Antibiotic casestudy

Background briefing: The arms race between humans and bacteria encourages disease-causing bacteria to evolve to evade our defences: mainly, our drugs.

The discovery of antibiotics in the 20th century helped humans to fight deadly diseases like syphilis and gangrene, but the more we use them, the greater the pressure becomes for   to evolve. Any genetic mutation that helps a bacterium beat a drug very quickly gets ‘selected’ and spreads throughout the bacterial   as the cells without the mutation die off. Doctors are then left with fewer treatment options, meaning that patients take longer to recover or are less likely to survive. Inappropriate use of antibiotics – including doctors prescribing the drugs unnecessarily and patients failing to completely eliminate infections by not finishing antibiotic courses – is making the problem worse by giving bacteria a chance to develop resistance.

To keep up with bacteria, drug companies need to develop entirely new classes of antibiotics. But the drug discovery and approval process is lengthy, and there are few incentives to develop antibiotics because they start becoming ineffective within a couple of years.

Imagine…

You’re a doctor in a country where TB infections have reached crisis levels. Although it was once treatable, now no patients respond to the first-line medications available.

  • How should these patients be treated?
  • How could you – and your patients – help to slow the development of resistant bacteria?
  • How can drug companies be encouraged to develop new treatments?
  • What role could better diagnostic tests play in reducing resistance?
  • Should antibiotic use be restricted?
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HIV link

Please can you post up your efforts so far for your coursework onto your blogs! Have a great half term and don’t forget to also keep revising and organising your notes! Ms W

My Cousin Dom talks about risk management in the worlds poorest countries. He has worked all his life in countries facing all sorts of challenges, whether it be disease, war, famine or environmental. He also wrote an article warning of the problem facing countries with Ebola and how we need to act fast! Very interesting chap my cousin 🙂

Here is Ben’s, Robert’s and Joe’s effort and here is Emmanuel’s and Mahdi’s. Well done chaps, I look forward to the next installment! Sorry B, R and J yours is upside down! 🙂

Home learning writeups and sheets that need completing and handing in:

2.4 Alveoli worksheet

2.6 Enzymes and protein structure

2.10 CF Protein

Core 1: Daphnia write up

Core 2: Beetroot write up

Core 3: Rates of Reaction: Trypsin and milk protein

Make sure these are all done before half term! Thanks, Ms W

And how curiosity didn’t kill the cat! http://m.huffpost.com/us/entry/5928716

It was really great to see everyone really immersed in Science and Chemistry, Biology and Physics learning last week. The Goldsmiths PGCE students really were amazing but the real stars of the show were our pupils – YOU!

Thank you so much for really engaging with the sessions and getting the most out of them – you did yourselves and us proud.

Now, the real work begins….A2 Biologists must now complete their preliminary experiments (Joe those maggots are already starting to pupate and I believe the woodlice arrived yesterday Ben!)

8 9 10 11  13 14 15 16 17 18 19 20 21 22 23 24 25 photo 1 photo 2 photo 3

AS Biologists your deadlines for Investigation write ups are:

Monday 6th October: Daphnia and the effect of caffeine on heart rate

Monday 13th October: Beetroot and the effect of temperature on cell membranes

Thanks again you were awesome! Best, Ms W

http://www.biology.arizona.edu/cell_bio/problem_sets/membranes/index.html

The requirements at A2 level require further progression by the student as evidenced by the submission of an individual investigation in Unit 6.

Students will carry out the recommended core practicals in Units 4 and 5 and their individual investigations.

Students will carry out practical work during the GCE Biology A2 course, which will be verified by the teacher using the criteria below and submitted to Edexcel using a verification of practical skills record.

The teacher will verify student’s ability to: a Use apparatus skilfully and safely via CORE Practicals

i         Apparatus and materials are handled correctly and safely and manipulative techniques are used in an appropriate and safe manner.

ii         The practical work is carried out in an organised, methodical and safe manner, with due consideration of the wellbeing of living organisms and the environment.

b Produce and record reliable and valid results

i         Measurements and observations are made with precision and recorded in a structured manner; variables are identified and the validity and reliability of results are justified.

ii         Possible systematic errors and random errors in generating results are identified and explained.

c         Present and analyse data

i         Use appropriate methods to analyse results, present data and identify trends, patterns and/or observations.

ii         Any apparent anomalies and inconsistencies are described, the methodology is evaluated and suggestions are made to improve or further the work of the investigation.

Unit 6 Individual investigation (45 marks)

Students will present a written report, of an experimental investigation they have devised and carried out. The Individual Investigation in Unit 6 is an individual practical project, which is designed to show progression from the internal assessment in the AS course.

Each student is required to carry out an extended practical project. It is suggested that it takes the equivalent of two weeks of normal lesson and homework time. Students will be assessed on their ability to plan and carry out experimental procedures, to interpret their experimental results and to report on their work.

At all times during the project, from initial planning to writing up, students should be encouraged to discuss their ideas with their teachers. This is particularly important in the early stages when students are choosing the topics of their investigations. Teachers may offer general guidance without penalty. The writing of the report must be entirely the student’s own work.

Assessment is based on written work produced by the student.

The report must include presentation and analysis of the student’s own numerical data. The report must be word processed and submitted electronically. This report will be marked by the teacher and the reports from selected students will be inspected by a moderator appointed by Edexcel, or alternatively the reports can be externally marked by Edexcel.

This assessment may be carried out at any time during the course, but the work should reflect the standard expected at Advanced GCE.

Organisation

Investigations must be linked to the content of the course, and have the potential to allow students to meet all the assessment criteria given.

Students must produce individual work. Two or more students may choose the same or similar topics, provided each works independently.

Normally laboratory or field work will be undertaken under the direct supervision of the teacher. If the nature of the investigation involves a student carrying out practical work outside the school or college environment, sufficient work must take place under direct supervision to allow the teacher to ensure that it is the student’s own work. The teacher must discuss the practical aspects with the student to establish that the student did undertake the work personally. This might

be done by asking about precise details of the work, the apparatus used, the practical problems encountered and how they were overcome.

Unit 6 Preparation

Students should do some background research for their individual investigation. This research should help them identify and define a biological question or problem that can be addressed and provide a clear rationale for their work. They should consult appropriate sources, which may include textbooks, magazines and journals, CD ROMs and the worldwide web. Reports should include a bibliography of the sources consulted and references to electronic materials should give the date of access and contain sufficient detail to allow the reader to check the source.

In advance of the data collection phase, students should devise and plan their experimental activities to make good use of the time and facilities available. They should consider appropriate methods, choose effective and safe procedures and select suitable techniques. They should decide what apparatus they will need, and check that this will be available for their use. They may devise their own apparatus or experimental set-ups, modify standard apparatus or use standard items in ways that are novel.

Students should have some idea of how they expect the work to proceed but should also be prepared to modify their plan in the light of initial results. It is, therefore, advisable that students should carry out a brief trial, in advance of the main data collection phase, to check the feasibility of their proposed work.

Unit 6 Experimentation

The report: Students are expected to use safe and skilful practical techniques that are appropriate to the purpose of the investigation and for the apparatus available. They should demonstrate an ability to set up apparatus correctly and use it effectively with due regard to safety.

Students should make sufficient and relevant observations and measurements, to an appropriate degree of precision, record these methodically, and modify procedures in order to generate results that are as accurate and reliable as allowed by the apparatus and investigative approach.

Students should interpret, explain and evaluate the results of their experimental activities using knowledge and understanding of biology. They should present their results appropriately in written, graphical or other forms. They should analyse their results statistically and draw conclusions, showing an awareness of the limitations of their experimental data and the procedures used.

Each student is required to produce a project report. Students should be encouraged to start work on their reports before they have completed their practical work. They should be allowed a further period of at least two to three weeks to produce their reports after they have completed their collection of data. The report must be word processed and submitted electronically.

Students should aim to produce well-organised and clear reports. They should select, organise and present information clearly and logically, present their work appropriately, select and use images to illustrate points clearly, and use standard conventions of spelling, punctuation and grammar. The report should be in the style of a scientific paper. Sub- headings should be used to aid organisation. The initial aim of the project should be stated clearly, as should any overall conclusions that have been drawn. The report should include a bibliography listing all reference sources consulted. Graphs, tables and diagrams should be used where they add to the clarity and conciseness of the report.

Credit will be given to reports that are clear and concise, show good use of English and appropriate biological terminology.

The investigation is marked out of a total of 45 marks, using the criteria given below.

Intermediate marks (eg 1, 3, 5) should be used when students have partially achieved a listed mark level of the criteria, but half-marks should not be used. Note that for each aspect, the criteria are hierarchical: for a mark to be awarded, all of the earlier mark levels must have been satisfied. A mark of 0 should be awarded if the work submitted is unworthy of any credit.

When a student fails to submit work by the due date specified by the centre, this should be indicated by recording A (for absence) in the mark record. Where more than one teacher has been involved in internal assessment of students, centres must make arrangements for internal moderation to be carried out, and details of this procedure must be available for the moderator if requested.

It is the responsibility of the teacher to ensure that the report submitted from each student is produced individually. In submitting the authentication certificate teachers accept the responsibility for ensuring that these conditions have been met.

Skills

Assessment criteria                  Level of response                                  Mark range

Research and rationale

a            There is some attempt to provide a rationale for the choice of investigation in terms of its scope and its relation to biological principles.

b            Few sources are consulted and their scope is limited in providing a context for the investigation, to assist with the planning or execution of laboratory or field work, or in informing the interpretation of results.

0–2 marks

a            There is a partial rationale for the choice of investigation. The biological background to the investigation is developed to some extent.

b            Information gathered from some relevant sources has some bearing on the context for the investigation, and assists, in a limited way, with the planning or execution of laboratory or field work, or to inform the interpretation of results.

3–6 marks

a            The rationale for the investigation is clear, in terms of its scope and relationship to biological principles.

b            Several relevant sources are consulted, and are used to provide a context for the project, to assist with the planning or execution of laboratory or field work, and to inform the interpretation of results.

7–9 marks

a            The rationale for the investigation is clearly justified in terms of its scope and appropriate biological principles are discussed.

b            Additional sources, beyond those that were most readily to hand or were initially suggested by the teacher, are selected. The material chosen is selected for its relevance to the investigation and it is used effectively to provide a context for the project, to assist with the planning or execution of laboratory or field work, and to inform the interpretation

of results.

10–11 marks

Planning

a            There is some attempt to plan and to select the method or apparatus chosen. Some relevant variables are identified.

b            Some potential safety hazards and the steps to avoid or minimise them are identified.

c            A trial experiment may be carried out.

0–2 marks

a            There is a plan for the investigation, with some explanation of the selection of apparatus and methods. There are some details of how variables are to be controlled, manipulated or taken into account and how relevant observations are to be made.

b            Most potential safety hazards, and the steps to avoid or minimise them, are identified.

c            A trial experiment is performed that has some bearing on the planning of the project.

3–6 marks

a            There is a clear plan of action, both for an initial trial phase and for the main period of data collection. Apparatus selected and methods chosen are appropriate to the investigation. There is discussion about how variables are controlled, manipulated or taken into account and about the collection of relevant observations or data.

b            All potential safety hazards are identified, and suitable steps taken to avoid or minimise them.

c            A well-thought out trial is conducted in advance of the main data collection phase, and is used to inform the planning of the investigation.

7–9 marks

a, b, c) There is evidence of thought and ingenuity in the design of experiments or the recording of data, with good attention to detail including the way in which variables are controlled, manipulated or taken into account and how relevant observations are made

or data collected. Apparatus is devised or modified to suit the project as necessary.

10–11 marks

Observing and recording

a            Some appropriate measurements and observations are recorded, which are adequate for the method used and reasonably accurate.

b            There is some repeating or checking of values obtained.

0–2 marks

a            Measurements and observations are recorded methodically and accurately in appropriate units, and some thought is given to precision and repeatability.

b            A reasonable number and range of observations and measurements are carried out. Any anomalous results are noted. There is some appropriate modification of procedures for data collection if necessary.

3–6 marks

a            Observations and measurements are carried out over a suitable range of values or conditions. Sufficient observations and measurements are made to allow a conclusion. Numerical results are recorded to an appropriate degree of precision.

b            Measurements and observations are repeated as appropriate. Any anomalous results are noted and investigated. If problems arise in the making of measurements or observations, procedures are adapted to ensure data is reliable.

7–8 marks

Interpreting and evaluation

a            There is some data processing. Statistical analysis is only completed with detailed guidance. Application of calculated statistical values is present, though limited or confused.

b            There is an attempt to apply biological principles.

c            Some conclusions are stated. There is some awareness of the limitations of experimental results and conclusions.

0–3 marks

a            Data is processed with some thought as to choice of method. The chosen statistical test(s) may be inappropriate or provide limited analysis of the stated hypothesis. Calculations are clearly set out but the interpretation of calculated values lacks detailed explanation. Some trends and patterns are identified.

b            Some attempt is made to interpret results using biological principles, and to draw conclusions based on experimental results.

c            Conclusions are supported by results. The limitations of results, and conclusions based upon them, are recognised. Any limitations of methods are recognised.

4–6 marks

a            Data are processed using appropriate methods that reveal trends and patterns. The chosen statistical tests are appropriate to the data to be analysed and the hypothesis to be tested. Calculations of statistical tests are clearly set out and interpreted, using a null hypothesis and 5 per cent confidence levels where appropriate. Trends and patterns are identified.

b            Results are interpreted using biological principles and concepts of Advanced GCE standard. Relevant biological principles are applied correctly throughout.

c            Conclusions are supported by results. The limitations of results, and conclusions based upon them, are recognised and evaluated. Any limitations of the procedure are commented upon, and sensible modifications suggested.

7–9 marks

Communicating

a            The layout of the report largely conforms to that expected of a scientific paper. The organisation of the report produced shows evidence of some thought and the aim of the investigation is stated. Images, when used, are relevant to the points made.

b            Data is presented in graphs, tables or diagrams, which are mostly appropriate and follow scientific conventions for presentation.

c            Spelling, punctuation and grammar are generally correct, some technical terms are used appropriately and most sources used are acknowledged in a bibliography.

d            Sources include at least one professional scientific journal.

0–2 marks

a            The layout of the report mostly conforms to that expected of a scientific paper with subheadings used effectively. The aim(s) and conclusion(s) of the investigation are stated. Images, when used, illustrate points clearly.

b            Data is presented in well-chosen graphs, tables or diagrams, which usually follow scientific conventions and mostly use SI units, where appropriate, correctly.

c            Spelling, punctuation and grammar are correct, appropriate technical terms are used throughout. Sources are selected and used appropriately and are correctly and clearly referenced within a properly constructed bibliography.

d            There is some discussion of the credibility of sources used.

3–4 marks

a            The layout of the report conforms to that expected of a scientific paper with appropriate and helpful subheadings. The organisation of the report shows evidence of thoughtful planning and the aim(s) and conclusion(s) of the project are clearly stated and discussed. Images illustrate the points effectively and enhance the clarity of the report.

b            Data is presented effectively in graphs, tables or diagrams that follow scientific conventions and are clearly and accurately labelled using SI units where appropriate.

c            Spelling, punctuation and grammar are correct, and appropriate technical terms are used throughout.

d            Sources used are evaluated with reference to their credibility within the wider scientific community.

5–6 marks

TOTAL NUMBER OF MARKS AVAILABLE

45