correct measurement of line AB MP2 correct calculation to any number of significant figures MP3 correct rounding to two significant figures ecf from previous mark point if supported by workings R MP2 if unit of measurement given with the calculated value () 3.3 (for AB of 30 mm) () 3.5 or 3.6 (for AB of 32 mm)

0970/62 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2024 © Cambridge University Press & Assessment 2024 Page 8 of 10 Question Answer Marks Guidance 2(a)(iii) one similarity from:  root / radicle / AW, present  (any) structure, pointing / AW, downwards  seed coat / seed covering / testa / AW, present / split  side roots / root hairs, present ; two differences from: P Q marks on / darker, seed coat / AW OR no marks on / paler, seed coat / AW shoot / plumule / stem / stalk OR no, shoot / plumule / stem / stalk (root is) not, hairy / furry / fibrous / feathery / branched OR (root is) hairy / furry / fibrous / feathery / more branched thick (side) roots / AW OR thin (side) roots / AW has leaves OR has no leaves oval, seed / AW OR round, seed / AW larger / longer OR smaller / shorter ;; 3 MP1 similarity 1 MP2 difference 1 MP3 difference 2

0970/62 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2024 © Cambridge University Press & Assessment 2024 Page 9 of 10 Question Answer Marks Guidance 2(b) starch: iodine solution ; reducing sugar: Benedict’s solution ; heat ; 3

0970/62 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2024 © Cambridge University Press & Assessment 2024 Page 10 of 10 Question Answer Marks Guidance 2(c) any six from: 1 independent variable: use at least two different light intensities ; 2, 3 and 4 variables kept constant ;;; max three from:  age of plant  type / species, of plant  (starting) surface area / number of leaves / size / height  temperature  wind speed / humidity  light, wavelength / colour  soil type / AW / fertiliser / soil minerals / soil pH  volume / amount, of water supplied  time 5 and 6 detail of method ;; max two from:  method of changing the light intensity e.g. different lamp distances / dimmer switch altered / different bulbs / different lamps / different power lamps / different light sources  method of measuring angle of seedling e.g. use a protractor / measure on a photograph / use a ruler to measure from the soil to the top of the seedling  use of a heat shield 7 repeat the whole investigation at least two more times ; 8 relevant safety point ; 6