This concise lesson has been written to cover the detail of specification point 14.1 (d) of the CIE International A-level Biology specification which states that students should be able to describe the deamination of amino acids and outline the formation of urea in the urea cycle. Over the course of the lesson, students will discover that the amino group is removed during deamination to produce a keto acid and ammonia. They are encouraged to consider why the ammonia cannot accumulate in the body before looking at the different stages of the urea cycle. Instead of simply giving them the diagram of the urea cycle, students are given the opportunity to study the cycle when it is split into one of the three stages but are not allowed to draw. This task will challenge the students on their observational skills and then their ability to apply when they are given a question on the cycle. Included throughout the lesson are a selection of understanding checks and prior knowledge checks which allows the students to assess their progress against the current topic as well as challenging them to make links to previously covered topics. This lesson has been designed for students on the CIE International A-level Biology course and ties in well with the other uploaded lessons on topic 14.1 (Homeostasis in mammals)

This fully-resourced REVISION LESSON has been designed to provide the students with numerous opportunities to assess their understanding of the content of topic 12 (Energy and respiration) of the CIE International A-level Biology specification. The importance of this metabolic reaction is obvious and this is reflected in the volume of questions in the terminal exams which require an in depth knowledge of the stages of both aerobic and anaerobic respiration. The lesson contains a wide range of activities that cover the following points of the specification: Glycolysis as a stage of aerobic and anaerobic respiration The use and production of ATP through respiration Anaerobic respiration in mammalian muscle tissue The stages of aerobic respiration that occur in the mitochondrial matrix Oxidative phosphorylation The use of respirometers Calculating the respiratory quotient value for different substrates Revision lessons which cover the other topics of the specification are also uploaded and tie in well with this lesson.

This detailed and engaging REVISION LESSON has been written to cover the content of topic 4 (Cell membranes and transport) of the CIE International A-level Biology specification. The lesson consists of a PowerPoint that contains exam questions, differentiated tasks and quiz competitions and is accompanied by worksheets with further activities. The competitions act to engage the students whilst they assess their understanding of the content and challenges their ability to apply this knowledge to potentially unfamiliar situations. The lesson was designed to cover as much of the specification content as possible but the following sub-topics have received particular attention: Active transport and its applications in animals and plants Facilitated diffusion and the use of channel and carrier proteins The factors that affect diffusion as demonstrated by gas exchange at the alveoli Exocytosis Water potential and the movement of water by osmosis The effect of solutions of different water potentials on animal and plant tissue The fluid mosaic model The plasma cell membrane and the function of its components As well as covering the current topic, the design of this lesson has been conscious to include future topics. For example, a cholinergic synapse was used to challenge the students to spot examples of facilitated diffusion, simple diffusion, active transport and exocytosis. Revision lessons for the other 18 topics are uploaded on TES or are in the process of being uploaded.

This fully-resourced lesson challenges the students to use fully labelled genetic diagrams to interpret the results of monohybrid and dihybrid crosses as detailed in topic 7.1 (Inheritance) of the AQA A-level Biology specification. Step-by-step guides are used to demonstrate how diagrams for the inheritance of one and two genes should be constructed and a focus is given to the areas where students commonly make mistakes, such as in writing out the gametes. The main task of each section of the lesson provides an opportunity for the students to apply their understanding by calculating phenotypic ratios. All of the questions have fully-explained mark schemes and students can assess their progress and address any misconceptions immediately. Key genetic terminology is used throughout the lesson and mirrors that used in actual exam questions.

This concise and engaging lesson has been designed to cover specification point 15.1 (j) of the CIE International A-level Biology specification which states that students should be able to describe the ultrastructure of striated muscle with particular reference to sarcomere structure. The wide range of key terms and regions are introduced in a fun and memorable way using a variety of activities that include quiz competitions and then understanding checks are used throughout to assess their progress and ensure that any misconceptions are addressed. Connections are made to the upcoming topic of the sliding filament model as the students discover that despite the shortening of the sarcomere (and I band and H zone) during contraction, the fact that the A band remains the same length shows how the filaments slide over each other. The two main tasks of the lesson challenge the students to label a diagram of a sarcomere and then the microscope image as shown in the cover picture. This lesson has been designed to tie in well with the other uploaded lessons that cover the content of topic 15.1 of the CIE International A-level Biology course which is the control and coordination in mammals

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 explores sex-linkage and specifically the inheritance of sex-linked diseases in humans and then challenges the students to apply their knowledge to examples in other animals. The detailed PowerPoint and associated differentiated resources have been designed to cover the part of point 16.2 (b) of the CIE International A-level Biology specification which states that students should be able to use genetic diagrams to solve problems involving sex-linkage. Key genetic terminology is used throughout and the lesson begins with a check on their ability to identify the definition of homologous chromosomes. Students will recall that the sex chromosomes are not fully homologous and that the smaller Y chromosome lacks some of the genes that are found on the X. This leads into one of the numerous discussion points, where students are encouraged to consider whether females or males are more likely to suffer from sex-linked diseases. In terms of humans, the lesson focuses on haemophilia and red-green colour blindness and a step-by-step guide is used to demonstrate how these specific genetic diagrams should be constructed and how the phenotypes should then be interpreted. The final tasks of the lesson challenge the students to carry out a dihybrid cross that involves a sex-linked disease and an autosomal disease before applying their knowledge to a question about chickens and how the rate of feather production in chicks can be used to determine gender. All of the tasks are differentiated so that students of differing abilities can access the work and all exam questions have fully-explained, visual markschemes to allow them to assess their progress and address any misconception

This engaging lesson explains why coenzymes, cofactors and prosthetic groups are needed in some enzyme-controlled reactions. The PowerPoint and accompanying resource have been primarily designed to cover point 2.1.4 (e) of the OCR A-level Biology specification but can also be used as a revision lesson for the roles of ions as was covered back in module 2.1.2. The lesson begins with an introduction of the description of a cofactor and students will learn that some are permanently bound to the enzyme whilst others only form temporary associations. A quick quiz competition runs over the course of the lesson and is used to introduce prosthetic groups, mineral ion cofactors and organic coenzymes and zinc ions with carbonic anhydrase, chloride ions with amylase and NAD are used as examples of each type. The lesson has been planned to make links to related topics such as cations, anions, transport of carbon dioxide and respiration which will test students on their prior knowledge as well as prepare them for these topics in modules 3 and 5.

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-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 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 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 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 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.