This detailed lesson describes the pressure changes that occur during the cardiac cycle and explains how ECG traces can be interpreted. The PowerPoint and accompanying resources have been designed to cover points 4.4 (iii) & (v) of the Edexcel A-level Biology B specification and focuses on the importance of the valves in ensuring unidirectional movement of blood during the cycle. The start of the lesson introduces the cardiac cycle as well as the key term systole, so that students can immediately recognise that the three stages of the cycle are atrial and ventricular systole followed by diastole. Students are challenged on their prior knowledge of the structure of the heart as they have to name and state the function of an atrioventricular and semi-lunar valve from an internal diagram. This leads into the key point that pressure changes in the chambers and the major arteries results in the opening and closing of these sets of valves. Students are given a description of the pressure change that results in the opening of the AV valves and shown where this would be found on the graph detailing the pressure changes of the cardiac cycle. They then have to use this as a guide to write descriptions for the closing of the AV valve and the opening and closing of the semi-lunar valves and to locate these on the graph. By providing the students with this graph, the rest of the lesson can focus on explaining how these changes come about. Students have to use their current and prior knowledge of the chambers and blood vessels to write 4 descriptions that cover the cardiac cycle. The final part of the lesson covers the changes in the volume of the ventricle. The remainder of the lesson focuses on the ECG and explains how these traces can be interpreted to diagnose heart problems. A quiz competition is used to introduce the reference points of P, QRS and T on a normal sinus rhythm before time is taken to explain their representation with reference to the cardiac cycle. Moving forwards, a SPOT the DIFFERENCE task is used to challenge the students to recognise differences between sinus rhythm and some abnormal rhythms including tachycardia and atrial fibrillation. Bradycardia is used as a symptom of sinus node disfunction and the students are encouraged to discuss this symptom along with some others to try to diagnose this health problem.

This lesson describes the meaning of ecological terms and explains how biotic and abiotic factors control the distribution of organisms in a habitat. The engaging PowerPoint and accompanying resources have been designed to cover points 5.11, 5.12 and 5.13 in unit 4 of the Edexcel International A-level Biology (Salters Nuffield) specification and therefore cover the biological definitions of ecosystem, community, population and habitat. A quiz round called REVERSE Biology Bingo runs throughout the lesson and challenges students to recognise the following key terms from descriptions called out by the bingo caller: community ecosystem abiotic factor photosynthesis respiratory substrate biomass calorimetry distribution niche The ultimate aim of this quiz format is to support the students to understand that any sugars produced by photosynthesis that are not used as respiratory substrates are used to form biological molecules that form the biomass of a plant and that this can be estimated using calorimetry. Links are made to photosynthesis and net primary productivity as these will be met later in topic 5 as well as challenging their prior knowledge of adaptations, heterozygosity index classification and biological molecules. The final part of the lesson uses an exam-style question to get the students to recognise that biotic and abiotic factors control the distribution of organisms in a habitat and to recall the concept of niche.

This fully-resourced lesson describes the major routes that pathogens take when entering the body and the body’s barriers to this infection. The engaging and detailed PowerPoint and accompanying resources have been designed to cover points 6.7 (i) & (ii) of the Edexcel International A-level Biology specification and includes descriptions of the following barriers: skin the blood clotting process mucous membranes stomach acid vaginal acid and flora skin and gut flora wax in the ear canal There are clear links to topics 1, 2 and 3 in each of these barriers, so these are considered and discussed during each of the descriptions. For example, the presence of keratin in the cytoplasm of the skin cells allows the student knowledge of the properties of this fibrous protein to be checked. Other topics that are revisited during this lesson include protein structure, key terminology and the epithelium that lines the different parts of the airways. All of the exam-style questions have mark schemes that are embedded into the PowerPoint and a number of the tasks have been differentiated to allow students of differing abilities to access the work.

This lesson describes the principles of ex situ conservation and discusses the advantages and issues surrounding this method. The PowerPoint and accompanying worksheet are part of the second lesson in a series of 2 which have been designed to cover the content of point 3.3 (iii) of the Edexcel A-level Biology B specification and it closely ties in with the previous lesson on in situ conservation. To enrich their understanding of ex situ conservation, the well-known examples of ZSL London zoo, Kew Gardens and the Millennium Seed Bank Project in Wakehurst are used. Students will understand how conserving animal species outside of their natural habitat enables human intervention that ensures the animals are fed and given medical assistance when needed as well as reproductive assistance to increase the likelihood of the successful breeding of endangered species. As with the in situ method in the previous lesson, the issues are also discussed and there is a focus on the susceptibility of captive populations to diseases as a result of their limited genetic diversity. The final part of the lesson considers how seed banks can be used to ensure that plant species avoid extinction and how the plants can be bred asexually to increase plant populations quickly.

This lesson describes how the standard deviation and the t-test are used to analyse data. The detailed PowerPoint and accompanying resources are part of the first lesson in a series of 2 lessons that have been designed to cover point 10.1 (vi) of the Edexcel A-level Biology B specification. The next lesson, which uses skills covered in this lesson and has also been uploaded, describes how to analyse data using the Spearman rank correlation coefficient A step by step guide walks the students through each stage of the calculation of the standard deviation and gets them to complete a worked example with the class before applying their knowledge to another set of data. This data looks at the birth weights of humans on one day in the UK and this is used again later in the lesson to compare against the birth weights of babies in South Asia when using the student’s t-test. The null hypothesis is re-introduced, as it will encountered when considering the chi squared test in topic 8, and students will learn to accept or reject this based upon a comparison of their value against one taken from the table based on the degrees of freedom.

This lesson evaluates the methods used by zoos and seed banks in the conservation of endangered species. The PowerPoint and accompanying resources have been primarily designed to cover point 4.16 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification but as this is potentially the last lesson in this topic, lots of questions and activities have been included that will challenge the students on their knowledge of topic 4 (Biodiversity and Natural Resources). Hours of research went into the planning of this lesson to source interesting examples to increase the relevance of the biological content and although the main focus of the lesson is the two ex situ conservation methods, the lesson begins with a consideration of the importance of the in situ methods that are used in the Lake Télé Community reserve in the Republic of Congo and the marine conservation zone in the waters surrounding Tristan da Cunha. Students will learn how this form of active management conserves habitats and species in their natural environment, with the aim of minimising human impact whilst maintaining biodiversity. To enrich their understanding of ex situ conservation, the well-known examples of ZSL London zoo, Kew Gardens and the Millennium Seed Bank Project in Wakehurst are used. Students will understand how conserving animal species outside of their natural habitat allows for human intervention that ensures the animals are fed and given medical assistance when needed as well as reproductive assistance to increase the likelihood of the successful breeding of endangered species. An emphasis is placed on the desire to reintroduce the species into the wild and the example of some initial successes with the mountain chicken frog in Dominica and Montserrat is discussed. As stated in the specification point, these methods must be evaluated and therefore the issues are also considered and there is a focus on the susceptibility of captive populations to diseases as a result of their limited genetic diversity. The final part of the lesson considers how seed banks can be used to ensure that plant species, which may contain the molecules for medicine development, avoid extinction, and how the plants can be bred asexually to increase plant populations quickly. Due to the extensiveness of this lesson, it is estimated that it will take in excess of 2/3 hours of allocated A-level teaching time to cover the tasks and content included in the lesson and as explained above, it can also be used as revision of topic 4 content

This lesson explains the difference between non-infectious and infectious diseases and names the pathogens that cause examples of the latter. The PowerPoint and accompanying worksheets have been primarily designed to cover points 10.1 (a & b) of the CIE A-level Biology specification but as this is the first lesson in topic 10, links to upcoming topics such as the immune response and vaccinations are introduced. The lesson begins with a challenge where the students have to use descriptions to recognise CHD, HIV and TB as diseases that are commonly referred to by their abbreviations. This leads into a description of the meaning of disease before the students are challenged to use any prior knowledge of this topic to recognise that CHD is an examples of a non-infectious disease whereas HIV and TB are examples of infectious diseases. Specification point 10.1 (a) states that students should know about sickle cell anaemia and lung cancer so the next section of the lesson focuses on the key details of these diseases and when considering the former, their knowledge of gene mutations, protein synthesis and haemoglobin is tested. viruses - HIV/AIDS, influenza, measles, smallpox bacteria - TB, cholera, protoctista - malaria The infectious diseases shown above are covered by the remainder of this lesson and the differing mechanisms of action of these three types of pathogens are discussed and considered throughout. For example, time is taken to describe how HIV uses a glycoprotein to attach to T helper cells whilst toxins released by bacteria damage the host tissue and the Plasmodium parasite is transmitted from one host to another by a vector to cause malaria. The accompanying worksheets contain a range of exam-style questions, including a mathematical calculation, and mark schemes are embedded into the PowerPoint to allow students to immediately assess their understanding.

This lesson describes the different types of pathogens that can cause communicable diseases in plants and animals. The PowerPoint and accompanying worksheets have been primarily designed to cover point 4.1.1 (a) of the OCR A-level Biology specification but as this is the first lesson in module 4, it has been specifically planned to make links to upcoming topics such as phagocytosis, vaccinations and classification. viruses - HIV/AIDS, influenza, TMV bacteria - TB, cholera, ring rot protoctista - malaria fungi - athlete’s foot, black sigatoka, ringworm, The diseases shown above are covered by the detailed content of this lesson and the differing mechanisms of action of the four types of pathogens are discussed and considered throughout. For example, time is taken to describe how HIV uses a glycoprotein to attach to T helper cells whilst toxins released by bacteria damage the host tissue and the Plasmodium parasite is transmitted from one host to another by a vector to cause malaria. The accompanying worksheets contain a range of exam-style questions, including a mathematical calculation, and mark schemes are embedded into the PowerPoint to allow students to immediately assess their understanding.

This lesson outlines how bacteria become resistant to antiobiotics and discusses its consequences and the steps taken to reduce its impact. The PowerPoint and accompanying worksheet have been designed to cover specification points 10.2 (b & c) of the CIE A-level Biology specification President Trump’s error ridden speech about antibiotics is used at the beginning of the lesson to remind students that this is a treatment for bacterial infections and not viruses as he stated. Moving forwards, 2 quick quiz competitions are used to introduce MRSA and then to get the students to recognise that they can use this abbreviation to remind them to use mutation, reproduce, selection (and survive) and allele in their descriptions of the development of resistance by evolution through natural selection. The main task of the lesson challenges the students to form a description to explain how this strain of bacteria developed resistance to methicillin, making use of the five key terms emphasised above. Moving forwards, there is a focus on the hospital as the common location for MRSA infections and students will recognise that this opportunistic pathogen can infect through open wounds to cause sepsis and potentially death. Figures from infections and deaths in hospitals in the US are used to increase the relevance and students will learn how a MRSA prevention program in VHA facilities includes screening of surgery patients to try to reduce its impact. The lesson concludes with a discussion about other methods that can be used by hospitals and general practitioners to reduce the impact of MRSA and to try to prevent the development of resistance in other strains.

This fully-resourced lesson describes the process of skeletal muscle contraction in terms of the sliding filament theory. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 7.2 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and includes the role of actin, myosin, troponin, tropomyosin, calcium ions and ATP. The lesson begins with a study of the structure of the thick and thin filaments. Students will recognise that the protruding heads of the myosin molecule are mobile and this enables this protein to bind to the binding sites when they are exposed on actin. This leads into the introduction of troponin and tropomyosin and key details about the binding of calcium to this complex is explained. Moving forwards, students are encouraged to discuss possible reasons that can explain how the sarcomere narrows during contraction when the filaments remain the same length. This main part of the lesson goes through the main steps of the sliding filament model of muscle contraction and the critical roles of the calcium ions and ATP are discussed. The final task of the lesson challenges the students to apply their knowledge by describing the immediate effect on muscle contraction when one of the elements doesn’t function correctly. This lesson has been written to tie in with another uploaded lesson on the structure of a muscle fibre which is covered in specification point 7.10

This detailed and fully-resourced lesson describes and explains the pressure changes in the heart and arteries and the role of the valves movements in the cardiac cycle. The PowerPoint and accompanying resources have been designed to cover point 3.1.2 (f) of the OCR A-level Biology A specification and also covers the use of the equation stroke volume x heart rate to calculate cardiac output The start of the lesson introduces the cardiac cycle as well as the key term systole, so that students can immediately recognise that the three stages of the cycle are atrial and ventricular systole followed by diastole. Students are challenged on their prior knowledge of the structure of the heart as they have to name and state the function of an atrioventricular and semi-lunar valve from an internal diagram. This leads into the key point that pressure changes in the chambers and the major arteries results in the opening and closing of these sets of valves. Students are given a description of the pressure change that results in the opening of the AV valves and shown where this would be found on the graph detailing the pressure changes of the cardiac cycle. They then have to use this as a guide to write descriptions for the closing of the AV valve and the opening and closing of the semi-lunar valves and to locate these on the graph. By providing the students with this graph, the next part of the lesson can focus on explaining how these changes come about. Students have to use their current and prior knowledge of the chambers and blood vessels to write 4 descriptions that cover the cardiac cycle. Moving forwards, the students are introduced to the stroke volume and meet normative values for this and for resting heart rate. This will lead into the calculation for cardiac output and a series of questions are used to test their ability to apply this equation as well as to calculate the percentage change which is a commonly assessed mathematical skill. This lesson has been written to tie in with the other uploaded lessons on the topics detailed in module 3.1.2 (Transport in animals)

This engaging lesson covers the biological classification of a species, phylogenetic classification and the use of the binomial naming system. The PowerPoint and accompanying resources have been designed to cover point 4.5 of the AQA A-level Biology specification which is titled species and taxonomy. The lesson begins by looking at the meaning of a population in Biology so that the term species can be introduced. A hinny, which is the hybrid offspring of a horse and a donkey, is used to explain how these two organisms must be members of different species because they are unable to produce fertile offspring. Although the art of courting might be lost on humans in the modern world, the marabou stork is used as an example to show how courtship behaviour is an essential precursor to successful mating in most organisms. Students are encouraged to discuss other examples of courtship behaviour, such as the release of pheromones and birdsong, so that their knowledge and understanding is broad. Moving forwards, students will learn that species is the lowest taxon in the modern-day classification hierarchy. A quiz runs throughout the lesson and this particular round will engage the students whilst they learn the names of the other 7 taxa and the horse and the donkey from the earlier example are used to complete the hierarchy. Students will understand that the binomial naming system was introduced by Carl Linnaeus to provide a universal name for each species and they will be challenged to apply their knowledge by completing a hierarchy for a modern-day human, by spotting the correct name for an unfamiliar organism and finally by suggesting advantages of this system. The final part of the lesson briefly looks at how advances in genome sequencing and the comparison of common biological molecules has allowed the relationships between organisms to be clarified. This is a detailed lesson and it is estimated that it will take around 2 hours of A-level teaching time to cover the content and therefore this specification point.

This fully-resourced lesson explains how gel electrophoresis is used to analyse nucleic acids and proteins and explores its applications in forensic science and medical diagnosis. The engaging and detailed PowerPoint and accompanying resource have been written to cover point 19.1 (d) of the CIE International A-level Biology specification As a whole lesson, each step of the genetic fingerprinting process is covered but with the main focus on gel electrophoresis within this process. Students will be introduced to STRs and will come to recognise their usefulness in human identification as a result of the variability between individuals. Moving forwards, the involvement of the PCR and restriction enzymes are discussed and students are challenged on their knowledge of this process and these substances as they were encountered in a previous lesson. The main section of the lesson focuses on the use of gel electrophoresis to separate DNA fragments (as well as proteins) and the key ideas of separation due to differences in base pair length or molecular mass are discussed and explained. As well as current understanding checks, an application question involving Huntington’s disease is used to challenge their ability to apply their knowledge of the process to an unfamiliar situation. The remainder of the lesson describes how the DNA is transferred to a membrane and hybridisation probes are used to create a pattern on the X-ray film. Time has been taken to make continuous links to the previous lessons in topic 19.1 as well as those from topic 6 where DNA, RNA and protein synthesis were introduced.

This lesson explains how the polymerase chain reaction (PCR) is used to clone and amplify DNA fragments as part of the recombinant DNA technology process. The PowerPoint has been designed to cover point 19.1 © of the CIE International A-level Biology specification and there is a particular emphasis on the use of Taq polymerase as opposed to human DNA polymerase A quick quiz competition is used to introduce the PCR abbreviation before students are encouraged to discuss the possible identity of the enzyme involved and to recall the action of this enzyme. Students will learn that this reaction involves cyclical heating and cooling to a range of temperatures so the next part of this lesson focuses on each temperature and specifically the reasons behind the choice. Time is taken to examine the key points in detail, such as why Taq polymerase has to be used as it is not denatured at the high temperature as well as the involvement of the primers. This process is closely linked to other techniques like electrophoresis which is covered in a later lesson and ties are continuously made throughout the lesson

This fully-resourced lesson describes how the structure of the xylem tissue allows water to be transported in the stem and leaves. Written for AQA A-level Biology, the engaging and detailed PowerPoint and the accompanying worksheets cover the 1st part of specification point 3.4.2 (mass transport in plants) and includes a detailed description of the cohesion-tension theory. The first part of the lesson focuses on the relationship between the structure and function of the xylem tissue. A number of quiz competitions have been included in the lesson to maintain engagement and to introduce key terms. The 1st round does just that and results in the introduction of lignin which leads into the explanation of how the impregnation of this substance in the cell walls result in the death and subsequent decay of the cell structures. Students are encouraged to discuss how the formation of this hollow tube enables the transport of water to be effective. Moving forwards, other structures such as the bordered pits are introduced and an understanding of their function is tested later in the lesson. The remainder of the lesson focuses on the transport of water in the stem and leaves by root pressure and the transpiration pull, which includes cohesion, tension and adhesion. The lesson has been designed to make links to information covered earlier in the lesson as well to topics from earlier in the specification such as cell structures and biological molecules Due to the extensiveness of this lesson, it is estimated that it will take in excess of 2/3 A-level teaching hours to cover the detail included in this lesson.