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 lesson describes how the sensory receptors of the nervous system detect stimuli by transducing different forms of energy into electrical energy. The PowerPoint has been designed to cover the content of the 1st part of specification point 8.5 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and acts as an introduction to the next lesson where the roles of the rod cells in the retina is described. The lesson begins by using a quiz to get the students to recognise the range of stimuli which can be detected by receptors. This leads into a task where the students have to form 4 sentences to detail the stimuli which are detected by certain receptors and the energy conversion that happen as a result. Students will be introduced to the idea of a transducer and learn that receptors always convert to electrical energy which is the generator potential. The remainder of the lesson focuses on the Pacinian corpuscle and how this responds to pressure on the skin, resulting in the opening of the sodium channels and the flow of sodium ions into the neurone to cause depolarisation.

This fully-resourced lesson describes the role of barriers in protecting the body from infection by pathogens when entering the body by the major routes. The engaging and detailed PowerPoint and accompanying resources have been designed to cover points 6.11 (i) & (ii) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and describe the following barriers: skin key steps of the blood clotting process mucous membranes stomach acid vaginal and skin flora There are clear links to topics 1, 2 and 3 in each of these barriers, so time is taken to consider these during the descriptions. For example, the presence of keratin in the cytoplasm of the skin cells allows the student knowledge of the properties of this fibrous protein to be checked. Other topics that are revisited during this lesson include blood clotting, protein structure, key terminology and the epithelium that lines the different parts of the airways. All of the exam-style questions and tasks have mark schemes that are embedded in the PowerPoint and a number of them have been differentiated to allow students of differing abilities to access the work.

This fully-resourced lesson describes the main stages of mitosis and explains the significance of this type of nuclear division in life cycles. The PowerPoint and accompanying resources have been designed to cover points 2.1.6 (c & e) of the OCR A-level Biology A specification and make direct links to the previous lesson which covered the cell cycle Depending upon the exam board taken at GCSE, the knowledge and understanding of mitosis will differ considerably between students and there may be a number of misconceptions. This was considered at all points during the planning of the lesson so that existing errors are addressed and key points are emphasised throughout. Their understanding of interphase is challenged at the start of the lesson to ensure that they realise that it is identical pairs of sister chromatids that enter the M phase. The main part of the lesson focuses on prophase, metaphase, anaphase and telophase and describes how the chromosomes behave in these stages. There is a focus on the centrioles and the spindle fibres that they produce which contract to drag one chromatid from each pair in opposite directions to the poles of the cell. The remainder of the lesson is a series of understanding and application questions where students have to identify the various roles of mitosis in living organisms as well as tackling a Maths in a Biology context question. The lesson concludes with a final quiz round of MITOSIS SNAP where they only shout out this word when a match is seen between the name of a phase, an event and a picture.

This 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 the function of transcription factors in eukaryotes and uses the lac operon to explain the control of protein production in a prokaryote. The detailed PowerPoint and accompanying resources have been designed to cover points 16.3 (b, c & d) as detailed in the CIE A-level Biology specification and also includes a description of how gibberellin breaks down DELLA protein repressors, allowing transcription to be promoted. This is one of the more difficult concepts in this A-level course and therefore key points are reiterated throughout this lesson to increase the likelihood of student understanding and to support them when trying to make links to actual biological examples in living organisms. There is a clear connection to transcription and translation as covered in topic 6, so the lesson begins by reminding students that in addition to the structural gene in a transcription unit, there is the promoter region where RNA polymerase binds. Students are introduced to the idea of transcription factors and will understand how these molecules can activate or repress transcription by enabling or preventing the binding of the enzyme. At this point, students are challenged on their current understanding with a series of questions about DELLA proteins so they can see how these molecules prevent the binding of RNA polymerase. Their understanding is then tested again with another example with oestrogen and the ER receptor. The final and main section of the lesson focuses on the lac operon and immediately an opportunity is taken to challenge their knowledge of biological molecules with a task where they have to spot the errors in a passage describing the formation and breakdown of this disaccharide. Students will be able to visualise the different structures that are found in this operon and time is taken to go through the individual functions. A step by step guide is used to walk students through the sequence of events that occur when lactose is absent and when it is present before they are challenged to apply their understanding to an exam question.

This lesson describes the behaviour of chromosomes during meiosis, focusing on the events which contribute to genetic variation. The detailed PowerPoint and accompanying resources have been designed to cover points 16.1 (a, d & e) of the CIE A-level Biology specification and explains how crossing over, the random assortment and the random fusion of haploid gametes leads to variation. In order to understand how the events of meiosis like crossing over and independent assortment and independent segregation can lead to variation, students need to be clear in their understanding that DNA replication in interphase results in homologous chromosomes as pairs of sister chromatids. Therefore the beginning of the lesson focuses on the chromosomes in the parent cell and this first part of the cycle and students will be introduced to non-sister chromatids and the fact that they may contain different alleles which is important for the exchange that occurs during crossing over. Time is taken to go through this event in prophase I in a step by step guide so that the students can recognise that the result can be new combinations of alleles that were not present in the parent cell. Moving forwards, the lesson explores how the independent assortment and segregation of chromosomes and chromatids during metaphase I and II and anaphase I and II respectively results in genetically different gametes. The key events of all of the 8 phases are described and there is a focus on key terminology to ensure that students are able to describe genetic structures in the correct context. The final part of the lesson looks at the use of a mathematical expression to calculate the possible combinations of alleles in gametes as well as in a zygote following the random fertilisation of haploid gametes. Understanding and prior knowledge checks are interspersed throughout the lesson as well as a series of exam-style questions which challenge the students to apply their knowledge to potentially unfamiliar situations. This lesson has been specifically planned to link to the two lessons on the cell cycle and the main stages of mitosis as covered in topic 5 and constant references are made throughout to encourage students to make links and also to highlight the differences between the two types of nuclear division

This lesson describes the biuret and emulsion tests for proteins and lipids respectively and then acts as a revision lesson for topics 2.2 and 2.3. The engaging PowerPoint and accompanying resources have been designed to be taught at the end of topic 2 and uses a range of activities to challenge the students on their knowledge of that topic, but also covers the second part of point 2.1 (a) of the CIE A-level Biology specification when the qualitative tests are described. The first section of the lesson describes the steps in the biuret test and challenges the students on their recall of the reducing sugars and starch tests from topic 2.1 to recognise that this is a qualitative test that begins with the sample being in solution. The students will learn that the addition of sodium hydroxide and then copper sulphate will result in a colour change from light blue to lilac if a protein is present. The next part of the lesson uses exam-style questions with displayed mark schemes, understanding checks and quick quiz competitions to engage and motivate the students whilst they assess their understanding of this topic. The following concepts are tested during this lesson: The general structure of an amino acid The formation of dipeptides and polypeptides through condensation reactions The primary, secondary, tertiary and quaternary structure of a protein Biological examples of proteins and their specific actions (e.g. antibodies, enzymes, peptide hormones) Moving forwards, the lesson describes the key steps in the emulsion test for lipids, and states the positive result for this test. There is a focus on the need to mix the sample with ethanol, which is a distinctive difference to the tests for reducing sugars and starch and proteins. The remainder of the lesson uses exam-style questions with mark schemes embedded in the PowerPoint, understanding checks, guided discussion points and quick quiz competitions to challenge the following specification points: The structure of a triglyceride The relationship between triglyceride property and function The hydrophilic and hydrophobic nature of the phospholipid The phospholipid bilayer of the cell membrane Cholesterol is also introduced so that the students are prepared for this molecule when it is met in topic 4 (cell membranes) This is an extensive lesson and it is estimated that it will take in excess of 2 hours of allocated teaching time to cover the detail and the different tasks

This lesson explains the effects of light intensity, carbon dioxide concentration and temperature (limiting factors) on the rate of photosynthesis. The PowerPoint and accompanying resources have been designed to cover points 13.2 (a, b & c) of the CIE A-level Biology specification and also considers how knowledge of these limiting factors can be used to increase crop yields in the protected environment of a greenhouse. The lesson has been specifically written to tie in with the previous lessons in topic 13.1 which covered the structure of the chloroplast, the light-dependent reactions and the light-independent reactions. Exam-style questions are included throughout the lesson and these require the students to explain why light intensity is important for both reactions as well as challenging them on their ability to describe how the relative concentrations of GP, TP and RuBP would change as carbon dioxide concentration decreases. There are also links to previous topics such as enzymes when they are asked to explain why an increase in temperature above the optimum will limit the rate of photosynthesis. Step by step guides are included to support them to form some of the answers and mark schemes are always displayed so that they can quickly assess their understanding and address any misconceptions. The final part of the lesson provides details of the World’s largest rooftop greenhouse in Montreal and challenges their knowledge of related topics such as cellulose structure, pollination and biological control.

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 describes the similarities and differences between the structure and function of haemoglobin and myoglobin. The PowerPoint and accompanying resource have been designed to cover point 4.5 (iii) of the Edexcel A-level Biology B specification Students have already covered the structure and function of haemoglobin in topics 1.3 and 4.5, so this concise lesson has been planned to challenge that knowledge. Students are introduced to myoglobin and will learn that this is an oxygen-binding protein found in the skeletal muscle tissue. Therefore the first part of the lesson focuses on slow twitch muscle fibres, where the content of myoglobin is high, and this presents an opportunity for links to be made to respiration, mitochondria and capillaries. The main part of the lesson challenges the students to compare the two proteins on structure and function including the number of polypeptide chains and affinity for oxygen and students can assess their understanding through use of the displayed mark schemes to the series of exam-style questions.

This lesson describes how tissue fluid is formed and reabsorbed and also describes the role of the lymphatic system in the return of fluid to the blood. The detailed PowerPoint and accompanying resources have been designed to cover points 4.6 (i & ii) of the Edexcel A-level Biology B specification and explains how a combination of the effects of hydrostatic pressure and oncotic pressure results in the formation of tissue fluid in animals. The lesson begins with an introduction to the arteriole and venule end of a capillary as these will need to be considered as separate entities when describing the formation of tissue fluid. A quick quiz competition introduces a value for the hydrostatic pressure at the arteriole end and students are challenged to first predict some parts of the blood will move out of the capillary as a result of the push from the hydrostatic pressure and this allows oncotic pressure to be initially explored. The main part of the lesson uses a step by step guide to describe how the net movement is outwards at the arteriole end before students will use this guidance to describe what happens at the venule end. In the concluding part of the lesson, students will come to recognise oedema as a condition where tissue fluid accumulates and they again are challenged to explain how this occurs before they finally learn how the fluid is returned to the circulatory system as lymph.

This lesson describes the transport mechanism of osmosis as the movement of water molecules from a high water potential to a lower water potential. The PowerPoint and accompanying resources are part of the second lesson in a series of 4 lessons which have been designed to cover point [c] as detailed in AS unit 1, topic 3 of the WJEC A-level Biology specification and also describes how cells are affected by this movement of water It’s likely that students will have used the term concentration in their osmosis definitions at GCSE, so the aim of the starter task is to introduce water potential to allow students to begin to recognise osmosis as the movement of water molecules from a high water potential to a lower potential, with the water potential gradient. Time is taken to describe the finer details of water potential to enable students to understand that 0 is the highest value (pure water) and that this becomes negative once solutes are dissolved. Exam-style questions are used throughout the lesson to check on current understanding as well as prior knowledge checks which make links to previously covered topics such as the lipid bilayer of the cell membrane. The remainder of the lesson focuses on the movement of water when animal and plant cells are suspended in hypotonic, hypertonic or isotonic solutions and the final appearance of these cells is described, including any issues this may cause.

This lesson describes the relationship between the specialised features of the mammalian egg and sperm and their functions. The PowerPoint and accompanying resources have been designed to cover point 3.11 of the Edexcel International A-level Biology specification and includes a focus on the acrosome in the head of the sperm and the zona pellucida in the egg The lessons at the start of topic 3 (Cell structure, Reproduction and Development) described the ultrastructure of eukaryotic cells, so this knowledge is referenced throughout the lesson and the students are challenged on their recall and understanding through a range of prior knowledge checks. For example, two of the exam-style questions that are included in the resources challenge the students to explain why a sperm cell is classified as an eukaryotic cell and to recognise the centrioles and the nucleus from structural descriptions. Along with the mitochondria, time is then taken to discuss and to describe the role of these organelles in relation to the function of the sperm cell. When considering the fusion of the haploid nuclei to form a diploid nucleus in the nucleus, links are made to the upcoming topic of mitosis and the significance of this form of nuclear division. The importance of the enzymes that are found inside the acrosome is emphasised and this leads into the second half of the lesson where the layers surrounding the plasma membrane of the egg cell (corona radiata and zona pellucida) are examined The final part of this lesson has been specifically planned to prepare the students for the next lesson in topic 3, where the acrosome reaction, cortical reaction and the fusion of nuclei that are involved in fertilisation are described