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.

This lesson describes the role of abscisic acid in the closure of stomata during times of water stress, including the role of calcium ions. The PowerPoint and accompanying resources have been planned to cover the content of point (4) of topic 14.2 of the CIE A-level biology specification (for assessment in 2025-27). The lesson begins with an introduction of water stress and the description of the need for plants to adapt to these conditions because they can’t flee like animals can. A step-by-step guide underpins the lesson, consisting of 8 key steps in the mechanism. A series of tasks run alongside this, supporting the students with their understanding of key substances, such as abscisic acid, calcium ions, and potassium ions. There are multiple understanding checks, with answers embedded into the PowerPoint, to allow students to assess their own progress. There are also prior knowledge checks which encourage students to make links to previously covered content, including the response to a low blood glucose, and also the role of ions in living organisms. This lesson has been specifically designed to follow the lesson on guard cells and stomata, which is also uploaded.

This lesson explains why the conduction of an impulse along myelinated neurones is faster than along unmyelinated neurones. The PowerPoint and accompanying resources have been written to cover point (7) of topic 15.1 of the CIE A-level Biology specification. A wide range of activities are included in this lesson to maintain the motivation of the students whilst ensuring that the detail is covered in depth. Interspersed with the activities are understanding checks and prior knowledge checks to allow the students to not only assess their understanding of the current topic but also challenge themselves to make links to earlier topics such as the movement of ions across membranes and biological molecules. Over the course of the lesson, students consider the structure of the myelin sheath and specifically how the electrical insulation is not complete all the way along. This leaves gaps, known as the nodes of Ranvier, which allow the entry and exit of ions. Saltatory conduction can be poorly explained by a lot of students so time is taken to look at the way that the action potential jumps between the nodes and this is explained further by reference to local currents. The rest of the lesson focuses on the other two factors which are axon diameter and temperature and students are challenged to discover these two by focusing on the vampire squid.

This lesson describes the ultrastructure of striated muscle with particular reference to sarcomere structure. The PowerPoint and accompanying resource have been planned to cover point (11) of topic 15.1 of the CIE A-level Biology specification. There are a wide range of key terms and regions in this topic so they are introduced in a fun and memorable way using a variety of activities that include quiz competitions. These are followed by understanding checks to allow students 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 describes the structure of a cholinergic synapse and outlines the role of these connections in the nervous system. The fully-resourced lesson has been designed to cover the content of point (9) of topic 15.1 of the CIE A-level biology specification (for assessment in 2025-27). The majority of the lesson uses the cholinergic synapse as the example but other neurotransmitters are considered at the end of the lesson to provide the students with a wider view of this topic. One of the tasks near the beginning of the lesson challenges students to identify 3 terms from a WALL of key terms that could follow synaptic, having been introduced to the synaptic cleft on the previous slide. Not only will this challenge their prior knowledge from lessons earlier in topic 15 but it will also lead to the discovery of four of the structures that are found in a synapse. Moving forwards, students are introduced to acetylcholine as the neurotransmitter involved at cholinergic synapses and they will start to add labels to the structures found in the pre-synaptic bulb. Time is taken to focus on certain structures such as the voltage gated channels as these types of channel were met previously when looking at the depolarisation of a neurone. There is plenty of challenge and discovery as students are pushed to explain why organelles like mitochondria would be found in large numbers in the bulb. With this process being a cascade of events, a bullet point format is used to ensure that the key content is taken in by the students and again key points like exocytosis and the action of acetylcholinesterase are discussed further. The final part of the lesson challenges the application aspect of the subject as students are introduced to unfamiliar situations in terms of synapses with new drugs like MDMA and are asked to work out and explain how these affect the nervous transmission. Understanding checks and prior knowledge checks are included throughout the lesson so that students can not only assess their progress against the current topic but also see whether they can make links to earlier topics.

This lesson describes the features of the endocrine system, focusing on the differing actions of peptide and steroid hormones at target cells. The detailed PowerPoint and accompanying resources have been primarily designed to cover point (1) of topic 15.1 of the CIE A-level biology specification but can also be used as a revision tool to check on their knowledge of the role of glucagon in the homeostatic control of blood glucose concentration from topic 14 whilst introducing transcription factors which will be covered in topic 16. Students should have a base knowledge of the endocrine system from GCSE and topic 14 so this lesson has been planned to build on that knowledge and to add the detail needed at this level. The lesson begins by challenging this knowledge to check that they understand that endocrine glands secrete these hormones directly into the blood. Students will learn that most of the secreted hormones are peptide (or protein) hormones and a series of exam-style questions are used to challenge them on their recall of the structure of insulin as well as to apply their knowledge to questions about glucagon. Moving forwards, the students are reminded that hormones have target cells that have specific receptor sites on the surface of their membrane. The relationship between a peptide hormone as a first messenger and a second messenger on the inside of the cell is described to allow students to recall how the activation of cyclic AMP triggers a cascade of events on the inside of the cell. The rest of the lesson focuses on steroid hormones and specifically their ability to pass through the membrane of a cell and to bind to transcription factors, as exemplified by oestrogen.

This lesson describes the roles of the neuromuscular junction, including the sarcoplasmic reticulum and T-tubule system. The PowerPoint and accompanying resources have been planned to primarily cover the content of point (10) of topic 15.1 of the CIE A-level Biology specification, but also introduces striated muscle and the sliding filament model which are covered in the next two lessons. Due to a number of similarities between these structures and cholinergic synapses, this lesson uses prior knowledge of these connections between neurones to build a good understanding of the junctions. Students will discover that the events that occur at an axon tip mirror those which happen at the pre-synaptic bulb and this is then developed to look at the differences in terms of the events once the acetylcholine has bound to its receptor sites. There is a focus on the structure of the sarcolemma and time is taken to explain how the action potential is passed from this membrane to the transverse tubules in order to stimulate the release of calcium ions from the sarcoplasmic reticulum. As a result, this lesson ties in nicely with an upcoming lesson on the contraction of skeletal muscle and students will be able to link the binding to troponin in that lesson to the release of these ions from this lesson. Both of the main tasks of the lesson have been differentiated so that students of all abilities can access the work and make progress.