Marking Guidelines 2010 examination June series. Biology Unit 6T A2 Investigative Skills Assignment. General Certificate of Education BIO6T/P10/MG

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1 Genera Certificate of Education Bioogy Unit 6T A2 Investigative Skis Assignment BIO6T/P10/MG Marking Guideines 2010 examination June series WMP/Jun10/BIO6T/P10/MG

2 Bioogy - AQA GCE Unit 6T/P/Marking Guideines/2010 June series Marking Guideines are prepared by the Principa Moderator and considered, together with the reevant questions, by a pane of subject teachers. Copyright 2010 AQA and its icensors. A rights reserved. COPYRIGHT AQA retains the copyright on a its pubications. However, registered centres for AQA are permitted to copy materia from this booket for their own interna use, with the foowing important exception: AQA cannot give permission to centres to photocopy any materia that is acknowedged to a third party even for interna use within the centre. Set and pubished by the Assessment and Quaifications Aiance. The Assessment and Quaifications Aiance (AQA) is a company imited by guarantee registered in Engand and Waes (company number ) and a registered charity (registered charity number ). Registered address: AQA, Devas Street, Manchester M15 6EX. Dr Michae Cresswe Director Genera 2

3 Bioogy - AQA GCE Unit 6T/P/Marking Guideines/2010 June series Guidance for teachers marking Bioogy ISAs Genera principes In genera, you are ooking for evidence that the candidate knows and understands the point required by the Marking Guideines. It is important to mark what the candidate has written, not to assume what may have been intended. It is aso important to make sure that a vaid point is in the correct context. Individua words or phrases where the overa answer does not appy to the question asked shoud not be credited. Conventions The foowing conventions are used in the Marking Guideines. A semicoon (;) separates each marking point An obique stroke (/) separates aternatives within a marking point Underining of a word or phrase means that the term must be used For exampe anaphase, the term must appear For exampe... and..., both items must be present for a mark Brackets are used to indicate contexts for which a marking point is vaid. This context may be impied by a candidate's answer 'Accept' and 'reject' show answers which shoud be aowed or not aowed. Additiona instructions are shown in the fina coumn Max refers to the maximum mark that can be awarded for a particuar question or part question. The Marking Guideines show the minimum acceptabe answer(s) for each marking point. A better, more detaied, or more advanced answer shoud aways be accepted, provided that it covers the same key point. Marking Guideines cannot give every possibe aternative wording - equivaent phrasing of answers shoud be accepted. For exampe the water potentia is higher in the ces is equivaent to the water potentia is ess negative in the ces. It is, however, important to be sure that the minimum requirement of the Marking Guideines is met and that the point is made unambiguousy. Converse answers are normay acceptabe, uness the wording of the question rues this out. For exampe, 'the water potentia is ower in the soution is an acceptabe converse of the water potentia is higher in the ce. Very occasionay, a candidate wi give a bioogicay correct answer that is not covered in the Marking Guideines. If it is equivaent in standard to the Marking Guideine answers, it shoud be credited. In this case, write the word vaid. A marking points are awarded independenty, uness a ink between points is specified in the Marking Guideines. 3

4 Bioogy - AQA GCE Unit 6T/P/Marking Guideines/2010 June series The mechanics of marking Aways mark in red ink. Make sure that some red ink appears on every page on which the candidate has written. For each mark awarded, put a tick cose to the marking point. In a cases, a tick shoud equa one mark and the tota number of ticks shoud match the mark totas in the margins. The tota mark for each part answer shoud be written in the right hand margin. Put a cross against incorrect points. It is hepfu to indicate omissions of key words or incompete answers with a Λ symbo, and to highight irreevancies or contradictions by underining. It is aso hepfu to write brief comments to expain the reason for awarding or withhoding a mark when the answer does not obviousy match the Marking Guideines. When marking answers with many marking points, the points wi be numbered. The points do not have to appear in the candidate s response in the order in the Marking Guideines. The appropriate number must be paced aongside the tick. This heps to carify where a specific point has been awarded and makes moderation much easier. It aso heps to avoid awarding the same point twice. Disquaifiers A correct point shoud be disquaified when the candidate contradicts it in the same answer. Indicate this on the script by 'dq'. If a tick has aready been paced against a vaid point, ensure that it is ceary deeted. Note that there is no penaty for incorrect points which are not contradictory, or for surpus or neutra information. The ist rue When a question asks for a specific number of points, and the candidate gives more, the genera rue is that any wrong answer cances a correct answer. For exampe, if a question asks for two points and three answers are given, two correct and one ceary wrong, the mark awarded is one, whatever the order of the answers. This prevents candidates from gaining fu marks from a ist of right and wrong answers. Answer Marks Comment Oxygen, gucose 2 Both correct Oxygen, carbon dioxide 1 One correct, one incorrect Carbon dioxide, oxygen, gucose 1 Carbon dioxide is ceary incorrect and caces one of the marks Oxygen, gucose, water 2 Regard water as a neutra point. It is not worth a mark but it is not incorrect Two or more correct points on the same answer ine shoud be credited. 'Neutra' points, i.e. ones which are not creditworthy but not actuay incorrect, shoud not negate a correct answer. Speing Reasonaby cose phonetic speings shoud be credited. However, any misspeing of technica terms which can easiy be confused, such as intermediate between mitosis and meiosis, shoud resut in the reevant marking point being withhed. Terms ike this wi be indicated in the fina coumn in the Marking Guideines to show that misspeings must not be credited. 4

5 Bioogy - AQA GCE Unit 6T/P/Marking Guideines/2010 June series Stage 2 (NB no marks are awarded for the tabe, Stage 1 at A2) Question Marking Guidance Mark Comments 1 Correct cacuations of the reciproca distance squared; 1 2 Cear statement of nu hypothesis e.g. there is no reationship / correation between ight intensity and rate of photosynthesis; 1 3 (a) Spearman Rank; 1 3 (b) Rate of photosynthesis measured at a number of ight intensities and this test determines if there is an association/correation between them; 1 4 Test statistic cacuated correcty; 1 Accept candidate s correct cacuation even if test is not appropriate 5 Compares the test statistic with the critica vaue at P = 0.05 / 5 % eve of probabiity; Correct statement concerning acceptance or rejection of nu 2 Use candidate s vaue of test statistic even if hypothesis; it is incorrect Tota 7 5

6 Bioogy - AQA GCE Unit 6T/P/Marking Guideines/2010 June series Section A Question Part Marking Guidance Mark Comments 6 Bubbes contain oxygen from photosynthesis/oxygen is a product of photosynthesis/oxygen is a product of photoysis; Higher rate of photosynthesis resuts in more bubbes being reeased; 2 7 a More bubbes reeased; Because increase in rate of photosynthesis/ower soubiity of oxygen/therma expansion of gas/(photosynthetic) enzymes work faster; 2 7 b Use of water-fied transparent container/sheet of gass/(cear) pastic/heat shied between pant and amp; Use of LED/ow votage bub/haogen bub/bub which does not give off heat; Use of arger test tube/voume of water; 1 max 8 Provides carbon dioxide/source of carbon for photosynthesis; Accept to act as a So carbon dioxide not imiting; 1 max buffer/maintain ph 9 Time needed for rate to adjust to new ight intensity / oxygen reeased from previous ight intensity sti present; 1 10 a Rate imited by ight intensity; Because rate of photosynthesis increases as ight intensity increases; Increase in ight intensity resuts in greater activation of chorophy / more eectrons reeased; So more photoysis / greater dissociation of water producing oxygen; 2 max 10 If described in terms of b Light intensity not imiting; Another factor is imiting; not enough rather than Carbon dioxide concentration/temperature/chorophy concentration imiting; 2 max imiting max 1 6

7 Bioogy - AQA GCE Unit 6T/P/Marking Guideines/2010 June series Section A continued Question Part Marking Guidance Mark Comments 11 Bubbes are the same size; Bubbes are oxygen/constant proportion of oxygen; A constant proportion of oxygen produced is reeased / oxygen produced does not dissove/oxygen produced is not used in respiration/rate of respiration constant; Bubbes do not stick to gass/apparatus; 2 max Tota marks for Section A 13 7

8 Bioogy - AQA GCE Unit 6T/P/Marking Guideines/2010 June series Section B Question Part Marking Guidance Mark Comments 12 To see if a difference in hours of sunshine was present/because it is necessary to monitor factors which cannot be controed; So that they coud eiminate this factor from affecting the yied (with/without extra carbon dioxide); Duration of ight infuences ength of time for photosynthesis/temperature in gasshouse; Higher photosynthesis resuts in higher yied/more carbohydrates/sugars/proteins produced; 2 max 13 Named factor; Expanation of why the factor is important; E.g. Density of panting; Competition for named resource; For named resource or accept nutrient but not Same variety of tomato; food Yied wi vary with different varieties/with different genotypes; or Water (appication); Water needed for expansion of fruit/maintain eaf turgidity/maintain stomata opening/repace water ost in transpiration/water used in photosynthesis; 2 14 a Yied increases by 0.6 kg m 2 (when extra carbon dioxide present); 1 14 b Temperature/ight intensity so coud be ower in these weeks (as temperature / ight insensity not fuy controed / monitored) (over period ); 1 8

9 19 b When/whether to start reease of the parasitic wasps; How many parasitic wasps to reease; To monitor effectiveness of method; Threshod popuation size beyond which they cause severe crop oss; 2 max 19 d Contro not immediate; Aways some pest present/pest not eiminated; 1 max Bioogy - AQA GCE Unit 6T/P/Marking Guideines/2010 June series Section B continued Question Part Marking Guidance Mark Comments 15 Two marks for correct answer of 50.6 %;; One mark for incorrect answer in which candidate has shown ceary that cacuation based on an increase / 0.42 and origina mass / Cost of suppying carbon dioxide; Price of (very eary) tomatoes; 2 17 Lowest price paid for tomatoes; Some carbon dioxide ost as windows open in summer; Litte/no mean increase in yied in summer; 2 max 18 Grow with extra carbon dioxide in one gasshouse and without carbon dioxide in other gasshouse at same time; So a environmenta conditions/ight and temperature same for experiment and contro; 2 19 a Bioogica contro; 1 19 c Ony catch fying whitefy / whitefy may not be eveny distributedj / don t Accept converse e.g. wi know what proportion of whitefy are caught; 1 not catch crawing young 9 Copyright 2010 AQA and its icensors. A rights reserved.

10 Bioogy - AQA GCE Unit 6T/P Marking Guideines 2010 June series Section B continued Question Part Marking Guidance Mark Comments 20 Traps with same surface area/stickiness/height above ground; Any two reevant factors Same cimatic conditions e.g. same wind speed, same temperature, same for two marks day; Do not aow weather Left for same ength of time/stated ength of time given; Large number of traps; If number stated this must Count number of whitefy trapped on both coours; east 10 Determine if there is a significant difference using a statistica test; 5 max Aow many, do not aow severa Tota marks for Section B 24 10

HBI6X/PM1. General Certificate of Education Advanced Level Examination June A2 Externally Marked Practical Assignment.

HBI6X/PM1. General Certificate of Education Advanced Level Examination June A2 Externally Marked Practical Assignment. Centre Number Surname Candidate Number For Examinerʼs Use Tota Task 1 Other Names Candidate Signature Genera Certificate of Education Advanced Leve Examination June 2013 Human Bioogy HBI6X/PM1 Unit 6X