This lesson has been written to cover the part of specification point 5.1.2 © of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply an understanding of the process of selective reabsorption. It has specifically been designed to build on the knowledge gained in the previous lessons on the structure of the nephron and ultrafiltration. The lesson begins by challenging the students to recall the substances that are found in the glomerular filtrate so that each of them can be considered over the course of the rest of the lesson. Moving forwards, the first of the numerous discussion points which are included in the lesson is used to get students to predict the component of the filtrate which won’t be found in the urine when they are presented with pie charts from each of these situations. Upon learning that glucose is 100% reabsorbed, along with most of the ions and some of the water, the rest of the lesson focuses on describing the relationship between the structure of the PCT and the function of selective reabsorption. Again, this section begins by encouraging the students to discuss and to predict which structures they would expect to find in a section of the kidney if the function is to reabsorb. They are given the chance to see the structure (as shown in the cover image) before each feature is broken down to explain its importance. Time is taken to look at the role of the cotransporter proteins to explain how this allows glucose, along with sodium ions, to be reabsorbed from the lumen of the PCT into the epithelial cells. The final part of the lesson focuses on urea and how the concentration of this substance increases along the tubule as a result of the reabsorption of some of the water. This lesson has been designed for students studying on the OCR-A level Biology A course and ties in nicely with the other lessons from 5.1.2 (c and d) on the structure and function of the kidney

This is a highly-detailed and fully-resourced lesson which covers the detail of specification point 5.1.2 (d) of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply an understanding of the roles of the hypothalamus, posterior pituitary, ADH and the collecting duct in the control of the water potential of the blood. Students learnt about the principles of homeostasis and negative feedback in an earlier module, so this lesson acts to build on that knowledge and challenges them to apply their knowledge. A wide range of activities have been included in the lesson to maintain motivation and engagement whilst the understanding and prior knowledge checks will allow the students to assess their progress as well as challenge themselves to make links to other Biology topics. The lesson begins with a discussion about how the percentage of water in urine can and will change depending on the blood water potential. Students will quickly be introduced to osmoregulation and they will learn that the osmoreceptors and the osmoregulatory centre are found in the hypothalamus. A considerable amount of time is taken to study the cell signalling between the hypothalamus and the posterior pituitary gland by looking at the specialised neurones (neurosecretory cells). Links are made to the topics of neurones, nerve impulses and synapses and the students are challenged to recall the cell body, axon and vesicles. The main section of the lesson forms a detailed description of the body’s detection and response to a low blood water potential. The students are guided through this section as they are given 2 or 3 options for each stage and they have to use their knowledge to select the correct statement. The final task asks the students to write a detailed description for the opposite stimulus and this task is differentiated so those who need extra assistance can still access the work. This lesson has been written for students studying on the OCR A-level Biology A course and ties in nicely with the other uploaded lessons in module 5.1.2 which include the structure of the nephron, ultrafiltration and selective reabsorption.

This detailed lesson has been written to cover the part of specification point 5.1.2 © of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply an understanding of the process of ultrafiltration. The aim of the design was to give the students the opportunity to discover this particular function and to be able to explain how the mechanisms found in the glomerulus and the Bowman’s capsule control the movement of small molecules out of the blood plasma. Key terminology is used throughout and students will learn how the combination of the capillary endothelium and the podocytes creates filtration slits that allow glucose, water, urea and ions through into the Bowman’s capsule but ensure that blood cells and plasma proteins remain in the bloodstream. A number of quiz competitions are used to introduce key terms and values in a fun and memorable way whilst understanding and prior knowledge checks allow the students to assess their understanding of the current topic and to challenge themselves to make links to earlier topics. The final task of the lesson challenges the students to apply their knowledge by recognising substances found in a urine sample that shouldn’t be present and to explain why this would cause a problem This lesson has been written for students studying on the OCR A-level Biology A course and ties in nicely with the other 5.1.2 kidney lessons on the structure of the nephron, selective reabsorption, osmoregulation and kidney failure

This engaging lesson covers the detail of the 2nd part of specification point 5.1.3 (d) of the OCR A-level Biology specification which states that students should demonstrate and apply an understanding of the importance of synapses in summation and control, including inhibitory and excitatory synapses. This is a topic which is generally poorly understood by students or brushed over so considerable time has been taken to design the activities to motivate the students so that the content is memorable whilst still being covered in detail. Links are continually made to earlier topics in this module such as synapses and generator potentials but also to topics covered in the previous year and still to be covered. The lesson begins by challenging the students to recognise a description of generator potential and they will then discover that this is also known as an EPSP. Students will recall that a small depolarisation may not lead to the opening of the voltage gated channels and therefore the full depolarisation which is needed for the initiation of an action potential and will discuss how this problem could be overcome. Lots of discussion points like this are included in the lesson to encourage the students to challenge and debate why a particular process of mechanism occurs. Students will therefore learn that EPSPs can be combined and this is known as summation. A quiz round is used to introduce temporal and spatial summation. Moving forwards, students are presented with a number of examples where they have to decide why type of summation is involved. Again, the lesson has been written to include real-life examples such as chronic pain conditions so the chances of the content sticking is increased. The final part of the lesson introduces IPSPs and the effect of these on summation and action potentials is discussed. This lesson has been designed for students studying on the OCR A-level Biology course and ties in well with the other uploaded lessons from module 5.1.3 on sensory receptors, neurones, nerve impulses and cholinergic synapses

This lesson describes how to obtain and use sampling results to calculate an estimate for the population size of a sessile, slow-moving or motile organism. The PowerPoint and accompanying worksheets are part of the second lesson in a series of 4 lessons that have been designed to cover the content of topic 7.4 (Populations in ecosystems) of the AQA A-level Biology specification and includes descriptions of the use of randomly placed quadrats, quadrats along a belt transect and the mark-release-recapture method. As you can see from the image, step by step guides are included in the lesson that walk the students through each stage of the calculations and these are followed by opportunities to challenge their understanding by answering exam-style questions. Mark schemes for the 7 questions that are answered over the course of the lesson are embedded into the PowerPoint and this allows the students to assess their progress. When considering the mark-release-recapture method, the assumptions that are made and the precautions that need to be taken are considered and the students are challenged to link the changes in the numbers of rabbits to the topic of stabilising selection.

This fully-resourced lesson looks at the process and site of the Krebs cycle and explains the importance of decarboxylation, dehydrogenation, the reduction of NAD and FAD and substrate level phosphorylation. The engaging and detailed PowerPoint and accompanying resource have both been designed to cover point 5.2.2 (e) of the OCR A-level Biology A specification and includes the formation of citrate from the acetyl group of acetyl CoA and oxaloacetate and the regeneration of this four carbon molecule. The lesson begins with a version of the Impossible game where students have to spot the connection between 8 of the 9 terms and will ultimately learn that this next stage is called the Krebs cycle. The main part of the lesson challenges the students to use descriptions of the main steps of the cycle to continue their diagram of the oxidation-reduction reactions. Students are continually exposed to key terminology such as decarboxylation and dehydrogenation and they will learn where carbon dioxide is lost and reduced NAD and FAD are generated. They will also recognise that ATP is synthesised by substrate level phosphorylation. The final task challenges them to apply their knowledge of the cycle to work out the numbers of the different products and to calculate the number of ATP that must be produced in the next stage if the theoretical yield of 32ATP is to be achieved. This lesson has been designed to tie in with the other uploaded lessons on glycolysis, anaerobic respiration, the Link reaction, oxidative phosphorylation and respiratory substrates

This fully-resourced lesson describes how the functional differences of the retinal rod and cone cells is related to their structures. The detailed PowerPoint and accompanying resources are part of the 2nd in a series of 2 lessons that have been designed to cover the details included in point 6.1.2 of the AQA A-level Biology specification. However, as explained at the start of the lesson, it has been specifically planned to be taught after the lessons in topic 6.3, so that students are aware and understand the meaning of terms such as depolarisation and hyperpolarisation. It is likely that students will be aware that the human retina contains rod and cone cells, so this lesson builds on that knowledge and adds the detail needed at this level. Over the course of the lesson, students will learn that these cells contain different optical pigments and that this feature along with their differing connectivity to the bipolar neurones means that they have different sensitivities to light, colour perception and visual acuity. Exam-style questions are interspersed throughout to check on current understanding and also make links to previously covered topics. For example, students are challenged to recognise a description of the mitochondria so they can discover that this cell structure is found in the inner segment where it is responsible for generating the ATP needed to pump sodium ions out of the cells. As detailed above, this lesson ties in closely with topic 6.3 and students will be expected to make links to synapses and to the changes in membrane potential that occur when sodium ions move in or out of a cell

This lesson describes how to use the magnification formula to calculate the magnification or the actual size in a range of units. The PowerPoint and accompanying resources have been designed to cover the 3rd part of point 2.1.3 of the AQA A-level Biology specification The students are likely to have met the magnification formula at GCSE so this lesson has been written to build on that knowledge and to support them with more difficult questions when they have to calculate actual size without directly being given the magnification. A step by step guide is used to walk the students through the methodology and useful tips are provided. Students could be asked to calculate the actual size in millimetres, micrometres, nanometres or picometres so time is taken to ensure that they can convert between one and another. This lesson has been written to tie in with the previous two lessons on microscopes and measuring the size of an object and the two rounds of the ongoing quiz competition take place in this lesson.

This fully-resourced lesson describes the components of the chloroplast, focusing on the grana and stroma as the sites of photosynthesis. The engaging PowerPoint and accompanying resources have been designed to cover point 5.2.1 (b) of the OCR A-level Biology A specification and has been specifically designed to introduce students to the light-dependent and light-independent stages before they are covered in detail in upcoming lessons. Students were introduced to eukaryotic cells and their organelles structures in module 2.1.1 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 module 2.1.2)

This fully-resourced lesson describes the structure and general properties of slow and fast skeletal muscle fibres. The detailed PowerPoint and accompanying resources are the second in a series of 2 lessons that cover the content detailed in point 6.3 of the AQA A-level Biology specification and due to the obvious links, this lesson also challenges the students on their knowledge of respiration, cell structures and biological molecules like glycogen and haemoglobin The following structure and properties 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 topic 6.3, titled “Contraction of skeletal muscles”, and this lesson has been uploaded for free

This lesson describes the light-dependent stage of photosynthesis and focuses on the mechanisms involved in the production of ATP and reduced NADP. The detailed PowerPoint and accompanying resources have been designed to cover the details of point 5.2.1 (d) of the OCR A-level Biology A specification and has been specifically planned to link with the previous lesson on the structure of the chloroplast and photosynthesis and to prepare the students for the next lesson on the light-independent stage. The light-dependent stage is a process which students can find difficult to understand in the necessary detail so this lesson has been planned to walk them through all of the key details. 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 cytochrome 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 eukaryotic cell structures 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 photophosphorylation. 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 clear and detailed lesson describes the process of oxidative phosphorylation, including the roles of the electron carriers, oxygen and the mitochondrial cristae and explains the role of chemiosmosis. The PowerPoint has been designed to cover points 5.2.2 (g) and (h) of the OCR A-level Biology A specification and includes details of the electron transport chain, proton gradients and 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 detailed steps and at each point, key facts are discussed and explored in further detail to enable a deep understanding to be developed. Students will see how the proton gradient across the inner membrane 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 by oxidative phosphorylation. Understanding checks are included throughout the lesson to enable the students to assess their progress and prior knowledge checks allow them to recognise the clear links to other topics and modules. This lesson has been written to tie in with the other uploaded lessons on glycolysis, the Link reaction and Krebs cycle and anaerobic respiration

This fully-resourced lesson describes the series of reactions in the light- independent stage of photosynthesis. The detailed PowerPoint and accompanying resources have been designed to cover the details of point 5.2.1 (e) of the OCR A-level Biology A specification and detailed planning includes continual links to the previous lesson on the light-dependent stage to ensure that students recognise 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 light-independent stage. 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 consider 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 fully-resourced lesson uses real-life examples in plants and animals to explain why cellular respiration is so important. The PowerPoint and accompanying resources have been designed to cover point 5.2.2 (a) of the OCR A-level Biology A specification but can also be used as a revision tool to challenge the students on their knowledge of active transport, nervous transmission and muscle contraction. As the first lesson in this module, it has been specifically planned to act as an introduction to this cellular reaction and provides important details about glycolysis, the Krebs cycle and oxidative phosphorylation that will support the students to make significant progress when these stages are covered during individual lessons. Students met phosphorylation in module 5.2.1 when considering the light-dependent reactions of photosynthesis and their knowledge of the production of ATP in this plant cell reaction is called on a lot in this lesson to show the similarities. The students are also tested on their recall of the structure and function of ATP, as covered in module 2.1.3, through a spot the errors task. By the end of the lesson, the students will be able to explain why the ATP produced in cellular respiration is needed by root hair cells, by companion cells and in the selective reabsorption of glucose in the proximal convoluted tubule. They will also be able to name and describe the different types of phosphorylation and will know that ATP is produced by substrate-level phosphorylation in glycolysis and the Krebs cycle and by oxidative phosphorylation in the final stage of aerobic respiration with the same name.

This lesson describes the tests that detect reducing and non-reducing sugars and starch using Benedict’s solution and iodine/potassium iodide. The PowerPoint and accompanying resource are part of the last lesson in a series of 4 lessons which have been designed to cover the content of topic 1.2 (Carbohydrates) of the AQA A-level Biology specification. The lesson begins with an explanation of the difference between a qualitative and quantitative test so that the students recognise that the two tests described within this lesson indicate the presence of a substance but not how much. The students are likely to have met these tests at GCSE so this lesson has been planned to build on that knowledge and to add the knowledge needed at this level. A step by step guide walks the students through each stage of the tests for reducing and non-reducing sugars and application of knowledge questions and prior knowledge checks are included at appropriate points to ensure understanding is complete. Time is also taken to ensure that students understand the Science behind the results. The rest of the lesson focuses on the iodine test for starch and the students will learn that the colour change is the result of the movement of an ion into the amylose helix.

This lesson describes the relationship between the size of an organism or structure and its surface to volume ratio. The PowerPoint and accompanying worksheets have been designed to cover point 3.1 of the AQA A-level Biology specification and also have been specifically planned to prepare the students for the upcoming lessons in topic 3 on gas exchange and absorption in the ileum. The students are likely to have been introduced to the ratio at GCSE, but understanding of its relevance tends to be mixed. Therefore, real life examples are included throughout the lesson that emphasise the importance of the surface area to volume ratio in order to increase this relevance. A lot of students worry about the maths calculations that are associated with this topic so a step by step guide is included at the start of the lesson that walks them through the calculation of the surface area, the volume and then the ratio. Through worked examples and understanding checks, SA/V ratios are calculated for cubes of increasing side length and living organisms of different size. These comparative values will enable the students to conclude that the larger the organism or structure, the lower the surface area to volume ratio. A differentiated task is then used to challenge the students to explain the relationship between the ratio and the metabolic demands of an organism and this leads into the next part of the lesson, where the adaptations of larger organisms to increase the ratio at their exchange surfaces is covered. The students will calculate the SA/V ratio of a human alveolus (using the surface area and volume formulae for a sphere) and will see the significant increase that results from the folding of the membranes. This is further demonstrated by the villi and the microvilli on the enterocytes that form the epithelial lining of these folds in the ileum. The final part of the lesson introduces Fick’s law of diffusion so that students are reminded that the steepness of a concentration gradient and the thickness of a membrane also affect the rate of diffusion.

This fully-resourced lesson describes how natural selection results in species with anatomical, behavioural and physiological adaptations. The engaging and detailed PowerPoint and accompanying resources have been designed to cover the fourth part of point 4.4 of the AQA A-level Biology specification and make continual links to the earlier parts of this topic including evolution and genetics. A quick quiz competition at the start of the lesson introduces the different types of adaptation and a series of tasks are used to ensure that the students can distinguish between anatomical, behavioural and physiological adaptations. The Marram grass is used to test their understanding further, before a step by step guide describes how the lignified cells prevent a loss of turgidity. Moving forwards, the students are challenged to explain how the other adaptations of this grass help it to survive in its environment. A series of exam-style questions on the Mangrove family will challenge them to make links to other topics such as osmosis and the mark schemes are displayed to allow them to assess their understanding. The final part of the lesson focuses on the adaptations of the anteater but this time links are made to the upcoming topic of taxonomy so that students are prepared for this lesson on species and classification hierarchy.

Monosaccharides are the monomers from which larger carbohydrates are formed and this lesson describes their structure and roles in living organisms. The detailed and engaging PowerPoint and accompanying resources have been designed to cover the first part of point 1.2 of the AQA A-level Biology specification and looks at alpha-glucose, beta-glucose, galactose, fructose, deoxyribose and ribose. The lesson begins with a made-up round of the quiz show POINTLESS, where students have to try to identify four answers to do with carbohydrates. In doing so, they will learn or recall that these molecules are made from carbon, hydrogen and oxygen, that they are a source of energy which can sometimes be rightly or wrongly associated with obesity and that the names of the three main groups is derived from the Greek word sakkharon. 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 and students are again challenged to draw a molecule of glucose, this time for the beta form. The remainder of the lesson focuses on the roles of the 6 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 detailed and engaging lesson describes the structural similarities and differences between DNA and RNA. The PowerPoint and accompanying worksheet containing exam-style questions have been designed to cover point 1.5.1 of the AQA A-level Biology specification. In the first lesson of topic 1, the students were introduced to a number of monomers which included a nucleotide. In line with this, the start of the lesson challenges them to recognise the key term nucleotide when only the letters U, C and T are shown. The next part of the lesson describes the structure of a DNA nucleotide and an RNA nucleotide so that the pentose sugar and the bases adenine, cytosine and guanine can be recognised as similarities whilst deoxyribose and ribose and thymine and uracil are seen as the differences. Time is taken to discuss how a phosphodiester bond is formed between adjacent nucleotides and their prior knowledge and understanding of condensation reactions is tested through a series of questions. Students are then introduced to the purine and pyrimidine bases and this leads into the description of the double-helical structure of DNA and the hydrogen bonds between complementary bases. The final section of the lesson describes the structure of mRNA, tRNA and rRNA and students are challenged to explain why this single stranded polynucleotide is shorter than DNA In addition to the current understanding and prior knowledge checks, a number of quiz rounds have been written into the lesson to introduce key terms in a fun and memorable way and the final round acts as a final check on the structures of DNA and RNA.

This fully-resourced lesson describes the process of DNA replication and explains how this ensures genetic continuity between generations. Both the detailed PowerPoint and accompanying resources have been designed to cover point 1.5.2 of the AQA A-level Biology specification and also explains why it is known as semi-conservative. The main focus of this lesson is the roles of DNA helicase in the breaking the hydrogen bonds between nucleotide bases and DNA polymerase in forming the growing nucleotide strands. Students are also introduced to DNA ligase to enable them to understand how this enzyme functions to join 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.