This lesson describes the inheritance of two non-interacting unlinked genes and guides students through the calculation of phenotypic ratios. The PowerPoint and the accompanying question sheet (which is differentiated) have been designed to cover point 8.2 (iii) of the Edexcel A-level Biology B specification. As the previous lesson described the construction of genetic crosses and pedigree diagrams, students are aware of the methods involved in writing genotypes and gametes for the inheritance of a single gene. Therefore, the start of this lesson builds on this understanding to ensure that students recognise that genotypes contain 4 alleles and gametes contain 2 alleles when two genes are inherited. The students are taken through the steps of a worked example to demonstrate the key steps in the calculation of a phenotypic ratio before 2 exam-style questions challenge them to apply their newly-acquired knowledge. Mark schemes are displayed within the PowerPoint to allow students to assess their progress. The phenotypic ratio generated as the answer to the final question is 9:3:3:1 and time is taken to explain that this is the expected ratio when two heterozygotes for two genes are crossed which they may be expected to use when meeting the chi squared test in an upcoming lesson

This lesson describes how to analyse data using the Spearman rank correlation coefficient. The PowerPoint and accompanying exam-style question are part of the second lesson in a series of 2 lessons which have been designed to cover point 10.1 (vi) of the Edexcel A-level Biology B specification. The first lesson in this series described how to analyse data using the standard deviation and the t-test As with the previous lesson, a step by step guide is used to walk the students through the use of the formula to generate the rank coefficient and to determine whether there is a positive correlation, no correlation or a negative correlation. The students are also reminded of the null hypothesis and will be shown how to accept or reject this hypothesis and to determine significance. The students will work through an example with the class and then are given the opportunity to apply their newly-acquired knowledge to an exam-style question. The mark scheme is displayed on the PowerPoint so they can assess their understanding

This lesson describes how random and non-random sampling strategies can be carried out to measure the biodiversity of a habitat. The PowerPoint and accompanying worksheets are part of the first lesson in a series of 2 which have been designed to cover the content of point 4.2.1 (b) (i) of the OCR A-level Biology A specification and this lesson specifically focuses on sampling plant species. The second lesson covers the sampling of animal species using apparatus such as pooters and sweeping nets. The lesson begins with a challenge, where the students have to recognise the terms random and stratified from descriptions that were met in modules 2.1.6 and 3.1.1. This introduces the concept of sampling and emphasises its importance in the measurement of biodiversity and the students will learn that there is random sampling as well as non-random sampling, and that one of these strategies is known as stratified. The next part of the lesson focuses on the random sampling of a habitat where the results found with a quadrat are used to estimate the population of sessile species like plants. Due to the heavy mathematical content in the A-level Biology exams, a step by step guide is used to walk the students through the key stages in these calculations and includes the extra steps needed when the quadrat does not have an area of 1 metre squared. A series of exam-style questions will then challenge them to apply their understanding and mark schemes are embedded in the PowerPoint to allow them to immediately assess their progress. The use of quadrats that have been divided into 100 squares and point frames to estimate percentage ground cover are also discussed and the overall advantages and disadvantages of random sampling are considered. Moving forwards, the stratified, opportunistic and systematic strategies of non-random sampling are discussed and again the advantages and disadvantages of all three are considered. Time is taken to focus on line and belt transects and students will learn that the latter can be particularly useful when an abiotic factor appears to change across a habitat.

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 evaluates the methods used by zoos and seed banks in the conservation of endangered species and their genetic diversity. The PowerPoint and accompanying resources have been primarily designed to cover point 4.21 of the Edexcel International A-level Biology 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 and understanding of topic 4 (Plant structure and function, Biodiversity and Conservation). Hours of research went into the planning of this lesson to source interesting examples and although the main focus of the lesson is the zoo and seed banks as 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 outlines how penicillin acts on bacteria and why antibiotics do not affect viruses. The PowerPoint and accompanying resources have been designed to cover point 10.2 (a) of the CIE A-level Biology specification and also introduces the concept of bactericidal and bacteriostatic antibiotics, as illustrated by penicillin and tetracycline. The lesson begins with an engaging task, where the students have to identify the surnames of famous scientists from their descriptions to reveal the surname Fleming. This introduces Sir Alexander Fleming as the microbiologist who discovered penicillin in 1928. Time is taken to describe penicillin as a group of antibiotics that contain a beta-lactam ring in their molecular structure. Using this information and their knowledge of bacterial cell structure from topic 1, the students have to complete a passage describing how penicillin inhibits the formation of cross links in cell wall synthesis. A series of exam-style questions are then used to make links to the upcoming topic of antibiotic resistance. The next part of the lesson focuses on the differences between bactericidal and bacteriostatic antibiotics and the students will learn that penicillin is bactericidal as the weakening of the cell wall leads to lysis and death. Tetracycline is used as the example of a bacteriostatic antibiotic and students will discover that it is the prevention of the binding of tRNA that inhibits protein synthesis and that this reduction and prevention of growth and reproduction is synonymous with these antimicrobial agents. Students are challenged on their knowledge of translation and will also be given time for a class discussion to understand that these antibiotics work in tandem the body’s immune system to overcome the pathogen The final part of the lesson explains why antibiotics are ineffective against viruses.

This lesson describes the action of bactericidal and bacteriostatic antibiotics, as illustrated by penicillin and tetracycline. The engaging PowerPoint and accompanying resources have been designed to cover point 6.3 (i) of the Edexcel A-level Biology B specification but it has been specifically planned to make continual links to earlier lessons in topic 6 and to protein synthesis as covered in topic 1 The lesson begins by challenging the students to use their general biological knowledge and any available sources to identify the suffixes cidal and static. Students will learn that when the prefix is added, these form the full names of two types of antibiotics. Their understanding of terminology is tested further as they have to recognise that Polymyxin B is an example of a bactericidal antibiotic as its actions would result in the death of the bacterial cell. Time is then taken to describe the action of penicillin and students will learn how inhibitors and modified versions of this antibiotic are used to overcome those bacteria who have resistance. Tetracycline is used as the example of a bacteriostatic antibiotic and students will discover that its prevention of the binding of tRNA that inhibits protein synthesis and this reduction and stopping of growth and reproduction is synonymous with these drugs. Students are challenged on their knowledge of translation and will also be given time for a class discussion to understand that these antibiotics encourage the body’s immune system to overcome the pathogen in natural, active immunity. The final part of the lesson uses a quick quiz competition and a series of exam-style questions to ensure that students can recognise these different types of antibiotics from descriptions.

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 detailed lesson describes how recombinant DNA is produced using restriction endonucleases and DNA ligase and is inserted into other cells. The engaging PowerPoint and accompanying resources have been designed to cover points 8.18 & 8.19 of the Edexcel International A-level Biology specification. The lesson begins with a definition of genetic engineering and recombinant DNA to allow students to begin to understand how this process involves the transfer of DNA fragments from one species to another. Links are made to the genetic code and transcription and translation mechanisms, which were met in topic 2, in order to explain how the transferred gene can be translated in the transgenic organism. Moving forwards, the method involving reverse transcriptase and DNA polymerase is introduced and their knowledge of the structure of the polynucleotides and the roles of enzymes is challenged through questions and discussion points. Restriction endonucleases are then introduced and time is taken to look at the structure of a restriction site as well as the production of sticky ends due to the staggered cut on the DNA. A series of exam-style questions with displayed mark schemes are used to allow the students to assess their current understanding. The second half of the lesson looks at the culture of transformed host cells as an in vivo method to amplify DNA fragments. Students will learn that bacterial cells are the most commonly transformed cells so the next task challenges their recall of the structures of these cells so that plasmid DNA can be examined from that point onwards. Time is taken to explore the finer details of each step such as the addition of the promoter and terminator regions, use of the same restriction enzyme to cut the plasmid as was used to cut the gene and the different types of marker genes. As well as understanding and prior knowledge checks, quick quiz competitions are used throughout the lesson to introduce key terms such as cDNA and EcoR1 in a fun and hopefully memorable way

This lesson explains how a nerve impulse (action potential) is conducted along an axon and focuses on the role of the sodium and potassium ions. The PowerPoint and accompanying resources have been designed to cover point 8.4 of the Edexcel International A-level Biology specification and contains detailed descriptions of resting potential, depolarisation, repolarisation, hyperpolarisation and the refractory period. This topic is commonly assessed in the terminal exams so extensive planning ensures that this resource includes a wide range of activities to motivate and engage the students whilst ensuring that the content is covered in the depth of detail that will allow them to have a real understanding. Interspersed within the activities are understanding checks and prior knowledge checks to enable the students to not only assess their progress against the current topic but also to challenge themselves on the links to earlier topics such as methods of movements across cell membranes. There are also a number of quiz competitions which are used to introduce key terms and values in a fun and memorable way and discussion points to encourage the students to consider why a particular process or mechanism occurs. Over the course of the lesson, the students will learn and discover how the movement of ions across the membrane causes the membrane potential to change. They will see how the resting potential is maintained through the use of the sodium/potassium pump and potassium ion leakage. There is a real focus on depolarisation to allow students to understand how generator potentials can combine and if the resulting depolarisation then exceeds the threshold potential, a full depolarisation will occur. At this point in the lesson students will discover how the all or nothing response explains that action potentials have the same magnitude and that instead a stronger stimulus is linked to an increase in the frequency of the transmission. The rest of the lesson challenges the students to apply their knowledge to explain how repolarisation and hyperpolarisation result and to suggest advantages of the refractory period for nerve cells.

This lesson describes the development and spread of antibiotic resistance in bacteria and discusses the difficulties in controlling this spread. The PowerPoint and accompanying worksheet have been designed to cover specification points 6.4 (i & ii) of the Edexcel A-level Biology B 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 spread of MRSA and to try to prevent the development of resistance in other strains.

This lesson describes the main stages of mitosis and explains the significance of this type of nuclear division for the daughter cells produced by the cycle. The PowerPoint and accompanying resources have been designed to cover points 6 (a & b) in topic 6 of AS unit 1 of the WJEC A-level Biology specification and the process of cytokinesis is also described. Depending upon the exam board taken at GCSE, the knowledge and understanding of mitosis will differ considerably between students and there may be a number of misconceptions. This was considered at all points during the planning of the lesson so that existing errors are addressed and key points are emphasised throughout. Their understanding of interphase is challenged at the start of the lesson to ensure that they realise that it is identical pairs of sister chromatids that enter the M phase. The main part of the lesson focuses on prophase, metaphase, anaphase and telophase and describes how the chromosomes behave in these stages. There is a focus on the centrioles and the spindle fibres that they produce which contract to drag one chromatid from each pair in opposite directions to the poles of the cell. The remainder of the lesson is a series of understanding and application questions where students have to identify the various roles of mitosis in living organisms as well as tackling a Maths in a Biology context question. The lesson concludes with a final quiz round of MITOSIS SNAP where they only shout out this word when a match is seen between the name of a phase, an event and a picture.

This lesson describes the main stages of meiosis and has a specific focus on those events which contribute to genetic variation. The detailed PowerPoint and accompanying resources have been designed to cover point (d) in topic 6 of AS unit 1 of the WJEC A-level Biology specification and includes description of crossing over, independent assortment, independent segregation and the production of haploid gametes In order to understand how the events of meiosis like crossing over and independent assortment and independent segregation can lead to variation, students need to be clear in their understanding that DNA replication in interphase results in homologous chromosomes as pairs of sister chromatids. Therefore the beginning of the lesson focuses on the chromosomes in the parent cell and this first part of the cycle and students will be introduced to non-sister chromatids and the fact that they may contain different alleles which is important for the exchange that occurs during crossing over. Time is taken to go through this event in prophase I in a step by step guide so that the students can recognise that the result can be new combinations of alleles that were not present in the parent cell. Moving forwards, the lesson explores how the independent assortment and segregation of chromosomes and chromatids during metaphase I and II and anaphase I and II respectively results in genetically different gametes. The key events of all of the 8 phases are described and there is a focus on key terminology to ensure that students are able to describe genetic structures in the correct context. The final part of the lesson looks at the use of a mathematical expression to calculate the possible combinations of alleles in gametes as well as in a zygote following the random fertilisation of haploid gametes. Understanding and prior knowledge checks are interspersed throughout the lesson as well as a series of exam-style questions which challenge the students to apply their knowledge to potentially unfamiliar situations. This lesson has been specifically planned to lead on from the previous two lessons on the cell cycle and the main stages of mitosis and constant references are made throughout to encourage students to make links and also to highlight the differences between the two types of nuclear division