This is a highly detailed and engaging lesson that covers the detail of specification point 15.1 (e) of the CIE International A-level Biology specification which states that students should be able to describe and explain the transmission of an action potential in a myelinated neurone. This topic is commonly assessed in the terminal exams so a lot of time has been taken to design this resource to include a wide range of activities that motivate 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 has been designed for students studying the CIE International A-level Biology course and ties in nicely with other uploaded lessons which cover the content of topic 15.1 (Control and coordination in mammals)

This fully-resourced lesson describes how GALP is used as a raw material in the production of monosaccharides, amino acids and other molecules. The engaging and detailed PowerPoint and accompanying resources have been primarily designed to cover point 5.7 (vii) of the Edexcel A-level Biology B specification concerning the uses of 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. The previous lesson covered the light-independent stage and this lesson builds on that understanding to demonstrate how the product of the Calvin cycle, glyceraldehyde phosphate, is 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 module on the structure of the chloroplast and the light-dependent and light-independent stages of photosynthesis.

This fully-resourced lesson describes the relationship between the structure of monosaccharides and their roles in living organisms. The engaging PowerPoint and accompanying resources have been designed to cover the second part of points 1.2 & 1.4 of the Edexcel International A-level Biology specification and describes alpha-glucose, galactose, fructose, deoxyribose and ribose. The lesson begins by reminding students that monosaccharides are the simplest sugars and that these monomers provide energy. Using the molecular formula of glucose as a guide, students will be given the general formula for the monosaccharides and will learn that deoxyribose is an exception to the rule that the number of carbon and oxygen atoms are equal. Moving forwards, students have to study the displayed formula of glucose for two minutes without being able to note anything down before they are challenged to recreate what they saw in a test of their observational skills. At this point of the lesson, the idea of numbering the carbons is introduced so that the different glycosidic bonds can be understood in an upcoming lesson as well as the recognition of the different isomers of glucose. The difference between alpha and beta-glucose is provided but students do not need to consider the beta form until topic 4. The remainder of the lesson focuses on the roles of the monosaccharides and the final task involves a series of application questions where the students are challenged to suggest why ribose could be considered important for active transport and muscle contraction

This fully-resourced lesson explores how the structure of capillaries, arteries and veins relate to their functions. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 1.7 of the Edexcel International A-level Biology specification. This lesson has been written to build on any prior knowledge from iGCSE or earlier in this topic to enable students to fully understand each type of blood vessel has its particular features. Students will be able to make the connection between the narrow lumen and elastic tissue in the walls of arteries and the need to maintain the high pressure of the blood. A quick version of GUESS WHO is used to introduce smooth muscle and collagen as the substances that are found in the tunica media and externa and again the reason for their presence is explored and explained. The next part of the lesson looks at the role of the capillaries in exchange and links are made to diffusion to ensure that students can explain how the red blood cells pressing against the endothelium results in a short diffusion distance. The remainder of the lesson considers the structure of the veins and students are challenged to explain how the differences to those observed in arteries is due to the lower blood pressure found in these vessels. Valves are introduced and important mechanisms like the skeletal muscle pump are discussed to ensure that students can understand how the return of blood to the right atrium of the heart is maintained.

This fully-resourced lesson explains the meaning of biodiversity and describes how it can be calculated within a habitat and within a species. The engaging PowerPoint and accompanying resources have been designed to cover point 4.2 of the Pearson Edexcel A-level Biology A specification and in addition to biodiversity, the meaning of endemism is also explained. A quiz competition called BIOLOGICAL TERMINOLOGY SNAP runs over the course of the lesson and this will engage the students whilst challenging them to recognise key terms from their definitions. This quiz will introduce species, population, biodiversity, endemic, heterozygote and natural selection and each of these terms is put into context once introduced. Once biodiversity has been revealed, the students will learn that they are expected to be able to measure biodiversity within a habitat, within a species and within different habitats so that they can be compared. The rest of the lesson uses step by step guides, discussion points and selected tasks to demonstrate how to determine species richness, the heterozygosity index and an index of diversity. Students are challenged with a range of exam-style questions where they have to apply their knowledge and all mark schemes are displayed and clearly explained within the PowerPoint to allow students to assess their understanding and address any misconceptions if they arise.

This lesson describes the structure of the chloroplast, focusing on the sites of the light-dependent and light-independent stages of photosynthesis. This fully-resourced lesson, which consists of an engaging PowerPoint and accompanying resources, has been designed to cover points 13.1 (a) & (b) of the CIE A-level Biology specification and has been specifically designed to introduce students to the grana and stroma as the site of the light-dependent and light-independent stages respectively before they are covered in greater detail in the lessons that are taught later in topic 13.1. Students were introduced to eukaryotic cells and their organelles in topic 1 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, a range of activities are used to ensure that key details are understood such as 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 TP in the Calvin cycle. Links to other topics are 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 2.2

This fully-resourced lesson describes the three main stages of the Calvin cycle as fixation, reduction and regeneration. The detailed PowerPoint and accompanying resources have been designed to cover the content of point 13.1 (g) of the CIE A-level Biology specification and detailed planning ensures that continual links are made to the previous lesson on the light-dependent stage so that students understand how the products of that stage, ATP and reduced NADP, are essential for the Calvin cycle 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 Calvin cycle. This immediately introduces RuBP, GP and TP 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 TP The use of the majority of the TP in the regeneration of RuBP A step-by-step guide, with discussion points where the class are given time to discuss the answer to selected questions, is used to show how 6 turns of the cycle are needed to form the TP 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 describes the mode of actions of macrophages, neutrophils and lymphocytes. The engaging PowerPoint and accompanying resource have been primarily designed to cover point 6.7 (i) of the Edexcel A-level Biology B specification but includes an introduction to antigen-presentation so that the students are prepared for upcoming lessons on the cell-mediated and humoral responses. 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 lesson concludes with an introduction to lymphocytes so that initial links between phagocytosis and the specific immune responses are made.

This fully-resourced lesson describes how vaccinations are used to control disease and how immunity can be natural, artifical, active and passive. The engaging PowerPoint and accompanying resources have been designed to cover points 6.7 (v) & (vi) of the Edexcel A-level Biology B specification and there is also a description and discussion on the development of herd immunity. The previous lesson finished with a series of exam questions where students observed differences between the primary and secondary immune responses so the start of this lesson uses an imaginary game of TOP TRUMPS to challenge them on the depth of their understanding. This will act to remind them that a larger concentration of antibodies is produced in a quicker time in the secondary response. The importance of antibodies and the production of memory cells for the development of immunity is emphasised and this will be 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 structural and physiological differences between fast and slow twitch muscle fibres. The detailed PowerPoint and accompanying resources have been designed to cover point 7.10 (ii) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and due to the obvious links, this lesson also challenges the students on their knowledge of respiration from earlier in topic 7 and cell structures and biological molecules from topics 1, 2 and 3 The following structural and physiological characteristics are covered over the course of this lesson: Reliance on the aerobic or anaerobic pathways to generate ATP Resistance to fatigue mitochondrial density capillary density myoglobin content (and colour) fibre diameter phosphocreatine content glycogen content A wide variety of tasks are used to cover this content and include knowledge recall and application of knowledge exam-style questions with fully-displayed mark schemes as well as quick quiz competitions to maintain motivation and engagement. This lesson has been specifically planned to tie in with the previous lesson in this topic covering the contraction of skeletal muscles by the sliding filament mechanism

This lesson describes the overall reaction of aerobic respiration, introducing the 4 stages before the finer details are covered in the upcoming lessons. The engaging PowerPoint and accompanying resource have been designed to cover points 7.1 (i) and (ii) of the Edexcel International A-level Biology specification and explains how each step in this many-stepped process is catalysed by a specific intracellular enzyme. The lesson begins with an introduction to glycolysis and students will learn how this first stage of aerobic respiration is also the first stage when oxygen is not present. This stage involves 10 reactions and an opportunity is taken to explain how each of these reactions is catalysed by a different, specific intracellular enzyme. A version of “GUESS WHO” challenges students to use a series of structural clues to whittle the 6 organelles down to just the mitochondrion so that they can learn how the other three stages take place inside this organelle. Moving forwards, the key components of the organelle are identified on a diagram. Students are introduced to the stages of respiration so that they can make a link to the parts of the cell and the mitochondria where each stage occurs. Students will learn that the presence of decarboxylase and dehydrogenase enzymes in the matrix along with coenzymes and oxaloacetate allows the link reaction and the Krebs cycle to run and that these stages produce the waste product of carbon dioxide. Finally, time is taken to introduce the electron transport chain and the enzyme, ATP synthase, so that students can begin to understand how the flow of protons across the inner membrane results in the production of ATP and the the formation of water when oxygen acts as the final electron acceptor.

This detailed lesson describes the roles of the link reaction and the Krebs cycle in the complete oxidation of glucose which occur in the mitochondrial matrix. The PowerPoint and the accompanying resource have been designed to cover point 7.3 of the Edexcel International A-level Biology specification and includes descriptions of the formation of carbon dioxide, ATP, reduced NAD and FAD The lesson begins with a challenge, where the students have to recall the details of glycolysis in order to form the word matrix. This introduces the key point that these two stages occur in this part of the mitochondria and time is taken to explain why the reactions occur in the matrix as opposed to the cytoplasm like glycolysis. Moving forwards, the Link reaction is covered in 5 detailed bullet points and students have to add the key information to these points using their prior knowledge as well as knowledge provided in terms of NAD. The students will recognise that this reaction occurs twice per molecule of glucose and a quick quiz competition is used to test their understanding of the numbers of the different products of this stage. This is just one of the range of methods that are used to check understanding and all answers are explained to allow students to assess their progress. The rest of the lesson focuses on the Krebs cycle. In line with the detail of the specification, students will understand how decarboxylation and dehydrogenation reactions result in the regeneration of the oxaloacetate

This lesson describes how the electron transport chain and the chemiosmosis are involved in the synthesis of ATP by oxidative phosphorylation. The PowerPoint has been designed to cover point 7.4 of the Edexcel International A-level Biology specification and also looks at the role of the enzyme, ATP synthase. The lesson begins with a discussion about the starting point of the reaction. In the previous stages, the starting molecule was the final product of the last stage but in this stage, it is the reduced coenzymes which release their hydrogen atoms. Moving forwards, the process of oxidative phosphorylation is covered in 7 steps and at each point, key facts are discussed and explored in detail to enable a deep understanding to be developed. Students will see how the proton gradient is created and that the flow of protons down the channel associated with ATP synthase results in a conformational change and the addition of phosphate groups to ADP. Understanding checks are included throughout the lesson to enable the students to assess their progress. This lesson has been specifically written to tie in with the other uploaded lessons on glycolysis, the link reaction and Krebs cycle.

This fully-resourced lesson looks at the use of electrocardiograms to aid the diagnosis of abnormal heart rhythms. The engaging PowerPoint and accompanying resources have been designed to cover point 7.12 (iii) of the Edexcel International A-level Biology specification but also can be used as a revision lesson as the students are challenged on their prior knowledge of the cardiac cycle and heart structure as covered in topic 1. The lesson has been written to take place in an imaginary cardiology ward where the students are initially challenged on their knowledge of the symptoms and risk factors of CVD before looking at testing through the use of ECGs and diagnosis. The main focus of the lesson is the ECG and a quiz competition is used to introduce the reference points of P, QRS and T 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 has been designed to tie in with the lesson that covers the previous specification point on the normal electrical activity of the heart and the myogenic nature of cardiac muscle

This fully-resourced lesson describes the behaviour of chromosomes during the mitotic cell cycle and explains the importance of this type of nuclear division. The PowerPoint and accompanying resources have been designed to cover points 5.1 (b) & 5.2 (a) of the CIE A-level Biology specification and make direct links to a previous lesson which covered the outline of cell cycle Depending upon the exam board taken at iGCSE, 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 how the critical evaluation of new data by the scientific community leads to new taxonomic groupings, like the three domains of life. The detailed PowerPoint and accompanying resources have been designed to cover point 4.6 (ii) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and focuses on the introduction of the three-domain system following Carl Woese’s detailed study of the ribosomal RNA gene. The lesson begins with an introduction of Woese and goes on to describe how he is most famous for his definition of the Archaea as a new domain of life. Students were introduced to domains and the other classification taxa in a previous lesson, so their recall of this knowledge is continually tested and built upon as details are added. Students will discover the key differences between Archaea and Bacteria that led to the splitting of the prokaryotae kingdom and the addition of this higher classification rank. Moving forwards, the rest of the lesson describes how molecular phylogeny uses other molecules and that these are compared between species for classification purposes. One of these is a protein called cytochrome which is involved in respiration and can be compared in terms of primary structure to determine relationships. At this point in the lesson, the students are also tested on their knowledge of the nature of the genetic code (as covered in topic 2) and have to explain how mutations to DNA can also be used for comparative purposes.

This lesson explains that autosomal linkage results from the presence of alleles on the same chromosome and uses biological examples to demonstrate this concept. The PowerPoint and accompanying worksheets have been designed to cover point 8.2 (iv) of the Edexcel A-level Biology B specification and supports students in the formation of their descriptions of how these results of these crosses can be explained by the events of meiosis (crossing over) This is a difficult topic which can be poorly understood by students so extra time was taken during the planning to split the concept into small chunks. There is a clear focus on using the number of parent phenotypes and recombinants in the offspring as a way to determine linkage and suggest how the loci of the two genes compare. Important links to other topics such as crossing over in meiosis are made to enable students to understand how the random formation of the point of contact (chiasma) determines whether new phenotypes will be seen in the offspring or not. Linkage is an important cause of variation and the difference between observed and expected results and this is emphasised on a number of occasions and a link to the chi squared test which is covered in an upcoming lesson is also made. The main task of the lesson act as understanding check where students are challenged to analyse the results of genetic crosses involving the inheritance of the ABO blood group gene and the nail-patella syndrome gene n humans and also the inheritance of body colour and wing length in Drosophila.

This fully-resourced lesson describes the blood clotting process and includes the release of thromboplastin and the subsequent conversions to thrombin and fibrin. The engaging PowerPoint and accompanying worksheets have been primarily designed to cover the content detailed in point 1.6 of the Pearson Edexcel A-level Biology A specification but time has been taken to look at haemophilia as a sex-linked disease so that students are prepared for sex-linkage when covered in topic 3. The lesson begins with the introduction of clotting factors as integral parts of the blood clotting process and explains that factor III, thromboplastin, needs to recalled as well as the events that immediately precede and follows its release. Students will learn how damage to the lining and the exposure of collagen triggers the release of this factor and how a cascade of events then results. Quick quiz rounds and tasks are used to introduce the names of the other substances involved which are prothrombin, thrombin, fibrinogen and fibrin. In a link to the upcoming topic of proteins, students will understand how the insolubility of fibrin enables this mesh of fibres to trap platelets and red blood cells and to form the permanent clot. In the previous lessons, students described the events in atherosclerosis and a link is made to the role of blood clotting in CVD. The final part of the lesson introduces haemophilia as a sex-linked disease and students are challenged to apply their knowledge to an unfamiliar situation as they have to write genotypes and determine phenotypes before explaining why men are more likely to suffer from this disease than women.

This detailed lesson describes the key structural features of a prokaryotic cell and compares these against the structures of an eukaryotic cell. The engaging PowerPoint and accompanying resources have been designed to cover specification points 1.2 (d) & (e) as detailed in the CIE International A-level Biology specification and describes how the size and cell structures differ as well as the additional features that are found in some prokaryotic cells and briefly introduces binary fission. A clear understanding of terminology is important for A-level Biology so this lesson begins with a challenge, where the students have to recognise a prefix that they believe translates as before or in front of . This leads into the discovery of the meaning of prokaryote as before nucleus and this acts to remind students that these types of cell lack this cell structure. Links to the previous lessons on the eukaryotic cells are made throughout the lesson and at this particular point, the students are asked to work out why the DNA would be described as naked and to state where it will be found in the cell. Moving forwards, the students will discover that these cells also lack membrane bound organelles and a quick quiz competition challenges them to identify the specific structure that is absent from just a single word. In addition to the naked DNA, students will learn that there are also ribosomes in the cytoplasm and will discover that these are smaller than those found in the cytoplasm of an eukaryotic cell (but the same size as those in chloroplasts and mitochondria). The remainder of the lesson focuses on the composition of the cell wall, the additional features of prokaryotic cells such as plasmids and there is also the introduction of binary fission as the mechanism by which these organisms reproduce

This fully-resourced lesson describes how DNA is replicated semi-conservatively, including the roles of DNA helicase, polymerase and ligase. The detailed PowerPoint and accompanying resources have been designed to cover point 1.4 (ii) of the Edexcel A-level Biology B specification The main focus of this lesson is the roles of DNA helicase in the breaking of the hydrogen bonds between nucleotide bases, DNA polymerase in forming the growing nucleotide strands and DNA ligase in the joining of the nucleic acid fragments. Time is taken to explain key details, such as the assembly of strands in the 5’-to-3’ direction, so that the continuous manner in which the leading strand is synthesised can be compared against that of the lagging strand. The students are constantly challenged to make links to previous topics such as DNA structure and hydrolysis reactions through a range of exam questions and answers are displayed so that any misconceptions are quickly addressed. The main task of the lesson asks the students to use the information provided in the lesson to order the sequence of events in DNA replication before discussing how the presence of a conserved strand and a newly built strand in each new DNA molecule shows that it is semi-conservative.