AS and A LEVEL. Delivery Guide H022/H422 BIOLOGY B (ADVANCING BIOLOGY) Theme: Controlling communicable diseases:

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1 AS and A LEVEL Delivery Guide H022/H422 BIOLOGY B (ADVANCING BIOLOGY) Theme: Controlling communicable diseases: October 2015

2 We will inform centres about any changes to the specification. We will also publish changes on our website. The latest version of our specification will always be the one on our website ( and this may differ from printed versions. Copyright 2015 OCR. All rights reserved. Copyright OCR retains the copyright on all its publications, including the specifications. However, registered centres for OCR are permitted to copy material from this specification booklet for their own internal use. Oxford Cambridge and RSA Examinations is a Company Limited by Guarantee. Registered in England. Registered company number Registered office: 1 Hills Road Cambridge CB1 2EU OCR is an exempt charity.

3 AS and A LEVEL BIOLOGY B (ADVANCING BIOLOGY) CONTENTS Introduction Page 4 Curriculum Content Page 5 Thinking Conceptually Page 8 Thinking Contextually Page 13 3

4 Introduction Delivery guides are designed to represent a body of knowledge about teaching a particular topic and contain: Content: A clear outline of the content covered by the delivery guide; Thinking Conceptually: Expert guidance on the key concepts involved, common difficulties students may have, approaches to teaching that can help students understand these concepts and how this topic links conceptually to other areas of the subject; Thinking Contextually: A range of suggested teaching activities using a variety of themes so that different activities can be selected which best suit particular classes, learning styles or teaching approaches. KEY only Click to view associated resources within this document. Click to view external resources A Level content only If you have any feedback on this Delivery Guide or suggestions for other resources you would like OCR to develop, please resourcesfeedback@ocr.org.uk. 4

5 Curriculum Content Controlling communicable diseases (a) the principles of vaccination (b) the role of vaccination programmes in the prevention of epidemics. (c) the biological problems in the development of vaccines and the use of vaccination programmes (d) the ethical issues related to the development and use of vaccines (e) the use of antibiotics in the treatment of communicable disease (f ) how the misuse of antibiotics can lead to the evolution of resistant strains of bacteria (g) practical investigations on the effect of antibiotics on Gram-positive and Gram-negative bacteria To include the different forms of vaccines (live vaccine, dead microorganisms, pathogen fragments) and the importance of booster vaccinations. To include reference to the establishment of herd immunity. To include issues with vaccine development, mutation rate and antigen variability (eg in HIV and the influenza virus(es)) and live vaccines. AND vaccine use storage of vaccine, distribution of vaccine and the nutritional status of the target population eg if protein deficient. To include the use of a vaccine in girls against Human Papilloma Virus (HPV) to prevent cervical cancer. HSW10 To include an outline of the modes of action of antibiotics eg inhibition of bacterial protein, DNA and cell wall synthesis. To include reference to TB and MRSA. To include the bacteriostatic and bacteriocidal effects of antibiotics and the effects of disinfectant use and other hygiene practices. M0.1, M0.2, M0.4, M1.1, M4.1 PAG1, PAG7 HSW3, HSW4, HSW5, HSW6, HSW8 5

6 Curriculum Content The control of communicable diseases by vaccination is arguably one of the greatest feats achieved by modern medicine but the topic provides a number of specific challenges for teachers. These include: being aware of developments with regards to antibiotic resistance and the control of antibiotic resistant bacteria in a clinical setting. stimulating students with enthusiasm for a strand of medicine that, due to its level of control and a stringent vaccination programme, rarely effects the developed world. evoking in students a balanced view of the ethical considerations surrounding vaccination and the economical costs of herd immunity. helping students to perceive sequences of events at the cellular and molecular level in what are likely to be very abstract concepts. Activity Resources Development of antibiotic resistance MRSA is used as the example to guide students through this four step guide to show the effect of antibiotics on the development of antibiotic resistant bacteria. Students could use the resource to gather information and present it in the form of a flow chart to cement learning and understanding. Types of Pathogen General descriptions of pathogens including bacteria, virus, fungi and protozoa are explained with examples of a disease that each pathogen causes. Students could be split into groups with each focusing on one pathogen. They could then present their findings to the class and summarise the findings on each type of pathogen. 6

7 Curriculum Content Activity Resources How vaccines work The NHS publish a timeline of when childhood vaccinations should be administered (select the NHS vaccination schedule tab). If it is utilised online, students can use hyperlinks for more information if needed. Students could summarise key topic areas such as how vaccines are made, how they are used to eliminate disease as well as information about each vaccine and the disease it controls. Gram staining activity brainpop provide a virtual lab where students can carry out Gram staining on-line to test a contaminated yogurt sample. Students can practise Gram staining either as a preparatory homework or lesson starter to allow them to practise the steps required for the procedure. This could be used for students to plan their own method prior to carrying out the procedure. 7

8 Thinking Conceptually Approaches to teaching the content Two contrasting routes through the specification content are suggested over the following pages. They are: Conceptual Route Ethical Route The ethical route highlights the distinctions between two very different types of content: the technical detail of epidemiology and its causal agents, and the open-ended range of its ethical judgements. Detail, precision and rigour are necessary to fully understand the processes, but imagination and maturity are necessary to appreciate the applications and their relevance to society. Freedom to innovate and explore are encouraged in the interactive contextual resources provided. Conceptual Route This builds up from the basic structure of the pathogens and leads on from the prevention of disease in society to the treatment of infection and the associated risks in a hospital environment. It would suit able students with a good background in molecular biology and an ability to clearly sequence actions. Teaching Aims Content Outline unless stated otherwise Revise the ultrastructure of a typical eukaryotic plant cell and a prokaryotic cell, as visible under an electron microscope Revise the structure of a typical virus Revise how pathogens cause communicable disease State the principles of vaccination Illustrate the biological problems in the development of vaccines Describe the use of vaccination programmes Consider specifically the vaccination programme used in the United Kingdom Outline the role of HPV vaccination in the United Kingdom Identify and discuss the ethical issues related to the development and use of vaccines Describe the action of antibiotics in the treatment of communicable disease Consider how the misuse of antibiotics can cause the development of resistant strains of bacteria Revise the use of Gram stain to identify bacteria Revise the culturing of bacteria to identify Gram-positive and Gram-negative cultures Carry out a practical investigation into the effect of antibiotics on Gram-positive and Gram-negative bacteria Investigate the preventative measures taken to reduce the spread of resistant bacteria in hospitals (h) (i) and (h) (ii) 3.2.1(c) 3.2.1(a) (a) (c) (c) (b) (b) (d) (e) (f ) (d) (ii) (d) (i) (g) (g) 8

9 Thinking Conceptually Ethical Route This route starts by exciting students with the impact that communicable diseases have on society, the advances that medicine has made in controlling the spread of such diseases and the fight back these diseases are having against medicine such as Methicillin Resistant Staphylococcus aureus and Clostridium difficile. It would suit students with a humanities background who are more likely to engage if the content relevant to society is presented first. Newspaper articles, web based news sites or the NHS website can be used to ignite discussion of communicable diseases. Teaching Aims Content Outline unless stated otherwise In groups revise the social, ethical, economic and biological factors involved in the attempts to control and prevent diseases Research the precautions taken to reduce the spread of resistant bacteria in hospitals Discuss how pathogens cause communicable diseases Outline the modes of action of antibiotics on bacteria Outline the use of antibiotics in the treatment of communicable diseases (i) (g) 3.2.1(a) (g) (e) Explain how the misuse of antibiotics can lead to the evolution of resistant strains of bacteria Revise the use of Gram stain to identify bacteria Revise the culturing of bacteria to identify Grampositive and Gram-negative cultures Practically investigate the effect of antibiotics on Gram-positive and Gram-negative bacteria Extend the investigation on Gram-positive and Gram-negative bacteria by investigating the effects of antibacterial hand washes Provide a forum for the ethical issues related to the development and use of vaccines particularly those for children State the principles of vaccination Discuss the biological problems in developing vaccines Consider the role of vaccination programmes in the prevention of epidemics Outline the role of HPV vaccination in the United Kingdom Discuss the attitude of society to the role of vaccination programmes Outline the programme of vaccination used in the United Kingdom (f ) (d) (ii) (d) (i) (g) (g) (d) (a) (c) (b) (b) (c) (b) 9

10 Thinking Conceptually Common misconceptions or difficulties students may have Understanding the complexity of antibiotic resistance development and the role of vaccination is made much simpler if students have a firm grasp of cellular biology, in particular prokaryotic cell and viral structure. The ethical dimension to decision-making about vaccination and its role in society often finds students unprepared in exams. It is important that students have a clear understanding of the idea of ethical as meaning morally right, and that they are used to assessing moral rights and wrongs without resorting to clichés. The other major difficulty students encounter is not appreciating the evolution of antibiotic resistant bacteria and its impact on causing disease. This is specifically addressed in both teaching routes set out above. Conceptual links to other areas of the specification useful ways to approach this topic to set students up for topics later in the course. Teaching of this topic should be firmly bedded in an understanding of the social, ethical, economic and biological factors involved in the attempts to control and prevent diseases (i) and how pathogens cause communicable disease (a). A secure grasp of the prokaryotic cell structure, (h) (i), is also needed. The concepts learned in are relevant to the following areas of the syllabus and a link could be made back to the older topic and the material re-introduced in the later topics in order to prepare students for synoptic questions. AS and A Level (e) how the incidence and prevalence of disease can change over time (f ) calculations of incidence rates and prevalence rates, mortality rates and their importance in epidemiology (g) the analysis, interpretation and use of epidemiological data A Level only (a) the factors that alter the birth rate and death rate in human populations (b) gene mutations only (a) the role of natural selection in changing allele frequencies within populations 5.1.2(b) the link between the changes in the amino acid sequence to the change in structure and properties of proteins 10

11 Thinking Conceptually Activities Resources Evolution of antibiotic resistant bacteria animation The misuse of antibiotics leading to the evolutionary process of antibiotic resistance is explained in a narrated or step through format. The mode of action of antibiotics is explained along with their impact on the bacteria as a process of natural selection. There is an option to have the animation narrated so it can be used in class for teaching or by individual students with access to a computer in a class or private study setting. Accompanying activities could involve written summaries or translating the information into another form such as a flow chart to cement learning and understanding. Hand wash investigation The following resource can be used to inform students of the correct hand washing technique: A range of handwashes can then be used prior to deliberately contaminating nutrient agar plates (relates to PAG7). A similar investigation could be carried out with a serial dilution of a single hand wash (relates to PAG7). 11

12 Thinking Conceptually Activities Resources Carrying out Gram staining Laboratory applications in microbiology provide a step by step animation showing the steps of gram staining. If used online the students can test themselves using the test yourself questions that follow the animation. A more detailed video tutorial can be used if the students are to be guided through the practical step by step. Students should be supplied with pre-prepared bacterial colonies or could produce their own as part of the Hand wash investigation. Students should take a sample of the bacterial colony using aseptic technique (PAG3). They can then carry out Gram staining to identify gram-positive and gram-negative bacteria (PAG1). Extension: Statistical analysis of results to determine whether handwashes are more or less effective on Gram-ve rather than Gram+ve (Maths Skill M1.9) Key facts on vaccines Vaccines Europe provide a comprehensive overview of what a vaccine is, types of vaccine, how vaccines work and how vaccines are produced. Students could research each aspect and collate their findings to produce an information booklet on vaccines or each topic could be researched independently by a group who could then present their findings to the rest of the class. 12

13 Thinking Contextually ACTIVITIES Activities Interactive materials detailing the use of vaccination and the development of antibiotic resistant bacteria are listed below. A useful broad context in which to begin to understand the impact of antibiotic resistant bacteria evolution along with the methods attempting to control it is to consider the documentary Rise of the Superbugs. The social context of Extensive Drug resistant TB in the documentary allows students to develop interests and curiosity into the development and impact of the pathogen. The video can be found at any of these sites: Rise of the superbugs provides a TB-led context for exploring antibiotic resistance and relating it to the advances in medicine. This can be used with resources from Big Picture Education to allow students to analyse a case study and provide a comprehensive review with ethical considerations. The documentary is almost 45 minutes long but provides a fascinating insight into the development of drug resistant diseases and a look at how scientific research and hospitals operate, which will be of particular interest to year 13 students. Resources 13

14 Thinking Contextually Activities Resources Human vs Superbugs BBC iwonder site The resource gives a broad introduction into how antibiotic resistance develops through to how the advance in resistance may be halted. Select each section to receive thought-provoking diagrams, video clips and animations. The areas covered include: how antibiotic resistance develops, human impact on antibiotic resistance, how the problem is being tackled and potential future solutions. A suggested activity after exploring the resources is to produce a drug information flyer illustrating the importance of completing a course of antibiotics and the potential consequences of not doing so. Beginning of vaccination Science channel This resource gives a brief introduction into how the first vaccine was produced by Edward Jenner in The clip gives a brief overview of the discovery of vaccination. This resource gives details of the battle against disease and the success of vaccination in chronological order. After watching the clip and researching the timeline students could produce a newspaper article from 1796 detailing what has been discovered and what it could potentially mean for the future. Vaccine production The history of vaccination The resource gives a comprehensive overview of the different types of vaccine and the pathogens for which they are used. Students could work in small groups to produce a summary of one of the types of vaccination and then present their findings to the class. A worksheet could then be drawn up as a table with column headings detailing the pro s and con s of each method of vaccination. 14

15 Thinking Contextually Activities Human Papilloma virus NHS The resources give a comprehensive overview of what HPV is and some of its potential consequences. The second resource gives greater details of the consequences of contracting HPV A suggested activity is to divide the class into two groups who should use the resources to plan a for and against ethical debate. As these are publicity materials to encourage the use of HPV vaccination they are by nature easier to use to support the for argument and so could be used to differentiate for a less able group with the against argument being used for the more able. HSW10 Resources Pandemic and Plague inc. These resources are video games built on simulations of epidemic disease spread. They both allow students to create pathogens and see how specific mutations affect the spread of the disease. Pandemic allows game play at two levels (Relaxed and Realistic) and gives the students the choice of a range of pathogens with which they can try and cause a pandemic across the world in a short time frame. The instructional guide allows the participation of students with less experience in computer gaming to try and infect the world with their pathogen. Plague inc. has a more polished, commercial feel and is not free. It is available as an app for ipad, iphone and Android. The combination of watching the global spread of a disease, and the link with the microscopic, mutational changes of the pathogen is thought-provoking. 15

16 Thinking Contextually Activities Ebola The resource is a factsheet that gives students a comprehensive description of the problem Ebola virus poses by thoroughly explaining the symptoms, mode of transmission, treatments and vaccines, and methods of prevention and control. The second resource includes a number of reviews into the spread of the Ebola virus over the first 6 months of the epidemic. They give details of the impact Ebola is having on the different countries along with the attempts to control the spread of the disease. The suggested activity using resource one is to produce an information leaflet that could be handed out to the general public if the Ebola virus spread to Britain. The resource should be simple enough to get the points across but still explain a comprehensive range of control measures. One of the reviews in the second resource could be used by the students to produce a short newspaper article on Ebola virus and the attempts at a vaccination programme. These could them be collated to produce an Ebola Fact file. There is also an excellent BBC Horizon special: Ebola The Search for a Cure. First broadcast on BBC2 10/09/2014. Free iplayer availability may be limited. Resources 16

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