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AQA Science Controlled assessment in GCSE

1. Sally Avalon Date 10th April ipiius As part of AQA s commitment to assist students AQA may make your CAU available on a strictly anonymous basis to teachers examining staff and students in paper form or electronically through the Internet or other means for the purpose of indicating a typical mark or for other educational purposes In the unlikely event that your CAU is made available for the purposes stated above you may object to this at any time and we will remove the work on reasonable notice If you have any concerns please contact cfg aqa org uk To see how AQA complies with the Data Protection Act 1988 please see our Privacy Statement at aqa org uk for certification from June 2014 onwards 29 Step 5 Analysing results 2 Hypothesis The survival and growth of microorganisms depends upon the concentration of disinfectant 1 a What were the variables in the investigation that you did 1 b 1 c 3 marks The independent variable was the concentration of disinfectant used The dependent variable was the number of bacteria that grew on each dish One control variable was the temperature of the incubator Did you repeat any of the measurements in your investigation Explain why you did or did not repeat any of your measurements Your explanation should include examples from your results 3 marks didn t need to repeat any of my measurements d
2. eyes and looks like hands well after the Red Cross skin Slips water so you practical just in case website for or falls if might forget Wear goggles at all information spilt to wash it times Know the first on 1st aid off aid for chemicals in the for eyes or on the skin If chemical your hands feel soapy burns wash with lots of water for certification from June 2014 onwards 59 Step 3 The effectiveness of antacid remedies Equipment Hazard Control measure Source of procedure information chemical used Calcium Low hazard Low it s Keep the lid on and Cleapss carbonate could used in lots don t shake container hazcards cause of everyday to keep the dust down coughing things like Any asthmatics should if breathed toothpaste have their inhaler on in them at all times Carrying Chemicals Medium Put the clamp and Own out the inthe eyes unless you stand down on the floor knowledge experiment or skin fill and to fill up the burette and practical could be use the so it is well below eye chemistry irritants burette very level Keep goggles on website carefully at all times Know the Use British 1st aid for chemicals in Red Cross eyes or on skin website for 1st aid for chemicals in eyes or on skin
3. For this paper you must have e results tables and charts or graphs from your investigation e a set of results obtained by other people e your Candidate Research Notes e the Secondary Data Sheet a pencil and ruler You may use a calculator Time allowed e 50 minutes Information Instructions e The marks for questions are shown in brackets Use black ink or black ball point pen e The maximum mark for Section 2 is 30 e Fill in the boxes at the top of this page e The maximum mark for the Controlled Assessment e Answer all questions in the spaces provided Unit is 50 Do not write outside the box around each page or on e You are reminded of the need for good English and blank pages clear presentation in your answers e Do all rough work in this book Cross through any work you do not want to be marked Details of additional assistance if any Has the candidate received any help or information from anyone other than the subject teacher s in the production of this work If the answer is yes give the details below or on a separate page Yes No x Did the candidate take an active part in the practical Yes x No B Teacher Declaration confirm that the candidate s work was conducted under the conditions laid out by the specification have authenticated the candidate s work and am satisfied that to the best of my knowledge the work produced is solely that of the candidate Signature of teacher
4. necessary to show the moderator reasons for the decisions Helpful hints candidates may improve their marks by carrying out another controlled assessment for the specification if more than one controlled assessment is completed submit the one with the highest mark for certification from June 2014 onwards 47 Administration teachers notes GCSE Science B Controlled Assessment The effectiveness of antacid remedies This task relates to Unit 2 context 3 4 1 2 Chemistry in action in the body Method Methods and techniques in the Controlled Assessment are not necessarily restricted to those mentioned in the specification Candidates should be encouraged to use appropriate technology when completing the task Candidates should be given the opportunity to carry out an investigation concerning the effectiveness of an antacid on stomach acid and must write a report on their findings Candidates should be given the opportunity to practice the techniques of titration before completing this investigation They should however plan and make decisions on equipment and readings to be taken for themselves Candidates should carry out some preliminary research concerning an application for their investigation They will need to decide on their research method which could include the use of books internet sources and surveys Candidates should bring the information they collect into the supervised sessions to use as par
5. This QWC would fall into the higher mark range Some hazards are identified There is no reference to burning risk when using flames or to other issues when working with bacteria such as the need for sterile agar Petri dishes The answer just falls within the higher category as a whole there are some omissions in several of the descriptors but the method could be followed by another candidate and would give valid results The candidate also indicates replication to improve the quality of results though does not refer to repeatability 7 marks for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 2 Reporting on the planning and research In your research you will have found other methods you could have used Outline one other method you could have used Explain why you decided not to use this method 3 marks could of dipped filter paper pieces into the disinfectant solution and put them on the agar jelly in the dish with bacteria and then put it in the incubator didn t do this because wouldnt have got much disinfectant on the filter paper pieces so my results wouldn t be very good and it would be hard measuring the bacteria with a ruler Make sure that you hand in your Candidate Research Notes and your blank table for the results with this paper You will be awarded up to two marks for your table Do not write outside the box Comments Q4 An alte
6. and P3 may be used for Further Additional Science three controlled assessments for Science B one for each unit for certification from June 2014 onwards 5 Step by step guides These step by step instructions are a guide for completing controlled assessment for e Science A e Additional Science e Biology e Chemistry e Physics e Further Additional Science To get started choose an Investigative Skills Assignment ISA from the teachers notes on e AQA Teachers should then e explain to the candidates the context of the investigation e explain to the candidates the nature of the problem to be investigated e provide the hypothesis supplied by AQA Science A only e follow the six steps below on completing an ISA Step 1 Planning limited control e Candidates are given the opportunity to carry out an investigation e They need to research and identify one or two methods that could be used depending on the ISA Helpful hints e candidates may use technology such as the internet or CD ROMs for their research textbooks or any other appropriate sources of information e candidates should research the context of the investigation e candidates should research a method or methods for the experiment This should include a risk assessment e candidates can create one A4 side of their own research notes to use in step 2 and step 5 This should be done on the candidate research notes sheet provide
7. graph to support the comment comment comment A clear advantage of A clear advantage of using Ger off or a using Ger off and clear disadvantage a clear disadvantage of using Ger off is of using Ger off is stated stated Additional Examples of advantages include all Listeria will be killed at 90 concentration or guidance All E coli probably killed at 90 Examples of disadvantages include Staphylococcus will not all be killed or has not been tested on other bacteria need to consider cost effectiveness or need to compare effectiveness with currently used disinfectants or use depends on nature of infection being treated Section 2 0 marks 1 mark 2 marks 3 marks Q No 3 No Results from the Results from the Results from the creditworthy investigation or investigation or investigation or response an idea from the an idea from the an idea from the research has been research has been research has been related to the related to the related to the context context context There is a simple There is a detailed explanation of how explanation of how the results or idea the results or idea can be applied and can be applied in used in the context the context Additional The candidate could attempt to explain e g how manufacturers of disinfectants guidance or homeowners could work out the optimum concentration of disinfectant to use at home for certification
8. 2014 onwards 73 Step 6 Analysing data O marks Level 1 Level 2 Level 3 A conclusion has been The candidate has tried to The conclusions do not given 1 mark relate the conclusion relate directly to their to the data but has got primary data as they confused in their use of are confused on how to data The example they use the data There are have given using data some correct conclusions does not support their concerning the secondary conclusion even though data but no further their conclusion is correct secondary data eg group They have compared their data has been used results with the secondary There is no evidence of a data 1 mark and have comprehensive scientific suggested repeating the understanding The anomalous result to candidate should discuss improve reliability and that the acid is neutralised have given simple by the calcium carbonate suggestions to improve and this is why less alkali validity 1 mark is needed when more calcium carbonate is used This should then relate to the initial question of how effective antacids are on stomach acid Total 3 6 marks Step 7 Evaluating the practical activity O marks Level 1 Level 2 Level 3 An evaluation has been The effectiveness of the Strengths and weaknesses carried out 1 mark and methods has been have been described improvements have been evaluated 1 mark 1 mark and justified suggested 1 mark The improvements are
9. Even if a candidate does not go on to carry out his or her plan for the experiment that candidate may still be awarded up to maximum marks for the written plan in section 1 of the ISA In a unit 2 or unit 3 ISA it may be necessary to give the candidate a different hypothesis This is because the new method may not be capable of testing the candidate s original hypothesis GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT ISA explanation sheet AQA ISA Explanation Sheet to accompany each ISA You will need to fill in more than one of these sheets if different students have carried out different methods Centre Date Practical Number 9 8 7 6 5 Carried Out ISA Code PUI x ISA Title Name of r Teacher G Fisky Independent Dependent variable variable Did you make any changes to the suggested method YES No If YES give details of any changes you made to the suggested method the equipment chemicals etc for this investigation 30 candidates in the group produced about a dozen different methods Which considered unmanageable So we used the AQA method PUI x Domestic hot water tanks Any other Information Teacher Signature Please attach any experimental worksheet or outline used by the candidates to carry out the investigation if available G Fisky for certification from June 2014 onwards 23 Step 3 Pr
10. added we will use less sodium hydroxide to neutralise the acid because the calcium carbonate reacts with the hydrochloric acid to give carbon dioxide calcium chloride and water The water will dilute the remaining acid so less alkali is needed to neutralise it for certification from June 2014 onwards 57 Step 3 The effectiveness of antacid remedies 3 ASSESSING AND MANAGING RISK Equipment Hazard Risk Control measure Source of procedure information chemical used Glassware You could Medium risk Visually check for Own to anyone cracks or chips before knowledge using them picking up Keep away Use British They are very from edge of bench Red Cross easy to break Know the 1st aid for website for cuts 1st aid for Electronic Electric Low as they Visually check wires cuts Own balance shock are designed and plug have intact knowledge to be safe to insulation before Use British use in labs plugging in Ensure that Red Cross and use a low bench is dry and no website voltage taps are used nearby for 1st aid Know the 1st aid for for electric Universal Flammable Medium risk electric shock No Bunsen flames on shock Cleapss indicator and c
11. again use their candidate research notes that they made during their research Candidates who have been given a method sheet for a new method may be allowed to use this when answering section 2 for certification from June 2014 onwards Key points Secondary data is given in section 2 to which candidates will need to refer Therefore candidates should be familiar with using this type of stimulus material and have the necessary experience in order to evaluate the data given GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 5 Analysing results Centre 9 18 T 6 5 Candidate 1 2 3 4 For Teacher s Use Number Number Surname Flude eee Jay Sue Notice to Candidate The work you submit for assessment must be your own If you copy from someone F else or allow another candidate to copy from you or if you cheat in any other way you may be disqualified Section Candidate Declaration have read and understood the Notice to Candidate and can confirm that have produced the attached work without assistance other than that which is acceptable under the Section 1 scheme of assessment 20 Candidate Date th i Section 2 Signature Jay S Flude 7 April P A A rj General Certificate of Secondary Education June 20yy Science A Specimen SCA4P BU1 X Controlled Assessment ISA BU1 x Microorganisms Section 2 For moderation in May 20yy
12. candidates to investigate e lead a discussion with the candidates to outline the technique that is to be used This might include demonstrating the technique and illustrating the variety of equipment available Candidates may need to practice the technique e follow the steps below on completing a controlled assessment Step 1 Planning and research limited control e Candidates need to research the context of the investigation to give an application for it e They need to identify the method they are going to use e They need to identify the hazards and risks associated with their investigation Helpful hints e candidates may use technology such as the internet or CD ROMs for their research textbooks journals or any other appropriate sources of information e candidates should decide for themselves factors such as the independent variable the range interval and number of repeat readings they should take e candidates may bring the information they collect at this stage into the supervised sessions to use in preparing their final report e the planning stage should take one to two lessons including the high control session used for the write up for certification from June 2014 onwards 45 Step 2 Reporting on the planning and research high control Candidates work on their own to write their introduction to the investigation prepare their plan and compile the risk assessment Candidates may use the
13. come across such a web site then you should e notify AQA so that we may ask that the website be taken down e not permit your students to use the website for their research Key points Collectively candidates could produce a huge variety of methods to perform their practical work If the teacher decides that the method produced by the candidate s is unworkable unsafe or unmanageable then the teacher may provide a method AQA will supply a method that may be used in such circumstances which teachers can adapt to their own programme of study Alternatively teachers may provide their own method If the teacher provides the candidate with a different method the worksheet for this method may be given to the candidate for use with section 2 of the ISA Teachers should always complete an ISA explanation sheet The candidate s research notes sheet of which an example can be found on the following page will be used by the candidate for both of the written sections of the ISA for certification from June 2014 onwards 13 Step 1 Planning A A Fd Controlled Assessment Candidate Research Notes For use with GCSE Science A Route 1 4405 GCSE Science A Route 2 4406 Additional Science Route 1 4408 Additional Science Route 2 4409 Further Additional Science 4410 Biology 4401 Chemistry 4402 Physics 4403 sca4p X As4P BL4P CH4P PH4
14. in the boxes at the top of this page e The maximum mark for the Controlled Assessment e Answer all questions in the spaces provided Unit is 50 Do not write outside the box around each page or on You are reminded of the need for good English and clear presentation in your answers blank pages Do all rough work in this book Cross through any work you do not want to be marked Details of additional assistance if any Has the candidate received any help or information from anyone other than the subject teacher s in the production of this work If the answer is yes give the details below or on a separate page Yes No x Teacher Declaration confirm that the candidate s work was conducted under the conditions laid out by the specification have authenticated the candidate s work and am satisfied that to the best of my knowledge the work produced is solely that of the candidate Signature of teacher Sally Avalon Date As part of AQA s commitment to assist students AQA may make your CAU available on a strictly anonymous basis to teachers examining staff and students in paper form or electronically through the Internet or other means for the purpose of indicating a typical mark or for other educational purposes In the unlikely event that your CAU is made available for the purposes stated above you may object to this at any time and we will remove the work on re
15. marks 3 marks Q No 1 a No Any one variable Any two variables All three variables creditworthy correctly identified correctly identified correctly identified response Additional The independent is the concentration of disinfectant used guidance Examples of dependent variables are the number of colonies of bacteria that grow or the cloudiness of nutrient broth Examples of control variables are the volume of disinfectant used the temperature of incubation or the time of incubation Section 2 0 marks 1 mark 2 marks 3 marks Q No 1 b No There is a correct There is a correct There is a correct creditworthy statement regarding statement regarding statement regarding response whether or not any whether or not any whether or not any measurements were measurements were measurements were repeated repeated repeated There is mention There is reference There is reference of the presence to either anomalous to either anomalous or absence of results or to results or to anomalous results systematic or systematic or or minor variations random errors with random errors with reference to their reference to their own results own results and the effects that these would cause Additional If the candidate answers Yes they may refer to clearly anomalous results that need guidance repeating or to the fact that not all the points lie comfortably on a line of best fit random errors or to a systematic error therefore needing
16. new controlled assessment process The controlled assessment process Controlled assessment consists of three stages Stage 1 Task setting All controlled assessments are set by AQA and will be available for submission in the June examination series of each year Stage 2 Task taking A description of how candidates carry out the tasks and the conditions under which assessment takes place is illustrated below Stages of task Level of control Description Candidates can work unsupervised and outside of the classroom Candidates will carry out practical work under supervision Limited control limited supervision Research and data collection Candidates work individually to complete their reports under conditions of high control at the centre and under direct formal supervision Writing analysis High level of evaluation and control formal review supervision Stage 3 Task marking Tasks are internally marked using the mark guidance supplied by AQA and externally moderated by an AQA moderator 4 for certification from June 2014 onwards Levels of control Each of the three stages has a level of control to ensure reliability and authenticity and to make assessments more manageable for teachers and candidates Levels of control for GCSE Science are explained below Limited control with low level limited supervision e Candidates can complete work without dire
17. onwards 77 Helpful websites and contact Information Free services e AQA e AQA gives teachers access to useful resources such as Exampro Extra Online and enhanced results analysis ERA To find out more about Exampro Extra Online register for ERA at https extranet aga org uk Teacher Support meetings Details of the full range of our teacher support meetings are available on our website at aga org uk professional develooment Speak to your subject team You can talk directly to the GCSE sciences subject team about all our GCSE sciences specifications on 01483 477 756 or email science gcse aqa org uk For the latest information Find out more including the latest news support and downloadable resources at aga org uk ry E a Fs J 74 i 4 u 4 78 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT for certification from June 2014 onwards 79 AQA aqa org uk Copyright 2013 AQA and its licensors All rights reserved AQA Education AQA is a registered charity registered charity number 1073334 and a company limited by guarantee registered in England and Wales company number 3644723 Registered address AQA Devas Street Manchester M15 6EX December 2013 AQA SCI 0061 13
18. specification and a more detailed version with individual mark allocations can be found in Secure Key Materials in e AQA https extranet aqa org uk Key points Candidates should be familiar with using secondary data and have the necessary experience in order to evaluate the data given Key points e Teacher online standardisation TOLS is available on e AQA Find out more about at aga org uk about us what we do products and services teacher online standardisation e Each centre is assigned a Controlled Assessment Adviser who will be able to give direct support on all aspects of the controlled assessments Contact details for your adviser can be found on TOLS or by contacting the GCSE Science subject team at science gcse aqa org uk for certification from June 2014 onwards 53 Step 1 The effectiveness of antacid remedies 1 RESEARCH I m going to investigate how effective antacids are on stomach acid Sometimes people take antacids if they get indigestion or heartburn On www bbc co uk health it says that if you get indigestion you might feel pain in your stomach or think you re having a heart attack You might feel bloated or get wind or nausea Sometimes excess acid is linked with ulcers and drugs like aspirin can make it worse Antacids are alkalis so neutralise the acid When chemists make new antacids they have to be tested to check the
19. that this has already been marked by the teacher Alternatively the teacher may provide a blank table for the results e if the table produced by the candidate is inadequate in which case the candidate would not be able to score full marks for producing a table e if the candidate carries out an investigation from a method provided by the teacher or the teacher prefers that the candidate use a particular format in which case the candidate would be able to score full marks for producing their own table Stage 4 Processing primary data High control For this part of the investigation candidates must work individually under direct supervision Candidates should be given back their table of results or a table containing the pooled results of the class and asked to display these on a bar chart or line graph Candidates must decide for themselves which format is the more appropriate for any particular investigation Candidates may use appropriate technology to do this e g a graph drawing program on a computer If a candidate chooses to use a computer this must be done under the direct supervision of the teacher and must be printed straight away Candidates should not be allowed to take their results and chart or graph away the teacher must collect them at the end of the lesson Stage 5 Analysing results High control For this part of the investigation candidates must work individually under direct supervision AQA will provide a
20. AQA TAN GCSE SCIENCES Guidance on controlled assessment Contents Introduction to controlled assessment Step by step guide for e Science A e Additional Science e Biology e Chemistry e Physics e Further Additional Science Controlled assessment in detail e Step 1 Planning e Step 2 Reporting on the planning and research e Step 3 Practical work e Step 4 Processing primary data e Step 5 Analysing results e Step 6 Marking the ISA Step by step guide for e Science B Controlled assessment in detail e Step 1 Planning and research e Step 2 Reporting on the planning and research e Step 3 Practical work e Step 4 Data processing analysis and evaluation e Step 5 Marking the controlled assessment Administration FAQs for certification from June 2014 onwards 03 06 13 45 51 Ta H GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Introduction In this guide we re providing detailed support and advice on how to prepare sit and assess controlled assessment for the following AQA GCSE Science specifications e Science A e Additional Science e Biology e Chemistry e Physics e Science B e Further Additional Science To help you understand the changes we ve provided step by step instructions about the controlled assessment process and outlined what is expected of your candidates At each step you will see candidate exemplar material to clearly show the
21. Carbon Suffocation Very low as Keep the lab well Own dioxide only small ventilated by opening _ knowledge amounts will up the windows and be produced Cleapss by the hazcards reaction 60 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 3 The effectiveness of antacid remedies Equipment Hazard Control measure Source of procedure information chemical used hydrochloric Irritant Medium as it Clear up any spillages Cleapss acid 0 1M can can be spilt immediately using paper hazcards damage very easily and towels Wash hands well Use British the skin looks like after the practical justin Red Cross and eyes water so you case Wear goggles at all website for Slips or might forget times Know the first aid information falls if to wash it for chemicals in the eyes on 1st aid spilt off or on the skin Make for sure there s no metals chemical left lying around as acid burns reacts with them Irritant Medium as it Clear up any spillages Cleapss can can be spilt immediately using paper hazcards damage very easily and towels Wash hands well Use British eyes and looks like after the practical justin Red Cross skin Slips water so you case Wear goggles at all website for or falls if mi
22. ESSMENT 2 c ACKNOWLEDGEMENT OF COPYRIGHT HOLDERS AND PUBLISHERS Look at Case Study 4 A hospital worker who saw the results advised The hospital can use Ger off at 90 concentration to make sure most bacteria are killed Do you agree with this advice Explain your answer 3 marks s l don t think it would be a good idea because even at 100 Ger off doesn t kill many staphylococcus and staphylococcus is a common bacteria that you get in hospitals But it would be good at killing Listeria bacteria and nearly all the E coli 3 Hospitals need to kill MRSA and the new disinfectant hasn t been tried on MRSA How could the results from your investigation be useful in the context that you have researched question Comments 2 c The candidate states that the advice is not supported and explains the reason for this The candidate states an advantage of Ger off and identifies further trials that should be done with Ger off marks Comments Q3 You may use information from your Candidate Research Notes to help you to answer this e 3 marks I found out that it is important to use strong disinfectant to kill all the bacteria Most disinfectant bottles say kills 99 of all known bacteria but there are still lots we don t know about so we don t know if they are killed or not If we add water to disinfectant it isn t so useful at killing bacteria and then
23. P Fas4P Centre number Centre name 98765 The Blue School Thetford Candidate s full name Candidate number Jay S Flude 1234 Investigation Title Microorganisms specimen ISA number BU1 X The only notes the candidate takes into the Controlled Assessment are to be written in the spaces on the back of this sheet This sheet should be given to the teacher for checking before it is used in Section 1 of the ISA When Section 1 of the ISA has been completed this sheet should be retained by the teacher for subsequent use with Section 2 When Section 2 of the ISA has been completed this sheet should be stapled to it Declaration confirm that these are the only notes used in the Controlled Assessment S Sally Avalon Jay S Flude J Date 21 April This form can be downloaded from the Secure Key Materials area in eAQA SCIENCE CN To see how AQA complies with the Data Protection Act 1988 please see our Privacy Statement at aqa org uk Copyright 2013 AQA and its licensors All rights reserved The Assessment and Qualifications Alliance AQA is a company limited by guarantee registered in England and Wales company number 3644723 Registered address AQA Devas Street Manchester M15 6EX 14 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 1 Planning Hypothesis The survival and growth of microorganisms depends upon the concentration of disinfec
24. Secondary Data Sheet The candidates should also be given a table of results from other candidates in the class or the teacher s results Candidates should use the results of others to analyse the validity of their own results Candidates should be given Section 2 of the ISA They should also be given e their own table of results e a set of results obtained by other people e areminder of the context in which the investigation was set e their own chart or graph e the Secondary Data Sheet supplied by AQA e their own Candidate Research Notes The teacher should have recorded the marks for each candidate s table and graph chart before these are given back This will ensure that a candidate cannot gain an unfair advantage by making any alterations to them at this stage Any candidate who does not take part in the practical work cannot score any marks for Section 2 of the ISA for certification from June 2014 onwards 11 Administration teachers notes Section 2 will require candidates to analyse their own results draw a conclusion match their achieved results to the original hypothesis that was given to them analyse the validity of their own results by using the results of others evaluate the method of collection and the quality of the resulting data establish the validity of their results by comparing their results with those of others analyse further secondary data drawn from the same topic area as their or
25. actical work A A rj Controlled Assessment Method Sheet Science A BU1 x Microorganisms Specimen This method could be used to investigate the following hypothesis The survival and growth of microorganisms depends upon the concentration of disinfectant You will need to prepare a table for the results Equipment Nutrient broth pre inoculated with safe bacteria labelled safe bacteria 5 test tubes Syringes or other means of measuring volumes of 0 5cm and 5cm 5 sterile nutrient agar plates Incubator at 25 C Disinfectant solution diluted to double normal working strength refer to label on bottle used Means of labelling tubes and agar plates Inoculating loop Bunsen burner Method Sa 2 SNe oP aN Ss 12 Label 5 test tubes 1 to 5 Put 10cm of the disinfectant into test tube 1 Remove 5cm from test tube 1 into test tube 2 Add a further 5cm of water to test tube 2 Remove 5cm from test tube 2 into test tube 3 Add a further 5cm of water to test tube 3 Repeat this process to make test tubes 4 and 5 Remove 5cm of solution from test tube 5 and discard it Add 0 5cm of safe bacteria to each of the five test tubes Shake gently to mix them Using sterile techniques spread samples from each test tube onto the agar in separate prepared Petri dishes of sterile nutrient agar Label the dish
26. ake sure your candidates know key words such as hypothesis and variables for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 2 Reporting on the planning and research Centre Candidate For Teacher s Use Number 9 8 7 6 5 Number 1 2 3 4 Surname Flude Other Jay Sue Names Notice to Candidate The work you submit for assessment must be your own If you copy from someone Section Mark else or allow another candidate to copy from you or if you cheat in any other way you may be disqualified Candidate Declaration have read and understood the Notice to Candidate and can confirm that Section 1 have produced the attached work without assistance other than that which is acceptable under the 20 scheme of assessment Candidate Date k th Section 2 Signature Jay S Flude April 4 2011 30 TOTAL max 50 rj General Certificate of Secondary Education AQ A ld June 20yy Science A Specimen SCA4P BU1 X Controlled Assessment ISA BU1 x Microorganisms Section 1 For moderation in May 20yy You will need e Your Candidate Research notes e A pencil and a ruler You may use a calculator Time allowed e 45 minutes Information Instructions The marks for questions are shown in brackets e Use black ink or black ball point pen e The maximum mark for Section 1 is 20 e Fill
27. asonable notice If you have any concerns please contact cfg aqa org uk To see how AQA complies with the Data Protection Act 1988 please see our Privacy Statement at aga org uk for certification from June 2014 onwards 17 Step 2 Reporting on the planning and research Hypothesis The survival and growth of microorganisms depends upon the concentration of disinfectant Think about the research that you did to find out how to test this hypothesis Identify two sources that you used for your research 1 AQA Science by Jim Breithaupt Ann Fullick Patrick Fullick published by Nelson Thornes 2 Internet http www selah k12 wa us SOAR SciProj2003 CharleyW html Compare the usefulness of the two sources 3 marks The internet was the best because it gave me some good ideas about how to do the investigation had to change the independent variable from type of disinfectant in the one on the internet to concentration of disinfectant for my experiment The book was not so good because it only talked about killing bacteria and antibiotics and didn t give a method In this investigation you will need to control some variables Write down one variable that will need to be controlled will need to find out how much of the bacteria to Describe briefly how a preliminary investigation could help you to find a suitable value for the control variable You should explain how the results of this preli
28. ating each experiment until got 3 repeats all within 0 5ml of each other To make my data more valid should have found out more about antacids A E and tried to use the same amount of chemicals in my experiment so could compare my results with those more or could have borrowed some results from someone else in the class to check them The most effective antacid in the table was also antacid B as only 12 65ml of sodium hydroxide was used to neutralise the dilute acid whereas antacid E needed 24 6ml for certification from June 2014 onwards 67 Step 7 The effectiveness of antacid remedies 7 EVALUATING THE PRACTICAL ACTIVITY Most of my results were good apart from the 1st attempt with 0 07g which was too high should have repeated this one again think the rest of my results are good as all of the points on the graph are close to the line that did Strengths Weaknesses Working safely and in an used powdered marble instead organised way of pure calcium carbonate Didn t have to ask for lots of put the sodium hydroxide in the help in the experiment burette which blocked up the tap a bit did lots of repeats It was hard to tell when the acid was neutralised because the colour change was hard to see tidied up my working area It was hard to mix the co
29. bacteria Do not give full credit to a candidate who describes how to do the entire investigation at this stage 36 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Section 1 In this question candidates are required to produce extended written material in English and will be assessed on the quality of their written communication as well as the standard of the scientific response Candidates will be required to use good English organise information clearly and use specialist terms where appropriate In order to attain a mark within a certain level both the science and the QWC must be considered Read through the whole of the candidate s answer and use the marking guidelines below to arrive at a best fit mark as candidates may meet some criteria but not others in a mark range 0 marks 1 2 or 3 marks 4 5 or 6 marks 7 8 or 9 marks Q No 3 No Some of the Most of the Most of the creditworthy necessary necessary necessary response equipment is stated equipment is stated equipment is stated The method The method The method described is weak described will described will enable but shows some enable valid results valid results to be understanding of to be collected collected the sequence of an The measurements The measurements investigation to be made are to be made are The measurements stated At least one stated Control to be made are control variable is varia
30. bles are clearly stated given identified with An appropriate Any significant details of how they hazard is hazards are will be monitored or identified but the identified together controlled corresponding risk with a corresponding Any significant assessment and control measure but hazards are control measure is the risk assessment identified weak or absent is weak or absent together with an The answer is poorly The answer has assessment of the organised with some structure and associated risks almost no specialist organisation use of and corresponding terms and little orno specialist terms has control measures detail given been attempted but The answer is The answer shows not always correctly coherent and written very weak spelling and some detail is in an organised punctuation and given logical sequence grammar The answer shows containing a range reasonable spelling of relevant specialist punctuation and terms used correctly grammar although The answer shows there may still be almost faultless some errors spelling punctuation and grammar Additional Typical hazards with associated risk reduction might include once incubated the plates guidance should not be opened to prevent possible spread of pathogens that may have grown It may be possible to credit a clearly labelled diagram for some of the marks for certification from June 2014 onwards 37 Section 1 Q No 4 Additional guidance 0 ma
31. boratory It is the responsibility of the centre to be aware of any health and safety implications of the investigation and ensure that a risk assessment for the practical is carried out Teachers should remind candidates about safe working when carrying out laboratory procedures Analysing secondary data As part of the task candidates are required to verify their data by comparing it with secondary data This data could be the results obtained by other groups within the class and or results for the investigation that have been obtained by the teacher or technician before the candidates do the practical themselves Candidates should also use the data given in the Notes for Candidates Stage 1 Planning and research The teacher should lead a discussion with the candidates to outline the technique that is to be used This might include demonstrating the technique and illustrating the variety of equipment available Candidates should be shown the technique to be used and should be given the opportunity to have hands on experience of the technique Candidates should then be left to themselves to decide factors such as the independent variable to be investigated the range interval and number of repeat readings they should take At the end of the planning session candidates must work on their own under direct supervision to write their plan and risk assessment for the practical Teachers must collect all work at the end of the session and k
32. ct supervision outside of the classroom This work will not contribute directly to assessable outcomes e Candidates can access resources and work in groups e Teachers can provide limited guidance to candidates High level of control formal supervision e Candidates must be in direct sight of the teacher at all times e Use of resources is tightly prescribed e Candidates must not communicate with each other e Candidates must complete all work independently e No assistance can be given to candidates GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Getting started For AQA GCSE Science A Additional Science Biology Chemistry Physics and Further Additional Science the controlled assessment takes the form of an Investigative Skills Assignment ISA For Science B the controlled assessment Using Practical and Investigative Skills takes the form of a contextualised investigation based on a unit from the specification To get started you need to 1 Read the teachers notes Each year AQA will issue centres with a set of teachers notes on e AQA These will contain details of the experiments that may be used for the controlled assessment for that year Under the new criteria each controlled assessment is only operational for a 12 month period However AQA will release the teachers notes and other related material one year before its operational period This should enable more flexibili
33. ct all work in at the end of the session and keep it securely for marking and submission with the final moderation The teacher should not return work to the candidate The teacher may provide a method after the candidate has produced their own plan if the candidate s plan is unworkable unsafe or unmanageable in the laboratory For plans that are otherwise good but unworkable for a good reason ie logistical candidates should not lose any marks However where the plan is dangerous or unworkable from a scientific perspective this will be reflected in the marking Step 3 Practical work 52 Candidates perform the practical investigation Candidates may use the method that they have planned If the teacher decides that the method produced by the candidate s is unworkable unsafe or unmanageable then the teacher may provide a method There is no specified time limit for the practical work although it is anticipated that most experiments can be completed within a 1 hour lesson If necessary however the experiment may be continued over a number of lessons It may be necessary for the teacher to pool the results of the class This is so that each candidate may be allowed to see the results of others in order to evaluate their own work and form a conclusion Teachers may also choose to carry out the investigation themselves to provide another set of data for the candidates to analyse and evaluate for certification from J
34. d by AQA 6 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 2 Reporting on the planning research high control Candidates will need to produce a blank table ready for the results of the investigation This may be produced at the same time as the candidates are answering section 1 of the ISA or at any other convenient time prior to the practical work being carried out Candidates will be given section 1 of the ISA to answer They will need to work on their own and under controlled conditions to answer it Candidates can use their own candidate research notes Section 1 is a 45 minute written test with 20 marks available Helpful hints before undertaking section 1 make sure your candidates know e the context of the investigation and how it might be applied in real life e key words such as hypothesis e what variables in an investigation they need to consider and manage e different ways to test a hypothesis e how to write a detailed plan of a chosen method e possible hazards and risks and how to minimise them e different tables that are used to record results Step 3 Practical work limited control Candidates perform the practical experiment either individually or in groups Candidates may depending on circumstances use the method that they have planned or a method provided either by the teacher or by AQA Helpful hints e if ateac
35. e followed by another person 1 mark The variables are given and a possible relationship between the variables is shown 1 mark The candidate has recognised that the investigation is a back titration However the candidate has shown a lack of understanding when stating that the water produced will dilute the acid causing less alkali to be needed to neutralise it There are some steps that are unclear in the plan Step 6 could be improved by stating that the alkali should be added dropwise while swirling the conical flask The candidate has also not explained that titrations should be repeated until there is concordance in the results If this was all present then the Level 3 planning mark could be awarded Although the relationship between the variables is given it is not presented as a quantitative relationship The candidate should suggest for example what might happen when the amount of calcium carbonate is doubled Also the understanding of why the amount of alkali needed decreases when the amount of calcium carbonate is added increases is confusing and so the Level 3 mark cannot be awarded here Total 4 6 marks for certification from June 2014 onwards 71 Step 3 Assessing and managing risk 0 marks Level 1 Level 2 Level 3 and safety practices 1 mark A risk assessment has been completed 1 mark with references to health The hazards 1 mark and associa
36. e to others in their group for data analysis and evaluation Candidates should use the results of others possibly other groups in their class or teacher obtained results and the secondary data given in the Notes for Candidates to analyse the validity of their own results Stage 3 Data processing analysis and evaluation For this part of the investigation candidates must work on their own under direct supervision to write up their findings analyse their own and the secondary data and present their evaluations and conclusions The data given in the Notes for Candidates are based on taking 0 125g of calcium carbonate adding 50 cm of 0 1 M HCl and titrating the excess with 0 1 M NaOH 50 for certification from June 2014 onwards Controlled assessment GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT In detail Science B Step 1 Planning and research The discussion session Methods and techniques in the controlled assessment are not necessarily restricted to those mentioned in the specification The teacher should lead a discussion with the candidates to outline the technique that is to be used This might include demonstrating the technique and illustrating the variety of equipment available Candidates should be shown the technique to be used and should be given the opportunity to have hands on experience of the technique Candidates should then be left to themselves to decide factors such as the independe
37. eep it securely for marking and submission with the final report for moderation Candidates also need to carry out research into an application of the investigation they are carrying out This research could take different forms such as internet searches book and journal searches or questionnaires and surveys Candidates should decide for themselves an appropriate method of research for their investigation for certification from June 2014 onwards 49 Administration teachers notes Stage 2 Practical work For this part of the investigation candidates may work individually or in groups The teacher may provide a method after the candidate has produced their own plan if the candidate s plan is unworkable unsafe or unmanageable in the laboratory For plans that are otherwise good but unworkable for a good reason ie logistical candidates should not lose any marks However where the plan is dangerous or unworkable from a scientific perspective this will be reflected in the marking The method suggested above could be used but this should not preclude centres from adapting the method to suit their own needs Candidates may be given instructions of a general nature but these should not be so prescriptive as to preclude candidates from making their own decisions Each candidate must contribute to the collection of data Once the candidates have completed their investigation their results should be made availabl
38. er of a eea a or bacteria that grew ee bacteria that grew in the dish in the dish 0 126 0 246 20 88 10 258 40 32 20 222 60 10 30 187 80 4 40 156 100 0 50 122 60 65 70 29 80 13 90 10 100 3 Turn over gt 26 for certification from June 2014 onwards Do not write outside the o 27 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Science teacher Miss Avalon Jay S Flude Form 10P Microorganisms ISA Step 4 Processing primary data Saar a aa HHE SANEREN Spee eee a CERE a 3 a ean CESSER AE i Fi HERRERA EPEDEONKEAHMENRA H EREE EEF EE E COROZEZNARHERAANANENEREAN af Epi LEF HERH A t ES MERMA H ee Sere ELE E a TH a a EEEE p A e E TaLina n SEES EE eee E E drman EM His At aa 3 EEE pe ee weer PERNU GEEe PSE el peaa E E aeaee e E EEH E p pua Turn over gt Step 5 Analysing results Section 2 of the ISA high control 28 Section 2 will include questions concerning conclusions and evaluation 50 minutes are allowed for this section but again the usual access arrangement rules will apply AQA will supply a data sheet containing a number of case studies for candidates to use in section 2 of the ISA Section 2 will also include a question asking candidates to relate the findings from the investigation to the context they were given Candidates may
39. es and then place them in the incubator at 25 C for 2 3 days After 2 3 days count and record the number of colonies of bacteria on each agar plate Copyright 2013 AQA and its licensors All rights reserved 24 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 4 Processing primary data Drawing the graph or bar chart high control e Candidates will be required to draw a graph or bar chart of their results e Examples of marking guidelines for the graph bar chart can be found towards the end of this document Candidates may be awarded up to 4 marks for an appropriate bar chart or line graph Key points Computers and information technology can be used to generate the line graph or bar chart but this must be done under direct supervision of the teacher for certification from June 2014 onwards 25 Step 4 Processing primary data Results Table Do not write outside the box Jay S Flude Teacher Miss Avalon Strength of Amount of Amount of Number of Number of Average disinfectant water used disinfectant bacteria that bacteria that number cm used cm grewinthe grew inthe dish dish 0 5 0 56 68 62 20 4 1 58 42 50 40 3 2 29 33 31 60 2 3 32 22 27 80 1 4 5 12 9 100 0 5 2 0 1 Group 1 results Group 3 results 6 P Number of 7 Numb
40. et of results from a laboratory technician or the teacher Risk Assessment It is the responsibility of the centre to ensure that a risk assessment is carried out for certification from June 2014 onwards 9 Administration teachers notes Stage 1 Planning Limited control Teachers should provide the candidates with a Candidate Research Notes Form with the hypothesis and context written on them Candidates should be given the opportunity to plan an investigation to test the hypothesis The investigation should be set in a context by the centre Examples of suitable contexts could include the need for sterile equipment in hospitals or the use of hand cleaning gels Whichever context is chosen the teacher must take care to present it in such a way that it does not limit the candidates choice of method for the investigation Candidates should then independently research an appropriate plan to test the hypothesis and decide for themselves factors such as the range interval and number of repeat readings that they should take and the variables that need to be controlled They should use at least two sources for this research Candidates will need to undertake independent research to identify two methods that could be used During this time they may make up to one A4 side of their own Candidate Research Notes for use during Section 1 and Section 2 of the ISA The Candidate Research Notes sheet must be used for this pur
41. from June 2014 onwards 43 Graph or chart Answer Additional guidance Mark Q No 4 X axis suitable scales chosen and Scale should be such that the plots 1 labelled with quantity and units occupy at least one third of each axis Y axis suitable scales chosen and Accept axes reversed 1 labelled with quantity and units It may not always be necessary to show the origin Points or bars plotted correctly to Allow one plotting error out of each 1 within 1 mm 5 points bars plotted Suitable line drawn on graph or bars Allow error carried forward from 1 correctly labelled on bar chart incorrect points If wrong type of graph chart maximum 3 marks If the independent variable is e categoric a bar chart should be drawn e continuous a best fit line should be drawn NB If no line is possible because there is no correlation candidates should state this on the graph to gain the mark 44 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step by step guide Science B controlled assessment These step by step instructions are a guide for completing controlled assessment for Science B To get started choose a controlled assessment from the options on e AQA Teachers should then e put the task into a context that will be suitable for their candidates to understand the reason for the investigation e provide a hypothesis within the context for the
42. ght forget times Know the first aid information spilt to wash it for chemicals in the eyes on 1st aid off or on the skin If your for hands feel soapy wash chemical with lots of water burns for certification from June 2014 onwards 61 Step 4 The effectiveness of antacid remedies 4 COLLECTING DATA Mass of Volume of 0 1M sodium hydroxide added calcium to neutralise the remaining acid ml carbonate added to Rough 1st 2nd 3rd mean 50ml of titration attempt attempt attempt 0 1M hydrochloric acid g o 49 8 29 5 The 1st attempt using 0 07g gave a high result so wasn t used in my mean If had more time would have repeated this one again 62 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 5 The effectiveness of antacid remedies 5 PROCESSING DATA My graph is negatively proportional as it s a straight line It shows a negative correlation as it goes down It shows that as used more calcium carbonate the remaining hydrochloric acid was reduced so the volume of sodium hydroxide needed to neutralise it was also reduced calculated the moles of hydrochloric acid remaining by taking each mean titration and dividing it by 1000 and multiplying it by 0 1 My graph sho
43. guidelines will be available on e AQA To access e AQA register at https extranet aga org uk Security of ISA papers and marking guidelines When marking Section 1 and 2 of the ISA centres should treat them and the marking guidelines as secure assessment documents Therefore due care and regard needs to be taken if marking is done off site 34 for certification from June 2014 onwards Key points e Teacher online standardisation TOLS is available on e AQA Find out more about at aga org uk about us what we do products and services teacher online standardisation Each centre is assigned a Controlled Assessment Adviser who will be able to give direct support on all aspects of the controlled assessments Contact details for your adviser can be found on TOLS or by contacting the GCSE Science subject team at science gcse aqa org uk GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Marking guidelines Science ISA BU1 x Microorganisms Specimen For moderation in May 20yy Please mark in red ink Each part of each question must show some red ink to indicate that it has been seen Subtotals for each part of each question should be written in the right hand margin Enter the marks for section 1 and section 2 and the total mark on the front cover of the answer booklet for section 1 Fasten both sections together with the results table s and the graphical work and the candidate s resea
44. hat they are carrying out An example context is given below Biochemists working for pharmaceutical companies test a variety of medicines in order to find fast effective relief from heartburn or acid reflux Doctors may need to prescribe drugs to help patients with indigestion These medicines work by neutralising the excess acid within the stomach which helps break down food When developing new antacid remedies it is important for both scientific and commercial reasons to know 48 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Administration teachers notes what amount of antacid is best in neutralising particular acid conditions You are researching the effectiveness of an antacid preparation in neutralising an acid to compare the results with known antacids Suggested approaches Candidates could test either a known amount of an antacid compound or an appropriate commercial preparation 1 Candidates could add a known amount of hydrochloric acid volume and concentration to an antacid calcium carbonate Alternatively a commercial antacid preparation could be used If a commercial preparation is used it is recommended that one based on calcium carbonate is chosen 2 The excess acid can be found by titration against a standard sodium hydroxide solution By difference the amount of hydrochloric acid that reacted with the antacid can be calculated Working safely in the la
45. her decides that the method produced by the candidate s is unworkable unsafe or unmanageable then a method may be provided e AQA will supply a method that may be used in such circumstances or the teacher may provide one e after a candidate has submitted his or her own blank table teachers may supply a blank table in which candidates can record their results for certification from June 2014 onwards 7 Step 4 Processing primary data high control e Candidates will be required to draw a graph or bar chart of their results Helpful hints e candidates may use a computer to create their graph but this must be done under the direct supervision of the teacher and must be printed straight away e for this part of the investigation candidates must work individually under direct supervision Step 5 Analysing results high control e Candidates will be given section 2 of the ISA which will include questions concerning conclusions and evaluation e Section 2 is a 50 minute written test with 30 marks available Helpful hints before undertaking section 2 make sure your candidates know e how to analyse results and draw conclusions e how to match results to a hypothesis e how to evaluate the method of collecting data and the quality of the results e how to analyse secondary data Step 6 Marking the ISA e Section 1 and section 2 of the ISA are marked internally using the marking guidelines su
46. ication from June 2014 onwards Total 7 8 marks Step 5 Processing data 0 marks Level 1 Level 2 Level 3 GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Patterns have been identified 1 mark The average mass for each titre has been calculated 1 mark A line graph has been drawn 1 mark The quantitative relationship between the variables has not been identified The candidate should describe for example what has happened when the amount of calcium carbonate is doubled The means have been calculated using appropriate significant figures for the data obtained 1 mark The candidate chose their own scales for the graph but was given guidance on drawing the data as a line graph 1 mark The candidate recognised they should not use the anomalous result for the 0 07g mass 1 mark The candidate has recognised that the line is negatively proportional However this doesn t clearly explain the relationship between the amount of calcium carbonate and the volume of alkali used to neutralise the acid so the Level 3 patterns mark is not awarded To be awarded the Level 3 calculation mark the candidate must show the mathematical formula they have used and give at least one worked example This is not present in this piece The candidate was given guidance on what sort of graph to draw so no marks are awarded here Total 6 10 marks for certification from June
47. id my experiment twice and the results are about the same each time expected that the second time would not give me the same results as the first time because when you take some of the solution you get different numbers of bacteria in it because it s not mixed evenly In your investigation you changed the concentration of disinfectant What was the range of this variable The range was from 100 fcne MOto OG EE If you had been able to use another value of this variable either within or outside this range what value would you have chosen Give a reason for your answer 3 marks I could have done 50 because it s in the middle and the 60 one is a bit off the line so doing 50 would have helped check it Comments Q1 a e Reference to bacteria rather than bacterial colonies is acceptable here e All three variables have been correctly identified 3 marks Comments Q1 b e There is a clear statement that repeats were not carried out There is no reference as to specific values from the results 2 marks Comments Q1 c e The correct range is quoted The values may be given in either order e A suitable value within the range has been given and the reason is acceptable 3 marks 30 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 5 Analysing results 1 d 1 e Do your results support the hypothe
48. iginal investigation relate their findings to the context set in the ISA 12 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Controlled assessment In detall Step 1 Planning The discussion session e After the teacher has chosen the controlled assessment task the teacher should then explain to candidates the nature of the problem to be investigated e Inunit 1 ISAs for Science A the teacher will give the candidates a hypothesis which has been supplied by AQA e In unit 2 and 3 ISAs candidates must supply their own hypothesis Research limited control e After the discussion session candidates should be told to research one or two possible methods of carrying out the investigation Whether it is one or two will depend on the particular ISA This could be done as a homework session e They will also need to research the context that has been set and any health and safety issues with the method s e They will be allowed to make notes on one side of A4 which they will take into section 1 and 2 of the ISA AQA will provide a candidate research notes sheet on e AQA which must be signed by both the candidate and the teacher e The use of web sites for research by students is permitted However there have been occasions when a third party has posted on the internet a copy or close version of the AQA suggested method from the Teachers Notes If you or your students
49. improvements are given 1 mark sensible and justified 1 mark Total 6 6 marks 74 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Administration Introduction Ae The controlled assessment papers will be available in May The Exams Officer may print out one copy of the ISA papers for the science department to use in preparation However these papers should be treated in the same way as for any other external exam paper and kept under strictly secure conditions The ISA papers should not be downloaded on to the centre s intranet Neither should any electronic copies be made Teachers notes are published on Secure Key Materials on e AQA so that teachers can incorporate the controlled assessment into their schemes of work The new specification controlled assessment can be used by the candidates as soon as they arrive in centres but they have only one opportunity for moderation Out of date ISAs will not be accepted for earlier or later moderation dates The candidates work must be held under secure conditions for the entire period Do not use the live controlled assessment tasks for practice purposes The use of past papers or parts of past papers is permitted but these should not be used in the context of a live ISA Candidates should be entered in February for moderation in the following June Teachers should attach the ISA to a specific s
50. information collected in their research to do this Writing up the plan should take no more than one or two lessons If it takes more than one lesson candidates work must be taken in and kept securely between lessons The completed plans should be kept securely and attached to the final report for marking Helpful hints before writing up the plan and risk assessment make sure your candidates know e ways of presenting sources of research e what variables in an investigation should be considered and managed e different ways to test a hypothesis e how to write a detailed plan of a chosen method e possible hazards the associated risks how to manage them and how to complete a risk assessment Step 3 Practical work limited control Candidates perform the practical experiment either individually or in groups Candidates may use the method they have planned or the method provided by the teacher Candidates may use ICT to collect their results where appropriate Helpful hints e if the candidate s own plan is unworkable unsafe or unmanageable in the laboratory the teacher may provide them with a method to use for collection of data 46 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 4 Data processing analysis and evaluation high control e Candidates work on their own to process and analyse their own data the secondary data given in the ca
51. ion for further explanation of the choices that can be made about when to certificate for each subject A candidate is only allowed to have one attempt at each ISA and this may only be submitted for moderation on one occasion Risk assessment It is the responsibility of the centre to ensure that a risk assessment is carried out for each investigation The practical work For this part of the investigation candidates may work individually or in groups It is advisable for teachers or technicians to carry out trial experiments Examples of teachers notes for the ISAs and for Science B are given in this guide The examples of marked work given in the Controlled assessment in detail sections are based on these teachers notes for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Frequently asked questions Question What does an ISA written test look like Answer Please refer to the documents supplied in the guide They are specimen papers accredited by Ofqual and are a representation of what the live controlled assessments will look like Question Do the new ISAs have different criteria for units 1 2 and 3 Answer Yes they do although the criteria are only slightly different in one respect As shown on page 6 AQA will supply a hypothesis for unit 1 ISAs whereas for units 2 and 3 candidates will be required to supply their own hypothesis Question Are there definition
52. minary investigation will help you to decide on the best value for the control variable 3 marks If use too much there will be bacteria all over the agar and won t be able to count it and if don t use enough the difference in the results won t be noticeable l could set up 10 petri dishes with agar in them Put 0 1cm3 of bacteria in one 0 2cm3 of bacteria in the next and so on up to 1 0cm3 of bacteria I d put them in the incubator for two days at 25C then look at them The best amount will be the one where the colonies are spread out just enough to Do not write outside the box Comments Q1 A website has been quoted and the reference to the book is sufficiently detailed with title and author The comparison of the two sources is just sufficient to enable the award of 3 marks 3 marks Comments Q2 A suitable control variable has been identified Values for the control variable are given However what 0 1 cm3 of bacteria would represent is unclear It is not clear what is meant by the last sentence A diagram may have helped On balance 2 marks is appropriate here 2 marks 18 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 2 Reporting on the planning and research Do not write 3 outside the box In this question you will be assessed on using good English organising information clearly and using specialist ter
53. more results to calculate a mean If the candidate answers No they may refer to eg all points on the graph lying close to the best fit line Reference to lack of time may be allowed for 1 mark at the teacher s discretion but should be annotated Credit should be given to candidates who either plan to do repeats before doing the practical work or who realise the need for repeats after collecting the results for certification from June 2014 onwards 39 Section 2 0 marks Q No 1 c No creditworthy response 1 mark At least one end of the range is correctly stated Another value of the independent variable is suggested although it may not be appropriate 2 marks The range is correctly stated according to the candidate s own results Another appropriate value of the independent variable is suggested The reason for the additional value is unclear or inappropriate 3 marks The range is correctly stated according to the candidate s own results Another appropriate value of the independent variable is suggested The reason for the additional value is clear and appropriate Additional guidance unclear The values given should be checked against the results table An appropriate extra reading will usually be one of the following e an intermediate reading to fill in a gap perhaps where the trend line becomes The range may be given f
54. ms where appropriate From the research that you have done describe in detail how you are going to do your investigation You should include e the equipment that you plan to use e how you will use the equipment e the measurements that you are going to make e how you will make it a fair test e arisk assessment 9 marks Equipment Escherichia coli in culture solution disinfectant solution 12 petri dishes with agar in loop pippetes test tubes sticky tape incubator Plan 1 Use a pippete to measure out 5cm3 of disinfectant into one test tube 4cm3 into another test tube then 3 2 and 1 Add water to the tubes so you have 5cm3 in each tube Put 5cm3 of water into another tube Label all the tubes so you know what s in them 2 Get another pippete and put 1cm3 of bacteria solution into all the tubes Let them stand for five minutes 3 Put the amount of bacteria solution you found in the preliminary experiment into six of the petri dishes 4 Spread it out in each dish using a loop You have to put the loop in the flame each time before you use it 5 Put the lid on the dishes and tape them up put the tape across the dish not around the lid 6 Repeat steps 3 4 and 5 for the other petri dishes Continue your answer on the next page Turn over gt for certification from June 2014 onwards 19 Step 2 Reporting on the planning and research Do not write outside the 4 box 7 Put all
55. ndidates notes and the class or teacher obtained secondary data and to write their evaluation of their investigation If candidates did the practical work in groups they must clearly identify the data that has been collected under their own direction This part of the controlled assessment should be completed in two to three normal lessons about 4 hours Helpful hints if the candidate s own plan is unworkable unsafe or unmanageable in the laboratory the teacher may provide them with a method to use for collection of data it is at this stage candidates should be given pooled classroom data and or teacher derived data from the same investigation to use in their analysis and evaluation candidates may use ICT in their analyses where appropriate candidates work must be taken in at the end of one session and kept securely until the next session Candidates must not be allowed to work on their report between sessions before they start their analysis and evaluation make sure your candidates know how to e analyse results and draw conclusions e match results to a hypothesis e evaluate their method of collecting data e analyse secondary data both collected and provided e use secondary data to validate their own work Step 5 Marking the controlled assessment e The candidates reports are marked internally using the mark guidance supplied by AQA e Marking should be done in red ink and annotations made where
56. nical after the experiment flask at the same time as adding the alkali from the burette 68 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 7 The effectiveness of antacid remedies Improvements to be made Reasons Use pure calcium carbonate There was some marble left at the end instead of powdered marble which could have been impurities which might have affected the reliability of my results Change the experiment Sodium hydroxide can form crystals in it so that the acid was in the if left around too long This could block burette and not the sodium up the tap on the burette affecting the hydroxide results Use a pH meter instead of It was difficult to get the exact colour the universal indicator change as it sometimes looked yellow green and sometimes looked blue green With a pH meter would only have to look for a number 7 for neutral on the screen Use a magnetic stirrer It was hard to swirl the conical flask and instead of mixing the conical open the tap on the burette at the same flask by hand time By using a magnetic stirrer it would be much easier Use a glass pipette and think might have not measured the filler to measure out the acid correctly in the measuring cylinder hydr
57. nt variable to be investigated the range interval and number of repeat readings they should take Research Candidates need to carry out research into an application of the investigation they are carrying out This research could take different forms such as internet searches book and journal searches or questionnaires and surveys Candidates should decide for themselves an appropriate method of research for their investigation The research could be done as a homework session and written notes made Key points e Collectively candidates could produce a huge variety of methods to perform their practical work If the teacher decides that the method produced by the candidate s is unworkable unsafe or unmanageable then the teacher may provide a method for candidates to use in the practical session AQA will supply suggestions for contextualisation of the task and suggestions for approaches to the task Teachers are free to choose to use or adapt these suggestions to suit their candidates or to use their own ideas for certification from June 2014 onwards 51 Step 2 Reporting on the planning and research Candidates must work on their own under direct supervision to write their introduction plan and risk assessment for their investigation They may use the notes they have made during their research in writing their plan This stage should take one or two normal lessons to complete Teachers must colle
58. ochloric acid think a pipette would give a more accurate result Make sure there are three This way my results will be very reliable repeats all within 0 5ml of each other Check my results with three This way my results will be more valid other people in the class 6 6 for certification from June 2014 onwards 69 Marking the sample controlled assessment Science B Step 1 Research 0 marks Level 1 Level 2 Level 3 Sources are mentioned www bbc com heartburn about com www ehow com and www practicalchemistry org An application is given 1 mark The application is described The research has been used as a basis for the investigation 1 mark A scientific explanation has been given discussing acid and alkali neutralisation 1 mark Three research sources have been given and the research has been used as a basis for the investigation into the effect of antacids 1 mark 70 for certification from June 2014 onwards Total 4 4 marks Step 2 Planning 0 marks Level 1 GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Level 2 Level 3 The purpose of the investigation is given as an investigation into how effective an antacid is 1 mark The variables are given in the fair testing table on page 2 and in the variables table on page 3 1 mark The plan is organised and could b
59. oric acid for antacids A E My means are in the table below didn t include the third result for sample D in the mean as it looks like an anomalous result Antacid Volume of sodium hydroxide Mean volume of sodium hydroxide ml needed to neutralise ml needed to neutralise dilute dilute Se acid hydrochloric acid o05 16 70 er for certification from June 2014 onwards 65 Step 6 The effectiveness of antacid remedies used the means to draw this graph Mean volume of NaOH used to titrate and neutralise the acid cM Antacid 66 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 6 The effectiveness of antacid remedies Looking at the secondary data provided think that the antacid E must have between 0 05 and 0 07g of calcium carbonate in it as the titration value was 24 6ml My results were between 30 5 and 20 8ml for the same amounts Antacids A B C and D must have between 0 07 and 0 1g of calcium carbonate in them as the titration values were 20 12 65 22 5 and 16 62ml My results were between 20 8 and 10 3ml for these amounts To make my results even more reliable should have repeated the anomalous result for the 1st attempt at 0 07g and not just left it out of my mean could have kept on repe
60. otheses e devise appropriate methods for the collection of numerical and other data e assess and manage risks when carrying out practical work e collect process analyse and interpret primary and secondary data including the use of appropriate technology e draw evidence based conclusions e evaluate methods of data collection and the quality of the resulting data Candidates should be given the hypothesis The survival and growth of microorganisms depends upon the concentration of disinfectant The teacher should describe the context in which the investigation is set and outline the hypothesis that is to be investigated Once the candidates have researched and written up their own plan in Section 1 of the ISA they should carry out their investigation providing that this is workable valid safe and manageable in the laboratory Candidates need to test the hypothesis They should research two possible methods to investigate it and develop a detailed plan for one of these methods Candidates will need to decide which variables need to be controlled in order to investigate the hypothesis and research a method that could be used with particular reference to hazards and risk assessment Candidates will be required in Section 1 of the ISA to provide a full plan of the method that they have chosen to use Important In this ISA candidates will need to be given the results of one other group in the class or a s
61. ould Could be spilt in room Use pipette to hazcards cause skin on your skin measure out solution allergy very easily so it doesn t come into Slips or skin contact Wash falls if hands carefully if you spilt get it on you Clear up all spillages with paper towels 58 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 3 The effectiveness of antacid remedies Equipment Hazard Control measure Source of procedure information chemical used hydrochloric Irritant Medium as it Clear up any spillages Cleapss acid 0 1M can can be spilt immediately using hazcards damage very easily and paper towels Wash Use British the skin looks like hands well after the Red Cross and eyes water so you practical just in case website for Slips or might forget Wear goggles at all information falls if to wash it times Know the first on 1st aid spilt off aid for chemicals in the for eyes or on the skin chemical Make sure there s no burns metals left lying around as acid reacts with them Irritant Medium as it Clear up any spillages Cleapss can can be spilt immediately using hazcards damage very easily and paper towels Wash Use British
62. ould be able to accommodate everything that the candidate is going to measure and record during the investigation The table should include appropriate headings and units After the candidate has produced a table the teacher will mark the blank table When the table has been marked the teacher may return it to the candidate to use in the investigation Alternatively teachers may supply a blank table in which candidates can record their results Section 1 of the ISA high control Candidates take section 1 of the ISA written test Up to 45 minutes is allowed for this The test may be taken in the normal teaching room provided that candidates can be accommodated in such a way as to prevent any copying or unauthorised collaboration Any access arrangements that apply to individual candidates for written papers eg extra time for statemented candidates or the use of a scribe or a reader will also apply to the ISA Section 1 of the ISA will contain questions about the methods that candidates have researched and is worth 20 marks of the overall 50 allocated to the controlled assessment Each candidate may use their candidate research notes sheet made during their research Risk assessment 16 Section 1 will also contain questions about the hazards and risks associated with the researched methods Key points Candidates will need to carry out a risk assessment in order to be able to answer some of the questions in section 1 M
63. pose For their research candidates may use technology such as the internet or CD ROMs textbooks or any other appropriate sources of information They should also research how the results of the investigation might be useful in the specified context There is no set time allocation for this research but it is anticipated that it should take no longer than three hours of work This research may be done in the laboratory or elsewhere The teacher should check and sign the Candidate Research Notes before allowing the candidate to use them during the completion of Section 1 of the ISA These must be checked to ensure that they do not include plagiarised text or a pre prepared draft The candidate may use their Candidate Research Notes while completing Section 1 and Section 2 of the ISA When the candidate has completed Section 2 the notes should be stapled to the ISA Stage 2 Reporting on the planning research High control For this stage candidates must work individually under direct supervision After the Stage 1 planning session candidates should be given Section 1 of the ISA and should work on their own under controlled conditions to answer it Candidates should take their Candidate Research Notes into the formal assessment period Section 1 will require candidates to e consider the variables independent dependent and control that they will need to manage during the investigation e report on their research into how to test the h
64. pplied by AQA e Marking should be done in red ink and annotations made where necessary to show the moderator the reasons for the decisions Helpful hints e candidates may improve their marks by carrying out another controlled assessment appropriate to that subject but not the same one that has already been completed e if more than one controlled assessment has been completed submit the one with the highest mark 8 for certification from June 2014 onwards Key points To view the teachers notes make sure you have access to e AQA If not register at https extranet aga org uk You will be provided with your own controlled assessment adviser Contact details for your adviser can be found in teacher online standardisation on e AQA For units 2 and 3 the candidates must supply their own hypothesis If you have any questions about the ISA call the GCSE Science subject team on 01483 477 756 or email science gcse aqa org uk GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Administration teachers notes Controlled Assessment Science A ISA BU1 x Microorganisms Specimen For moderation in May 20xx Teachers Notes This ISA relates to Science A Section B1 1 2 Keeping Healthy Topic of investigation Section B1 1 2c The body has different ways of protecting itself against pathogens Overview Candidates should e plan practical ways to answer scientific questions and test hyp
65. r or as to whether or as to whether or not the results are not the results are not the results are reproducible reproducible reproducible A simple A detailed explanation is given explanation is given supported by an supported by at example from the least two examples results this may from the results be a qualitative example referring to a pattern on the results Additional Note that the answer should refer to the class or teacher s results and not simply to guidance the expected result A statement as to whether or not the results are reproducible might be other people have got the same results A simple explanation of this might be they have got the same graph A more detailed explanation might be when we used 50 concentration we got no growth of bacteria but others did for certification from June 2014 onwards 41 Section 2 0 marks 1 mark 2 marks Q No 2 a No creditworthy Both axes labelled with Both axes labelled with response the variables ignore any the variables ignore any units given units given and an appropriate line has been drawn Additional Accept axes drawn either way round i e it does not matter which axis the guidance concentration is on The line should be a curve approximately matching the pattern shown by the data in case study 1 No values need to be shown on either axis and the line may intercept either axis Section 2 0 ma
66. rch notes The teacher must sign and date the front covers of section 1 and section 2 of the ISA The papers must be kept in a secure place and must not be returned to the candidates These marking guidelines are necessarily generic Additional guidance on how to relate these generic marking guidelines to particular investigations is given below the generic section Read through the whole of the candidate s answer and use the marking guidelines below to arrive at a best fit mark Section 1 0 marks 1 mark 2 marks 3 marks Q No 1 No Two relevant Two relevant Two relevant creditworthy sources are clearly sources are clearly sources are clearly response identified identified identified or and and one relevant sources the usefulness of the usefulness of is identified and the one of the sources both sources is usefulness of the is commented on explained anda source commented comparison made on Additional An identified source is referred to by title and author or for websites at least the name guidance of the web page should be quoted Any identified source should be capable of being accessed by the moderator A clear comment on only one of the sources may be sufficient to gain 3 marks if the answer implies a comment on the other source If candidates have taken part in peer discussion as part of their research simply stating this is not sufficient to qualify for quoting a source Similarly reference to
67. rette 5 Add the alkali to the acid using the tap to control the flow Stop when the universal indicator turns green and record the volume of sodium hydroxide added to the acid This is the rough titration which will give me an idea of when the colour change occurs so can do the rest of the results very carefully 6 Repeat 3 times but adding the alkali slowly to get an accurate reading of the volume added 7 Now measure out 0 02g of calcium carbonate and add to 50ml of hydrochloric acid in the conical flask Mix well and wait for all fizzing to stop 8 Titrate the remaining acid to see what volume of sodium hydroxide is needed to neutralise it Record the result and repeat 3 times to check reliability 9 Repeat this for 0 05 0 07 and 0 10g of calcium carbonate and repeat each one three times 10 Calculate mean volumes of sodium hydroxide needed to neutralise th remaining stomach acid by adding the three results together and dividing it by three 56 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 2 The effectiveness of antacid remedies Variables Independent Dependent Mass of calcium carbonate Amount of sodium hydroxide added to the acid g 0 1M added to neutralise the acid ml think that when more calcium carbonate is
68. ria varies with the concentration Comments 2 a of disinfectant e The axes are correctly 2 marks labelled units are not essential here and the curve is an appropriate reflection of the data 2 marks Number of colonies of bacteria that grew Concentration of disinfectant cm per dm of water Hypothesis The survival and growth of microorganisms depends upon the concentration of disinfectant 2 b Look at Case Studies 1 2 and 3 Explain whether or not the results in Case Studies 1 2 and 3support the hypothesis you Comments 2 b were given e A clear indication that case To gain full marks your explanation should include appropriate examples from the results studies 1 amp 2 support the a a 3 hypothesis and there is 3 marks a reference to the general trend in both However there is no reference to the The results for case study 1 and case study 2 both support the hypothesis anemiei hese os Ue Because less bacteria grow when the disinfectant is stronger But case study 3 is about using different disinfectants and doesn t look at e There is recognition how strong they were You should have used different strengths of the that case study 3 is disinfectants in case study 3 to test the hypothesis inappropriate along with an explanation as to why it is not appropriate 2 marks 32 for certification from June 2014 onwards Step 5 Analysing results GCSE SCIENCES GUIDANCE ON CONTROLLED ASS
69. rks 1 mark 2 marks No An alternative An alternative creditworthy method is outlined method is outlined response briefly although briefly some of the Full detailed plans are not required for the alternative method necessary steps may not be clear A simple suggestion is given as to why this alternative method would not have been as good as the one chosen 3 marks An alternative method is outlined briefly An explanation is given as to why this alternative method would not have been as good as the one chosen Suggestions regarding lack of specific named equipment are sufficient as a sensible explanation Table for the results 0 marks 1 mark 2 marks Q No 5 No table or a table with A table with incomplete Correct headings and incomplete headings or headings or units for the units present for all units for the measured measured variables measured variables variables Fewer than half of the At least half of the required elements are required elements should present be present Additional The table should be able to accommodate all the variables that the candidate guidance is going to measure or record during the investigation There is no need for the candidate to include columns for repeats means or derived values 38 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Section 2 0 marks 1 mark 2
70. rks 1 mark 2 marks 3 marks Q No 2 b No A simple correct Simple correct Simple correct creditworthy statement is made statements are statements are response about at least two made about case made about case of the case studies studies 1 2 and studies 1 2 and 1 2 and 3 as to 3 supported by 3 supported by whether or not a more detailed a more detailed they support the explanation of one explanation of hypothesis of them both case studies 2 and 3 Additional An example of a clear statement for case study 1 is the greater the concentration guidance the fewer colonies bacteria grow Further explanation for case study 2 could include reference to the variation in results between the two tests Further explanation for case study 3 will be that results are based on type of disinfectant rather than concentration 42 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Section 2 0 marks 1 mark 2 marks 3 marks Q No 2 c No A comment is made A comment is made A comment is made creditworthy as to whether the as to whether the as to whether the response advice is supported advice is supported advice is supported or not or not or not There is a simple There is a There is a statement that uses statement that uses statement that uses information from the information from the information from the graph to support the graph to support the
71. rnative method is outlined briefly There is no specific detail although full procedures are not required It would be difficult for anyone to follow this Two suggestions are given as to why the method would not be as good as the chosen one 2 marks Comments Q5 The average column is 2 marks unnecessary as this is a derived value Strength of Amount of Amount of Number of Number of Average Concentration is referred to disinfectant water used disinfectant bacteria bacteria as strength the unit cm used cm that grew that grew is given in dish 1 in dish 2 e Reference to number of 0 5 0 bacteria is sufficient to 20 4 1 imply numbers of colonies 40 3 2 in this case bacteria that 60 2 3 grew is the parameter and 80 1 4 number is the unit 100 0 5 2 marks END OF QUESTIONS Total for Section 1 16 Copyright 2010 AQA and its licensors All rights reserved for certification from June 2014 onwards 21 Step 3 Practical work The practical work limited control 22 Candidates may use the method that they have chosen and planned If the teacher decides that the method produced by the candidate s is unworkable unsafe or unmanageable then the teacher may provide a method AQA will supply a method that may be used in such circumstances The marking guidelines supplied by AQA will provide teachers
72. rom highest to lowest or from lowest to highest or as a single figure indicating the differences between the highest and lowest values Units should appear at least once e a reading outside the range already investigated perhaps to see if the trend continues 40 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Section 2 0 marks 1 mark 2 marks 3 marks Q No 1 d No A valid statement A valid statement A valid statement creditworthy is made about is made about is made about response whether or not the whether or not the whether or not the results support the results support the results support the hypothesis hypothesis hypothesis The answer includes The answer includes either a reference to areferencetoa a pattern or some pattern and some examples from the examples from the results results Additional The candidate s statement s must match the candidate s own results guidance An example of a pattern might be the stronger the concentration of disinfectant the more bacteria were killed An example of results quoted in support might be At 20 concentration the bacteria count was 50 but at 100 concentration all bacteria were killed Section 2 0 marks 1 mark 2 marks 3 marks Q No 1 e No A simple correct A simple correct A simple correct creditworthy statement is made statement is made statement is made response as to whethe
73. s of unworkable unsafe or unmanageable or is this left to a teacher s discretion Answer This is left to the discretion of the teacher In terms of how this will affect the marks awarded to a candidate s method as a general rule if a plan is unmanageable in that it requires equipment that is not available then no marks will be lost as per the marking guidance If however a plan is unsafe because it would mean a breach of health and safety procedures then this may be subject to a loss of marks again as per the marking guidance Question What is quality of written communication Answer Quality of written communication QWC is a form of requirements where a candidate needs to structure their answer in a logical fashion using correct spelling punctuation and grammar as well as supplying specialist terms where appropriate Please refer to the guidance on quality of written communication document supplied by AQA for further details Question What amount of teaching time is likely to be required to conduct the new controlled assessments Answer Approximately 5 to 6 hours dependent on circumstances Question What is the difference between an ISA and the Science B controlled assessment Answer In Science B there are no structured written papers Although timings are suggested in Science B for various stages of the controlled assessment exact timings are not prescribed as in the ISA for certification from June 2014
74. sis that you investigated You should use any pattern that you can see in your results to support your answer You should include examples from your results 3 marks Yes my results do support the hypothesis because when there used stronger disinfectant got less bacteria and when used weaker disinfectant got more bacteria The most bacteria grew when there was no disinfectant You have been given a set of results obtained by other people Do these other results show that this investigation is reproducible Explain your answer using examples from your results and the results of other people 3 marks Yes All the class got the same sort of results Turn over gt Do not write outside the box Comments Q1 d e The candidate does not quote values from the results only correctly describing the overall trend within the results There is no reference to the reducing effect of increasing disinfectant concentration at higher concentrations 2 marks Comments Q1 e The response indicates the other results support the hypothesis There is no reference to trends patterns or specific values 1 mark for certification from June 2014 onwards 31 Step 5 Analysing results 2 You have been given a Secondary Data Sheet that provides results from similar investigations 2 a Draw a sketch graph of the results in Case Study 1 The graph should show how the number of colonies of bacte
75. t of their final report In the practical stage candidates may work singly or in groups to obtain their data However each candidate must record and process the data individually and must identify the data collected under their own direction In addition to the secondary data given in the Notes for Candidates candidates should be given group or teacher data to analyse and compare with their own in order to comment on the validity of their own work Area of Investigation This work should be carried out during the teaching of the section relating to Unit 2 section 3 4 1 2 Chemistry in action in the body e Our stomach contains hydrochloric acid Sometimes excess acid can make us feel very uncomfortable and may cause heartburn and nausea e Pharmacologists use their knowledge of neutralisation reactions to monitor and control stomach acid using antacids They test the effectiveness of antacids in terms of how effectively they neutralise excess stomach acids before they are sold to the consumer e Name some hazards of acids and bases and some control measures that can be put in place to minimise risks from them e Understand that the stomach works most effectively in acid conditions by helping to break down food e Explain how an antacid neutralises excess stomach acid to help to treat heartburn and nausea Contextualisation of task The task should be put into a context so that candidates understand the reason for the investigation t
76. tant Research sources 1 AQA Science by Jim Breithaupt Ann Fullick Patrick Fullick published by Nelson Thornes 2 Internet http Avww selah k12 wa us SOAR SciProj2003 CharleyW html Method s 1 Mix different amounts of disinfectant and water 5cm3 Add bacteria 1cm3 Leave for 5 minutes Spread onto agar heat loop Incubator Count colonies 2 Mix different amounts of disinfectant and water Dip in filter paper pieces Put filter paper onto agar that has bacteria on it incubator Measure width of circle where bacteria are killed Equipment Disinfectant water bacteria clock pippetes loop incubator tape Risk assessment issues sterilise loop tape up the dish don t open dish Context Cleaning kitchen surfaces Relating the investigation to the context Cleaning kitchen surfaces is important or you can pass bacteria from food like meat to bread when your making sandwiches Chicken has salmonella and you can get bad food poisoning So you have to use disinfectant strong enough to kill the bacteria or you might die Bottle of disinfectant under the sink in our kitchen says it kills 99 of all known germs for certification from June 2014 onwards 15 Step 2 Reporting on the planning and research Blank table for the results high control Just as in the previous specification candidates will be required to independently produce a blank table for their results The table sh
77. ted risks 1 mark have been identified Control measures have been suggested 1 mark All the hazards 1 mark and risks 1 mark have been identified Most control measures are based on scientific reasoning and even though some control measures are based on common sense this is only where appropriate The risk assessment is thorough 1 mark Step 4 Collecting data 0 marks Level 1 Level 2 Total 8 8 marks Level 3 Titrations have been has been recorded 1 mark carried out and the results recorded in a table so observations have been made 1 mark and data The observations are accurate 1 mark The data has been recorded with no errors 1 mark and the candidate has recognised that one of the results for mass 0 07g should be repeated 1 mark The candidate has only recorded the final result and so is not awarded the observation mark here The candidate needs to record all the measurements or observations made in order to gain this mark This could be done with a table showing initial and final volumes for the titres Even though the rough titrations have not been recorded to 1 decimal place the rest of the data is recorded with consistent significant figures and with correct headings and units This is acceptable for 1 mark The anomalous result for 0 07g has been identified and the candidate would have repeated this if possible 1 mark 72 for certif
78. the dishes in the incubator for 2 days 8 Count how many colonies are growing in each dish Each colony comes from one bacteria so l Il Know how many bacteria were alive 9 Dont open the dishes Fair test all the tubes have the same amount of bacteria put in them and the same amount of disinfectant solution All the petri dishes have the same sort of agar They are all put in the incubator together for the same time Risk assessment Bacteria might be harmful they can even kill you Never open a dish with bacteria in it Wash your hands afterwards Comments Q3 20 The equipment list omits a Bunsen burner referred to in step 4 On step 3 of the method it is not clear which bacteria solution the candidate is referring to It appears that it s the neat culture but the candidate probably intends this to be the bacteria disinfectant mixture that has just been made up in steps 1 amp 2 Taping the lid of the dish is an appropriate safety measure In step 7 there is no indication of temperature either here or in the equipment list Some control variables identified eg volumes time but others omitted eg temperature Step 8 identifies measurements to be made The method allows the collection of valid results The answer is coherent and uses a range of specialist terms Spelling is generally good as is punctuation occasional errors eg pippete and the omission of one or two capital letters
79. their own notes or exercise book alone is insufficient for certification from June 2014 onwards 35 Section 1 0 marks 1 mark 2 marks 3 marks Q No 2 No A suitable control A suitable control A suitable control creditworthy variable is stated variable is stated variable is stated response Only one value to be investigated in the preliminary experiment is The limits of the range to be investigated in the preliminary suggested experiment are The dependent appropiate variable is stated A statement but details concerning how the concerning its measurement are incomplete dependent variable values obtained could be used to determine the best value for the control variable has been made Additional guidance A suitable method may involve measuring the extent of growth of colonies of bacteria after different time intervals and then comparing the results The preliminary investigation may involve testing two ends of a range to see if there is sufficient variation or to establish a suitable value A suitable control variable might be the length of time for which the colonies of bacteria are allowed to grow A statement concerning how the results could be used might be eg if the bacteria colonies haven t grown much I would have to extend the time before measuring them An example of a detail for the dependant variable might be measuring the diameter of the ring of growth of
80. ty for centres but centres should be aware of the fact that a controlled assessment cannot be submitted for moderation before its operational period 2 Choose a controlled assessment task from e AQA Controlled assessment tasks are available on e AQA https extranet aga org uk Please check the front of the ISA materials to ensure that they are valid for the subject and series for which you intend to use them 3 Understand the new criteria and what candidates need to complete Your science candidates will need to e plan practical ways to answer scientific questions and test hypotheses e devise appropriate methods for the collection of numerical and other data e assess and manage risks when carrying out practical work e collect process analyse and interpret primary and secondary data including the use of appropriate technology e draw evidence based conclusions e evaluate methods of data collection and the quality of the resulting data Your Additional Science Separate Science and Further Additional Science candidates will also need to e develop hypotheses Each year AQA will supply one ISA each for Units B1 C1 and P1 These may only be used for Science A one ISA each for Units B2 C2 and P2 These may only be used for either Additional Science or the Separate Sciences two ISAs each for Units B3 C3 and P3 These may be used for the Separate Sciences only one of each of the ISAs for Units B3 C3
81. ubject when making entries but amendments can be made later A mark is not needed at the time of entry but must be submitted to AQA and the moderator by 7 May Marks must be submitted on the Centre Mark Form CMF The centre should also circle the highest and lowest non zero mark for each subject on the CMFs The table overleaf shows the codes needed for controlled assessment entry and the ISAs that may be used with the candidates for certification from June 2014 onwards 75 Subject and certification code Entry code for controlled assessment unit Science A route 1 4405 SCA4P Science A route 2 4406 Additional Science route 1 4408 AS4P Additional Science route 2 4409 Biology 4401 BL4P Chemistry 4402 CH4P Physics 4403 PH4P Further Additional Science 4410 FAS4P Science B 4502 SCB4P 10 Centres should be careful to ensure they submit ISAs 11 12 13 14 15 16 76 appropriate for the subject that candidates are entering and for the appropriate moderation date as marks from inappropriate subjects and out of date ISAs will not be accepted A separate entry is needed for each of the required units and for the overall subject before certification Entry for centre assessed unit is not automatic For example for GCSE Biology foundation level you need to enter BL1F BL2F BL3F and BL4P Centres should also enter the certification code of 4401 Please refer to the specificat
82. une 2014 onwards Key points Where methods generated are unmanageable or unsafe the AQA mark guidance will dictate how marks are apportioned and will take into account experiments that are scientifically accurate but not possible due to circumstances such as lack of equipment GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 4 Data processing analysis and evaluation Candidates must work on their own under direct supervision to process and analyse their own data Candidates should be given pooled classroom data and or data obtained by the teacher to help them in their analysis and to compare with in order to validate their own data Candidates should use and refer to the secondary data provided in the notes for candidates in their analysis They should consider any questions included in the notes for candidates in their write up Step 5 Marking the controlled assessment The candidates plans risk assessments data analyses and evaluations are all marked internally using the marking guidance supplied by AQA This guidance is available in the specification and at the back of each set of teachers notes Marking should be done in red ink Annotation should be used to show the reasons for mark decisions The next few pages show a sample controlled assessment Following this is a commentary explaining the marking of each strand in the assessment grid The assessment grid can be found in the Science B
83. we might get food poisoned You have to make sure you clean the kitchen after having fresh meat or chicken because you can get salmonella 2 Make sure that you hand in your Candidate Research Notes results tables and chart or graph with this paper You will be awarded up to four marks for your chart or graph 4 marks END OF QUESTIONS Permission to reproduce all copyright material has been applied for In some cases efforts to contact the copyright holders have been unsuccessful and AQA will be happy to rectify any omissions of acknowledgements in future papers if notified An idea from the investigation has been linked to context and findings from the investigation have been related to the context However there is little detail in the explanation Further information from research has been quoted marks Comments Q4 Total for both sections 38 50 2 Both X and Y axes are fully labelled with units The points are plotted correctly to within a tolerance of 1mm An appropriate curve is drawn A suitable straight line would also have been acceptable from these plots marks for certification from June 2014 onwards 33 Step 6 Marking the ISA Marking e Sections 1 and 2 of the ISA are marked internally using the mark guidance supplied by AQA e Marking should be done in red ink Where necessary annotations should be used to show the reasons for mark decisions e Full marking
84. with indicators as to how marks will be awarded based on the methods candidates choose There is no specified time limit for the practical work although it is anticipated that most experiments should be capable of being completed within a one hour lesson If necessary however the experiment may be continued over a number of lessons Any paperwork eg result tables should must be collected in at the end of the first lesson and returned to the candidate at the start of the next lesson In some ISAs it will be necessary for the teacher to pool the results of the class This is so that each candidate may be allowed to see the results of others in order to better evaluate them and form a conclusion In cases where there is only a single candidate then the teacher s own results may be used for comparison for certification from June 2014 onwards Key points e As before it is possible that candidates based on their research will be carrying out a variety of different methods Where this occurs or where candidates methods are deemed to be unworkable unsafe or unmanageable teachers can provide their own material or the method given by AQA Where the methods generated are unworkable unsafe or unmanageable then the AQA marking guidelines will dictate how marks are apportioned and will take into account experiments which are scientifically accurate but not possible due to circumstances such as lack of equipment
85. ws that if added 0 126g of calcium carbonate to the acid it would be completely neutralised plotted these figures onto the graph and it clearly shows that the amount of acid is greatly reduced by the calcium carbonate being added My teacher suggested that should do a line graph but told me to do my own scales didn t use the 1st attempt for 0 07g in my mean as this was an anomalous result compared to the other two The other two results were quite close so think my work will still be reliable for certification from June 2014 onwards 63 Step 5 The effectiveness of antacid remedies Concentration of HCI mole Mass of calcium carbonate added g 64 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 6 The effectiveness of antacid remedies 6 ANALYSING DATA found out that calcium carbonate is a good chemical to use as an antacid as the number of moles of hydrochloric acid remaining after the reaction was greatly reduced For example when 0 02g was added the HCI was 0 0043M but when 0 10g was added it was only 0 00103M If you double the amount of calcium carbonate you halve the amount of acid left used the secondary data provided to work out the mean volume of sodium hydroxide needed to neutralise dilute hydrochl
86. y work and that they are safe to use A chemist might do an investigation like mine when testing new antacid remedies They would use alkalis to neutralise the acids Research and development sections of pharmaceutical companies have the role of producing and testing new remedies researched the ingredients of some remedies on http heartburn about com and found that Tums contain famotidine 10mg calcium carbonate 800mg and magnesium hydroxide 165mg Maalox contains just calcium carbonate know we have this in school so want to use calcium carbonate in my experiment On www ehow com it said that stomach acid is 0 16M hydrochloric acid so think I ll use the same in my experiment so it s similar to real stomach acid found a method for investigating ant acids on www practicalchemistry org which said that burettes allow you to measure the acid accurately so want to try to use one in my experiment could use some maths to work out how strong the alkali and remaining acid are 54 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Step 2 The effectiveness of antacid remedies 2 PLANNING Aim The purpose of my experiment is to investigate how effective calcium carbonate is as an antacid treatment by using different amounts to neutralise a known amount of h
87. ydrochloric acid and then titrating this against sodium hydroxide EQUIPMENT Equipment Why used Goggles To protect our eyes 50ml measuring cylinders To measure out the acid and alkali 0 1M hydrochloric acid To react with the alkali Calcium carbonate powder To neutralise the acid Antacid 0 1M sodium hydroxide To titrate with the acid Electronic balance To weigh the calcium carbonate Clamp and stand To hold the burette White tile To see the change in colour easily Burette To titrate the alkali with acid Filter funnel To fill the burette Conical flask To mix the acid and alkali Universal indicator To show when it s neutral Spatula To measure out the calcium carbonate FAIR TESTING What l Il keep the same What I ll change The volume and concentration of The mass of calcium carbonate hydrochloric acid and sodium added to the hydrochloric acid hydroxide used each time The same equipment throughout for certification from June 2014 onwards 55 Step 2 The effectiveness of antacid remedies Method Fill the burette with 50ml of 0 1M sodium hydroxide 2 Use a measuring cylinder to measure out 50ml of 0 1M hydrochloric acid and put it in a conical flask 3 Add a pipette of universal indicator and it should turn red Place a white tile and the conical flask under the bu
88. ypothesis they have been given e write a detailed plan of their chosen method e identify possible hazards and write down how the risks may be minimised e draw a blank table suitable for the method they have planned Candidates may choose to use technology to draw the table e g a computer spread sheet This must be done under the direct supervision of the teacher and may be done at any convenient time between the planning session in Stage 1 and the completion of Section 1 of the ISA While answering Section 1 of the ISA candidates must not be allowed to use notes textbooks the internet or any other source of help apart from their own Candidate Research Notes 10 for certification from June 2014 onwards GCSE SCIENCES GUIDANCE ON CONTROLLED ASSESSMENT Administration teachers notes Stage 3 Practical Work Limited control For this part of the investigation candidates may work individually or in groups Candidates may work in groups to carry out their plans but each candidate must contribute to the collection of data Candidates may use appropriate technology during the practical work e g data loggers or sensors If the teacher deems that the plan produced by the candidate is invalid unworkable unsafe unmanageable or for any other reason unsuitable then the teacher may provide a method An example of a suitable method is attached to these notes Candidates may use their own blank table for the results providing

AQA Science Controlled assessment in GCSE

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