This lesson describes how chloroplast pigments can be separated by chromatography and the pigments identified by Rf values. The PowerPoint and accompanying resource have been planned to cover point 5.7 of the Edexcel International A-level biology specification and to build and check on the knowledge acquired in the previous lesson on the absorption and action spectrum. The lesson begins with a challenge, where the students must recall that chromatography is the separation method that has a stationary and a mobile phase and then to realise that the chloroplast pigments could be separated using this technique. A step-by-step guide goes through the thin-layer chromatography process, and understanding and prior knowledge checks are used throughout to add key details. Moving forwards, the formula for the retention factor is provided, and the students are challenged to apply this formula to recognise the values for the chlorophylls and the carotenoids to allow them to be identified. All answers to the understanding and prior knowledge checks are embedded into the PowerPoint to allow students to assess their progress.

This lesson describes how thin-layer chromatography can be used to separate photosynthetic pigments. The PowerPoint and accompanying resource are part of the 2nd lesson in a series of 2 lessons which have been planned to cover point [c] of module 5.2.1 of the OCR A-level biology A specification. As mentioned above, this lesson has been designed to build and check on knowledge from the previous lesson which covered the importance of the photosynthetic pigments. The lesson begins by challenging them to recall that chromatography is the separation method that has a stationary and a mobile phase and then to realise that the photosynthetic pigments could be separated using this technique. A step-by-step guide goes through the TLC process, and understanding and prior knowledge checks are used throughout to add key details. Moving forwards, the formula for the retention factor is provided, and the students are challenged to apply this formula to recognise the values for the chlorophylls and the carotenoids. All answers to the understanding and prior knowledge checks are embedded into the PowerPoint to allow students to assess their progress.

This lesson describes how to use thin-layer chromatography to separate and identify chloroplast pigments. The PowerPoint and accompanying resource have been planned to cover point (6) of topic 13.1 of the CIE A-level biology specification and to build and check on the knowledge acquired in the previous two lessons on the structure of the chloroplast and photosynthesis and the chloroplast pigments. As shown in the cover image, the lesson begins by challenging them to recall that chromatography is the separation method that has a stationary and a mobile phase and then to realise that the chloroplast pigments could be separated using this technique. A step-by-step guide goes through the TLC process, and understanding and prior knowledge checks are used throughout to add key details. Moving forwards, the formula for the retention factor is provided, and the students are challenged to apply this formula to recognise the values for the chlorophylls and the carotenoids to allow them to be identified. All answers to the understanding and prior knowledge checks are embedded into the PowerPoint to allow students to assess their progress.

This lesson describes the relationship between the structure of the chloroplast and the functions related to photosynthesis . This fully-resourced lesson, which consists of an engaging PowerPoint and accompanying resources, has been designed to cover points (1, 2 and 3) of topic 13.1 of the CIE A-level Biology specification. The lesson introduces 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 lesson describes the light-dependent stage, focusing on the production of ATP by photophosphorylation and reduced NADP. The detailed PowerPoint and accompanying resources have been designed to cover the details of points 7, 8, 9 and 10 of topic 13.1 of the CIE A-level Biology specification. The light-dependent stage of photosynthesis 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 up to 3 hours of allocated A-level teaching time to complete.

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 (1 & 2) of the CIE A-level Biology specification (for assessment in 2025-2027) 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 fully-resourced lesson describes the conversion of Calvin cycle intermediates to carbohydrates, lipids and amino acids. The engaging and detailed PowerPoint and accompanying resources have been primarily designed to cover point (12) of topic 13.1 of the CIE A-level Biology specification (for assessment in 2025 - 2027) concerning the uses of GP and TP 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 2. The previous lesson described the three stages of the Calvin cycle and this lesson builds on that understanding to demonstrate how the intermediates of the cycle, GP and TP, 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 TP 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 TP 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, the light-dependent stage of photosynthesis and the Calvin cycle.

This lesson describes the importance of homeostasis in mammals and focuses on the parts of a control system and negative feedback . The detailed and engaging PowerPoint and accompanying resources have been designed to cover the content of points (1 and 2) of topic 14.1 of the CIE A-level biology specification, but positive feedback is also discussed to broaden student understanding. As homeostasis is a topic met at GCSE, this lesson has been written to build on this knowledge as well as to check on their prior knowledge of earlier A-level topics such as osmosis when considering blood water potential and the use of glucose as a respiratory substrate. Discussion points are written into the lesson at regular intervals to encourage the students to consider why a particular process or method takes place and understanding checks allow them to assess their progress. Students will recall how body temperature, blood water potential and blood glucose concentration are maintained within restricted limits and the importance of these systems are looked into in detail. Time is taken to consider the importance of maintaining these aspects, specifically with relation to the activity of enzymes. As such, students will also discuss how the pH of the blood is maintained. The key components of the control system are recalled and then time is taken to focus on the cell signalling that occurs between the coordination centre and the effectors. Students will learn to associate the response with either the use of the nervous or endocrine system. The final part of the lesson looks at the importance of negative feedback in reversing the change in order to bring the aspect back to the optimum and the added degree of control which this provides. Positive feedback is also briefly mentioned at the end.

This lesson describes the mechanism by which the guard cells open and close the stomatal apertures in response to changes in environmental conditions. The PowerPoint and accompanying resources have been designed to cover points 1, 2 and 3 as set out in topic 14.2 of the CIE A-level biology specification (for assessment in 2025 - 2027). The lesson begins with a plant biology check, where the students have to spot the structure which isn’t found in a leaf, and then to spot the three leaf cells. This reveals the palisade and spongy mesophyll cells, but most importantly the guard cells. In a change to the normal, this lesson considers the function of the guard cells first before the structure is considered, and an understanding of the relationship between the two is embedded. Students will understand that there’s a balance between the opening of the stomatal aperture to allow carbon dioxide to diffuse in for photosynthesis, with the closing to reduce transpiration losses. The students’ knowledge of photosynthesis and other related topics are challenged throughout, and answers to all of the questions are found in the PowerPoint to allow the students to assess their progress. The final part of the lesson describes the mechanism by which the guard cells open the stomata, including details of ATP, potassium ions and the movement of water by osmosis.

This lesson describes the structure of the human kidney, focusing on gross structures like the renal artery and vein, before considering the nephron. The detailed PowerPoint and accompanying resource have been planned to cover the content of points (4 & 5) of topic 14.1 of the CIE A-level Biology specification (for assessment in 2025 - 27). The lesson was designed at the same time as the other lessons in this topic on ultrafiltration, selective reabsorption and osmoregulation so that a common theme runs throughout and students can build their knowledge up gradually to develop a deep understanding of this organ. Students will come to recognise the renal cortex and renal medulla as the two regions of the kidney and learn the parts of the nephron which are found in each of these regions. Time is taken to look at the vascular supply of this organ and specifically to explain how the renal artery divides into the afferent arterioles which carry blood towards the glomerulus and the efferent arterioles which carry the blood away. The main task of the lesson challenges the students to relate structure to function. Having been introduced to the names of each of the parts of the nephron, they have to use the details of the structures found at these parts to match the function. For example, they have to make the connection between the microvilli in the PCT as a sign that this part is involved in selective reabsorption.

This lesson describes the homeostatic control of blood glucose concentration using negative feedback mechanisms. The PowerPoint and accompanying resources have been planned to cover the content of points (9 and 10) of topic 14.1 of the CIE A-level Biology specification (for assessment in 2025-27) and therefore also explain how the binding of glucagon and the formation of a second messenger is cell signalling. The wide range of activities will maintain motivation and engagement whilst the content is covered in detail to enable the students to explain how the receptors in the pancreas detect the concentration change and how the hormones attaching to receptor sites on the liver triggers a series of events in this effector organ. This is a topic which has a huge amount of difficult terminology so time is taken to look at all of the key words, especially those which begin with the letter G so students are able to use them accurately in the correct context. The final part of the lesson looks at the role of the secondary messenger, cyclic AMP, and describes how this is involved when glucagon and adrenaline attach to receptors on the liver. The action of adrenaline is also considered and linked to the breakdown of glycogen to glucose during glycogenolysis.

This lesson describes how urea is produced in the liver from the deamination of excess amino acids. The engaging PowerPoint and accompanying resource have been designed to cover the content of point (3) of topic 14.1 of the CIE A-level biology specification (for assessment in 2025 - 27) The lesson begins by reminding students that excretion is one of the 7 characteristics of living organisms, as introduced within MRS GREN when they were younger. An A-level worthy definition of excretion is then introduced, and time is taken to ensure that students recognise that substances must be products of metabolism to be deemed to be excreted. Moving forwards, the role of the liver and then the kidneys in the excretion of urea are described. There is a focus on terminology, specifically prefixes and suffixes, to allow students to understand the meaning of deamination which occurs in the liver. The students will learn that ammonia and a keto acid are formed, and the former needs to be immediately converted to urea because of its solubility and toxicity. The final part of the lesson introduces the kidney as the destination for the urea after the liver and explains how this small molecule will be filtered and form the main component of urine.

This lesson describes the roles of the hypothalamus, posterior pituitary, ADH and collecting ducts in osmoregulation. The PowerPoint and accompanying resources have been planned to cover the content of point (8) of topic 14.1 of CIE A-level biology specification (for assessment in 2025-27). Students covered the principles of homeostasis and negative feedback in the first lesson in this topic, 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 explains how the structure of the Bowman’s capsule leads to the formation of glomerular filtrate by ultrafiltration. The PowerPoint and accompanying resource are part of the 1st lesson in a series of two lessons which have been planned to cover the content of points (6 and 7) of topic 14.1 of the CIE A-level Biology specification (for assessment in 2025-27) The lesson provides students with the opportunity to gauge a deep understanding of ultrafiltration and 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 The 2nd lesson in this series covers selective reabsorption.

This lesson describes the structure and function of sensory and motor neurones as well as the role of intermediate neurones. The PowerPoint and accompanying resources have been planned to cover the content of point (3) of topic 15.1 of the CIE A-level Biology specification (for assessment in 2025 - 27) and also focuses on the organisation of the nervous system to support students with their understanding of upcoming content in this topic. The PowerPoint has been designed to contain a wide range of activities that are interspersed between understanding and prior knowledge checks that allow the students to assess their progress on the current topics as well as challenge their ability to make links to topics from earlier in the modules. Quiz competitions like SAY WHAT YOU SEE are used to introduce key terms in a fun and memorable way. The students will be able to compare these neurones based on their function but also distinguish between them based on their structural features. Time is taken to introduce the importance of the myelin sheath that is present in both neurones to allow saltatory conduction to occur.