This lesson explains how the polymerase chain reaction (PCR) is used to amplify DNA. The PowerPoint has been designed to cover point 6.17 of the Edexcel International A-level Biology specification. A quick quiz competition is used to introduce the PCR abbreviation before students are encouraged to discuss the 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 looks at these particular temperatures so the important parts of each of the steps can be understood. Time is taken to examine the key points in detail, such as the specific DNA polymerase that is used and how it is not denatured at the high temperature as well as the involvement of the primers.

This lesson describes how individuals may develop immunity, focusing on the different types that are active, passive, natural and artificial. The engaging PowerPoint and accompanying resources have been designed to cover point 6.1 of the Edexcel International A-level Biology specification and there is also a description and discussion of herd immunity to increase the relevance to the current epidemic with COVID-19. The lesson begins with a series of exam-style questions which challenge the students to demonstrate and apply their understanding of the immune response as covered in the previous lessons in this topic. In answering and assessing their answers to these questions, the students will recognise the differences between the primary and secondary immune responses and then a discussion period is included to encourage them to consider how the production of a larger concentration of antibodies in a quicker time is achieved. The importance of antibodies and the production of memory cells for the development of immunity is emphasised and this is continually referenced as the lesson progresses. The students will learn that this response of the body to a pathogen that has entered the body through natural processes is natural active immunity. Moving forwards, time is taken to look at vaccinations as an example of artificial active immunity. Another series of questions focusing on the MMR vaccine will challenge the students to explain how the deliberate exposure to antigenic material activates the immune response and leads to the retention of memory cells. A quick quiz competition is used to introduce the variety of forms that the antigenic material can take along with examples of diseases that are vaccinated against using these methods. The eradication of smallpox is used to describe the concept of herd immunity and the students are given time to consider the scientific questions and concerns that arise when the use of this pathway is a possible option for a government. The remainder of the lesson looks at the different forms of passive immunity and describes the drawbacks in terms of the need for a full response if a pathogen is re-encountered.

This fully-resourced lesson describes the differences between the roles of the B cells and T cells in the body’s immune response. The PowerPoint and accompanying resources have been designed to cover points 6.9 & 6.10 in unit 4 of the Edexcel International A-level Biology specification and includes descriptions of the role of the antigens and the production of antibodies by plasma (effector) cells In the previous lesson on the non-specific responses, the students were introduced to macrophages and dendritic cells as antigen-presenting cells and the start of this lesson challenges their recall and understanding of this process. Time is taken to discuss how the contact between these cells and lymphocytes is critical for the initiation of the body’s (specific) immune response. Moving forwards, a quick quiz competition is used to introduce the names of the different T cells that result from differentiation. Their specific roles are described including an emphasis on the importance of the release of cytokines in cell signalling to activate other immune system cells. T memory cells are also introduced so that students can understand their role in immunological memory and active immunity as described in an upcoming lesson. The next part of the lesson focuses on the B cells and describes how clonal selection and clonal expansion results in the formation of memory B cells and effector cells. A series of understanding and application questions are then used to introduce the structure of antibodies and to explain how the complementary shape of the variable region allows the antigen-antibody complex to be formed. The lesson concludes by emphasising that the pathogen will be overcome as a result of the combination of the actions of phagocytes, T killer cells and the antibodies released by the effector cells

This lesson describes the non-specific responses of the body to infection which include inflammation, lysozyme action, interferon and phagocytosis. The detailed PowerPoint and accompanying resources have been primarily designed to cover the content of point 6.8 of the Edexcel International A-level Biology specification but key details such as antigen-presentation are also introduced to prepare students for upcoming lessons on the immune response (6.9 & 6.10). At the start of the lesson, the students are challenged to recall that cytosis is a suffix associated with transport mechanisms and this introduces phagocytosis as a form of endocytosis which takes in pathogens and foreign particles. This emphasis on key terminology runs throughout the course of the lesson and students are encouraged to consider how the start or end of a word can be used to determine meaning. The process of phagocytosis is then split into 5 key steps and time is taken to discuss the role of opsonins as well as the fusion of lysosomes and the release of lysozymes. A series of application questions are used to challenge the students on their ability to make links to related topics including an understanding of how the hydrolysis of the peptidoglycan wall of a bacteria results in lysis. Students will be able to distinguish between neutrophils and monocytes from a diagram and at this point, the role of macrophages and dendritic cells as antigen-presenting cells is described so that it can be used in the next lesson. The importance of cell signalling for an effective immune response is discussed and the rest of the lesson focuses on the release of two chemicals - interferons and histamine. During the interferon section, references are made to a previous lesson on HIV structure and action so students can understand how the release of these signalling proteins helps neighbouring cells to heighten their anti-viral defences. A step by step guide is used to describe the release of histamine in the inflammatory response and the final task challenges students to use this support to form a detailed answer regarding the steps in inflammation.

This fully-resourced lesson describes how Mycobacterium tuberculosis and human immunodeficiency virus infect human cells and cause symptoms. The PowerPoint and accompanying resources have been designed to cover point 6.6 in unit 4 of the Edexcel International A-level Biology specification and ties in closely with the previous lesson where the structure of bacteria and viruses were compared. The lesson begins by ensuring that students recognise that TB is caused by the infection of a species of bacteria known as Mycobacterium tuberculosis and they will challenged to use their knowledge of scientific classification to recall that this pathogen is found in the mycobacteria genus. At this point, the students are told that the cell walls of this genus contain mycolic acids and later in the lesson they will have to work out that this specialist feature enables this pathogen to survive phagocytosis. A series of exam-style questions will challenge their knowledge of the respiratory and immune systems as they can understand how the bacterium travels to the alveoli where it is engulfed by a macrophage. Key terms like granuloma and necrosis are introduced and the sequence of events that occur following the formation of this aggregate of cells is described. The structure of viruses was covered during the previous lesson, so this next part of the lesson starts by challenging the students to recall the capsid, genetic material in the form of viral RNA and the lipid envelope. At this point, the students are introduced to gp120, the glycoprotein which is exposed on the surface of the lipid envelope, as this structure is critical for the entry of the virus into host cells. Students will annotate a basic diagram of HIV with these four structures which also has gp41 labelled. A quick quiz competition introduces the names of the enzymes found inside the capsid Moving forwards, the main task of this part of the lesson describes how HIV binds to the helper T cells, injects its capsid and integrates its DNA into the host’s genome in order to replicate to form virus particles (virions). Students are guided through the formation of a detailed answer about the mechanism of HIV and have to input key terms and structures where information is missing. Students will learn that the increase in the number of virus particles and a decrease in helper T cells and other immune cells results in infections like TB and by opportunistic pathogens and that this stage is recognised as AIDS

This lesson describes how the products of the light-independent reactions of photosynthesis are used by plants, animals and other organisms. The engaging and detailed PowerPoint and accompanying resources have been primarily designed to cover point 5.4 (ii) of the Edexcel International A-level Biology specification concerning the uses of GP and GALP but as the lesson makes continual references to biological molecules, it can act as a revision tool for a lot of the content of topic 1 and 2. The previous lesson described the light-independent reactions and this lesson builds on that understanding to demonstrate how the intermediates of the cycle, GP and GALP, are used. The start of the lesson challenges the students to identify two errors in a diagram of the cycle so that they can recall that most of the GALP molecules are used in the regeneration of ribulose bisphosphate. A quiz version of Pointless runs throughout the lesson and this is used to challenge the students to recall a biological molecule from its description. Once each molecule has been revealed, time is taken to go through the details of the formation and synthesis of this molecule from GALP or from GP in the case of fatty and amino acids. The following molecules are considered in detail during this lesson: glucose (and fructose and galactose) sucrose starch and cellulose glycerol and fatty acids amino acids nucleic acids A range of activities are used to challenge their prior knowledge of these molecules and mark schemes are always displayed for the exam-style questions to allow the students to assess their understanding. As detailed above, this lesson has been specifically written to tie in with the earlier lessons in this topic on the structure of the chloroplast and the light-dependent and light-independent reactions of photosynthesis

This lesson describes the light-independent reactions of photosynthesis as the reduction of carbon dioxide using the products of the light-dependent reactions. The detailed PowerPoint and accompanying resources have been designed to cover point 5.4 (i) of the Edexcel International A-level Biology specification and this means that it describes carbon fixation in the Calvin cycle and the roles of GP, GALP, RuBP and RUBISCO. The lesson begins with an prior knowledge check where the students are challenged to recall the names of structures, substances and reactions from the light-dependent stage in order to reveal the abbreviations of the main 3 substances in the light-independent stage. This immediately introduces RuBP, GP and GALP and students are then shown how these substances fit into the cycle. The main section of the lesson focuses on the three phases of the Calvin cycle and time is taken to explore the key details of each phase and includes: The role of RUBISCO in carbon fixation The role of the products of the light-dependent stage, ATP and reduced NADP, in the reduction of GP to GALP The use of the majority of the GALP in the regeneration of RuBP . A step-by-step guide, with selected questions for the class to consider together, is used to show how 6 turns of the cycle are needed to form the GALP that will then be used to synthesise 1 molecule of glucose. A series of exam-style questions are included at appropriate points of the lesson and this will introduce limiting factors as well as testing their ability to answer questions about this stage when presented with an unfamiliar scientific investigation. The mark schemes are included in the PowerPoint so students can assess their understanding and any misconceptions are immediately addressed. This lesson has been specifically written to tie in with the previous lessons on the structure of a chloroplast and the light-dependent reactions as well as the upcoming lesson on the products of the light-independent reactions.

This lesson describes the light-dependent reactions of photosynthesis, including cyclic and non-cyclic photophosphorylation. The detailed PowerPoint and accompanying resources have been designed to cover point 5.3 in unit 4 of the Edexcel International A-level Biology specification and therefore this lesson describes how light energy is trapped by exciting electrons in chlorophyll and the role of these electrons in generating ATP, reducing NADP in photophosphorylation and producing oxygen through photolysis of water. This is a topic which students tend to find difficult so this lesson has been intricately planned to walk them through each of the key reactions in the light-dependent stage. Time is taken to describe the roles of the major protein complexes that are embedded in the thylakoid membrane and this includes the two photosystems, the proton pump and ATP synthase. A series of exam-style questions have been written that link to other biological topics in this course such as cell structure and membrane transport as well as application questions to challenge them to apply their understanding. Some of these resources have been differentiated to allow students of differing abilities to access the work and to be pushed at the same time. Students will learn that there are two pathways that the electron can take from PSI and at the completion of the two tasks which describe each of these pathways, they will understand how ATP is generated in non-cyclic and cyclic fashion. The final task of the lesson asks them to compare these two forms of photophosphorylation to check that they understand when photolysis is involved and reduced NADP is formed. Due to the detail included in this lesson, it is estimated that it will take in excess of 2.5 hours of allocated A-level teaching time to complete

This lesson describes how the hydrolysis of ATP supplies energy for biological processes and how the phosphorylation of ADP requires energy. The PowerPoint has been designed to cover point 5.2 in unit 4 of the Edexcel International A-level Biology specification and also describes how the ATP that is made in the light-dependent stage of photosynthesis, is needed in the light-independent stage. The start of the lesson focuses on the structure of this energy currency and challenges the students to use their knowledge of nucleotides and specifically RNA nucleotides to recognise the components of ATP. As a result, they will learn that this molecule consists of adenine, ribose and three phosphate groups. In order to release the stored energy, ATP must be broken down and students will be given time to discuss which reaction will be involved as well as the products of this reaction. Time is taken to describe how the hydrolysis of ATP can be coupled to energy-requiring reactions within cells and the examples of skeletal muscle contraction are used as this is covered in greater detail in topic 7. The final part of the lesson considers how ATP is formed when ADP is phosphorylated and students will learn that this occurs in the mitochondria and chloroplast during aerobic respiration and photosynthesis respectively, so that it ties in with the upcoming lessons in topic 5 and 7.

This fully-resourced lesson describes the the overall reaction of photosynthesis that takes place in the grana and stroma of the chloroplast. The detailed PowerPoint and accompanying resources have been designed to cover points 5.1 & 5.5 in unit 4 of the Edexcel International A-level Biology specification and also describes the relationship between the structure and role of the chloroplast Students will have some knowledge of photosynthesis from iGCSE and were introduced to the ultrastructure of eukaryotic cells in topics 3 and 4 so this lesson has been written to test and to build on that knowledge. A version of the quiz show POINTLESS runs throughout the lesson and this maintains engagement whilst challenging the students to recall the parts of the chloroplast based on a description which is related to their function. The following structures are covered in this lesson: double membrane thylakoids (grana) stroma intergranal lamellae starch grains chloroplast DNA and ribosomes Once each structure has been recalled (or introduced) , a range of activities are used to ensure that key details are understood. As the main focus of the lesson is the reaction of photosynthesis, extra time is taken to introduce the details of the light-dependent and light-independent reactions that take place in the grana and stroma respectively. This includes descriptions of the role of the thylakoid membranes in the light-dependent reactions and the importance of ATP and reduced NADP for the reduction of GP to GALP in the Calvin cycle of the light-independent reactions. Links to other related topics are also made throughout and this is exemplified by the final task of the lesson where students are challenged on their recall of the structure, properties and function of starch (as originally covered in topic 1) As described above, this lesson has been specifically planned to prepare students for the upcoming lessons that cover the details of specification points 5.3 & 5.4 (i) and (ii).

This fully-resourced lesson describes how isolation reduces gene flow between populations which leads to allopatric and sympatric speciation. The engaging PowerPoint and accompanying resources have been designed to cover point 5.24 of unit 4 of the Edexcel International A-level Biology specification and uses a range of real life examples to increase the relevance and to deepen student understanding The lesson begins by using the example of a hinny, which is the hybrid offspring of a horse and a donkey, to challenge students to recall the biological classification of a species. Moving forwards, students are introduced to the idea of speciation and the key components of this process, such as isolation and selection pressures, are covered and discussed in detail. Understanding and prior knowledge checks are included throughout the lesson to allow the students to not only assess their progress against the current topic but also to make links to earlier topics in the specification. Time is taken to look at the details of allopatric speciation and how the different mutations that arise in the isolated populations and genetic drift will lead to genetic changes. The example of allopatric speciation in wrasse fish because of the isthmus of Panama is used to allow the students to visualise this process. The final part of the lesson considers sympatric speciation and again a wide variety of tasks are used to enable a deep understanding to be developed.

This lesson describes how the immune system uses molecules on the surface of a cell to identify it, focusing on the identification of pathogens by their antigens. The PowerPoint and accompanying resources which are differentiated are part of the 1st lesson in the series of 7 that cover the content detailed in topic 2.4 of the AQA A-level Biology specification. As this is the first lesson in topic 2.4, it has been specifically planned to introduce a number of key concepts which include phagocytosis, T and B cells, antibodies and memory cells so that students are prepared for upcoming lessons. The lesson begins by challenging the students to use their knowledge of cells to recall the common internal components of a cell before they are informed that all cells also have molecules on their outer membrane. Students will recognise that these molecules are used by the immune system for identification before a quick quiz competition reveals that this allows toxins, abnormal body cells and pathogens to be identified. Moving forwards, the next part of the lesson focuses on the antigens that are found on the outside of a pathogen and links are made to upcoming lesson topics which include: phagocytosis following the identification of a pathogen antigen-presentation by macrophages and dendritic cells production of antibodies which are specific to the antigens the use of antigens in a vaccination program The final task challenges the students to describe and explain how antigen variability will affect disease and disease prevention and this task has been differentiated two ways to allow students of differing abilities to be challenged and supported.

This lesson describes the key structural features of viruses and challenges the students to compare them against those of a bacteria as covered in topic 3. The PowerPoint and accompanying resource have primarily been designed to cover point 6.5 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification but can be used a revision tool for point 3.4 as students need to recall the structures of a prokaryotic cell. Details of the COVID-19 epidemic are included in the lesson to increase relevance and to help students to understand this biological topic in greater depth. They will understand that a virus’ lack of cell structures results in an non-cellular classification and the fact that it is unable to reproduce without a host is one of the additional reasons that renders it as non-living. The main focus of the lesson is the nucleic acid, the capsid and the attachment proteins that are present in these microorganisms and time is taken to explain how these structures are involved in the infection of a host cell. The lipid membrane is also introduced and links are made to the previous lessons on eukaryotic cells. The final section of the lesson challenges the students to recognise the following prokaryotic cell structures from their descriptions: plasmid pili capsule cell wall flagellum circular DNA ribosomes mesosomes This lesson has been specifically planned to link to the next lesson which covers point 6.6 on the infection of human cells by Mycobacterium tuberculosis and human immunodeficiency virus

This fully-resourced lesson describes how Mycobacterium tuberculosis and Human Immunodeficiency virus infect human cells. The PowerPoint and accompanying resources have been designed to cover point 6.6 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and ties in directly with the previous lesson where the structure of bacteria and viruses were compared. The lesson begins by ensuring that students recognise that TB is caused by the infection of a species of bacteria known as Mycobacterium tuberculosis and they will challenged to use their knowledge of scientific classification to recall that this pathogen is found in the mycobacteria genus. At this point, the students are told that the cell walls of this genus contain mycolic acids and later in the lesson they will have to work out that this specialist feature enables this pathogen to survive phagocytosis. A series of exam-style questions will challenge their knowledge of the respiratory and immune systems as they can understand how the bacterium travels to the alveoli where it is engulfed by a macrophage. Key terms like granuloma and necrosis are introduced and the sequence of events that occur following the formation of this aggregate of cells is described. The structure of viruses was covered during the previous lesson, so this next part of the lesson starts by challenging the students to recall the capsid, genetic material in the form of viral RNA and the lipid envelope. At this point, the students are introduced to gp120, the glycoprotein which is exposed on the surface of the lipid envelope, as this structure is critical for the entry of the virus into host cells. Students will annotate a basic diagram of HIV with these four structures which also has gp41 labelled. A quick quiz competition introduces the names of the enzymes found inside the capsid Moving forwards, the main task of this part of the lesson describes how HIV binds to the helper T cells, injects its capsid and integrates its DNA into the host’s genome in order to replicate to form virus particles (virions). Students are guided through the formation of a detailed answer about the mechanism of HIV and have to input key terms and structures where information is missing. Students will learn that the increase in the number of virus particles and a decrease in helper T cells and other immune cells results in infections like TB and by opportunistic pathogens and that this stage is recognised as AIDS

This fully-resourced lesson describes the relationship between the structure of the chloroplast and its role in the overall reaction of photosynthesis. The detailed PowerPoint and accompanying resources have been designed to cover points 5.5 & 5.9 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and provide a thorough introduction to the light-dependent and light-independent reactions which are covered in the next 3 lessons. Students will have some knowledge of photosynthesis from GCSE and were introduced to the ultrastructure of eukaryotic cells in topics 3 and 4 so this lesson has been written to test and to build on that knowledge. A version of the quiz show POINTLESS runs throughout the lesson and this maintains engagement whilst challenging the students to recall the parts of the chloroplast based on a description which is related to their function. The following structures are covered in this lesson: double membrane thylakoids (grana) stroma intergranal lamellae starch grains chloroplast DNA and ribosomes Once each structure has been recalled (or introduced) , a range of activities are used to ensure that key details are understood. As the main focus of the lesson is the reaction of photosynthesis, extra time is taken to introduce the details of the light-dependent and light-independent reactions that take place in the grana and stroma respectively. This includes descriptions of the role of the thylakoid membranes in the light-dependent reactions and the importance of ATP and reduced NADP for the reduction of GP to GALP in the Calvin cycle of the light-independent reactions. Links to other related topics are also made throughout and this is exemplified by the final task of the lesson where students are challenged on their recall of the structure, properties and function of starch (as originally covered in topic 1) As described above, this lesson has been specifically planned to prepare students for the upcoming lessons that cover the details of specification points 5.7 & 5.8 (i) and (ii).

This lesson describes how the products of the light-independent reactions of photosynthesis are used by plants, animals and other organisms. The engaging and detailed PowerPoint and accompanying resources have been primarily designed to cover point 5.8 (ii) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification concerning the uses of GP and GALP but as the lesson makes continual references to biological molecules, it can act as a revision tool for a lot of the content of topic 1 and 2. The previous lesson described the light-independent reactions and this lesson builds on that understanding to demonstrate how the intermediates of the cycle, GP and GALP, are used. The start of the lesson challenges the students to identify two errors in a diagram of the cycle so that they can recall that most of the GALP molecules are used in the regeneration of ribulose bisphosphate. A quiz version of Pointless runs throughout the lesson and this is used to challenge the students to recall a biological molecule from its description. Once each molecule has been revealed, time is taken to go through the details of the formation and synthesis of this molecule from GALP or from GP in the case of fatty and amino acids. The following molecules are considered in detail during this lesson: glucose (and fructose and galactose) sucrose starch and cellulose glycerol and fatty acids amino acids nucleic acids A range of activities are used to challenge their prior knowledge of these molecules and mark schemes are always displayed for the exam-style questions to allow the students to assess their understanding. As detailed above, this lesson has been specifically written to tie in with the earlier lessons in this topic on the structure of the chloroplast and the light-dependent and light-independent reactions of photosynthesis

This lesson describes the light-independent reactions of photosynthesis as reduction of carbon dioxide using the products of the light-dependent reactions. The detailed PowerPoint and accompanying resources have been designed to cover point 5.8 (i) of the Pearson Edexcel A-level Biology A (Salters-Nuffield) specification and therefore describes carbon fixation in the Calvin cycle and the roles of GP, GALP, RuBP and RUBISCO). The lesson begins with an existing knowledge check where the students are challenged to recall the names of structures, substances and reactions from the light-dependent stage in order to reveal the abbreviations of the main 3 substances in the light-independent stage. This immediately introduces RuBP, GP and GALP and students are then shown how these substances fit into the cycle. The main section of the lesson focuses on the three phases of the Calvin cycle and time is taken to explore the key details of each phase and includes: The role of RUBISCO in carbon fixation The role of the products of the light-dependent stage, ATP and reduced NADP, in the reduction of GP to GALP The use of the majority of the GALP in the regeneration of RuBP A step-by-step guide, with selected questions for the class to consider together, is used to show how 6 turns of the cycle are needed to form the GALP that will then be used to synthesise 1 molecule of glucose. A series of exam-style questions are included at appropriate points of the lesson and this will introduce limiting factors as well as testing their ability to answer questions about this stage when presented with an unfamiliar scientific investigation. The mark schemes are included in the PowerPoint so students can assess their understanding and any misconceptions are immediately addressed. This lesson has been specifically written to tie in with the previous lessons on the structure of a chloroplast and the light-dependent reactions as well as the upcoming lesson on the products of the light-independent reactions.

This lesson describes the light-dependent reactions of photosynthesis, focusing on the link to the light-independent reactions. The detailed PowerPoint and accompanying resources have been designed to cover the details included in point 5.7 of the Edexcel A-level Biology specification and therefore describes how light energy is trapped by exciting electrons in chlorophyll and the role of these electrons in generating ATP, reducing NADP in photophosphorylation and producing oxygen through photolysis of water. This is a topic which students tend to find difficult so this lesson has been intricately planned to walk them through each of the key reactions in the light-dependent stage. Time is taken to describe the roles of the major protein complexes that are embedded in the thylakoid membrane and this includes the two photosystems, the proton pump and ATP synthase. A series of exam-style questions have been written that link to other biological topics in this course such as cell structure and membrane transport as well as application questions to challenge them to apply their understanding. Some of these resources have been differentiated to allow students of differing abilities to access the work and to be pushed at the same time. Students will learn that there are two pathways that the electron can take from PSI and at the completion of the two tasks which describe each of these pathways, they will understand how ATP is generated in non-cyclic and cyclic fashion. The final task of the lesson asks them to compare these two forms of photophosphorylation to check that they understand when photolysis is involved and reduced NADP is formed. Due to the detail included in this lesson, it is estimated that it will take in excess of 2.5 hours of allocated A-level teaching time to complete