This fully-resourced lesson describes the the overall reaction of photosynthesis that takes place in the grana and stroma of the chloroplast. The detailed PowerPoint and accompanying resources have been designed to cover points 5.1 & 5.5 in unit 4 of the Edexcel International A-level Biology specification and also describes the relationship between the structure and role of the chloroplast Students will have some knowledge of photosynthesis from iGCSE and were introduced to the ultrastructure of eukaryotic cells in topics 3 and 4 so this lesson has been written to test and to build on that knowledge. A version of the quiz show POINTLESS runs throughout the lesson and this maintains engagement whilst challenging the students to recall the parts of the chloroplast based on a description which is related to their function. The following structures are covered in this lesson: double membrane thylakoids (grana) stroma intergranal lamellae starch grains chloroplast DNA and ribosomes Once each structure has been recalled (or introduced) , a range of activities are used to ensure that key details are understood. As the main focus of the lesson is the reaction of photosynthesis, extra time is taken to introduce the details of the light-dependent and light-independent reactions that take place in the grana and stroma respectively. This includes descriptions of the role of the thylakoid membranes in the light-dependent reactions and the importance of ATP and reduced NADP for the reduction of GP to GALP in the Calvin cycle of the light-independent reactions. Links to other related topics are also made throughout and this is exemplified by the final task of the lesson where students are challenged on their recall of the structure, properties and function of starch (as originally covered in topic 1) As described above, this lesson has been specifically planned to prepare students for the upcoming lessons that cover the details of specification points 5.3 & 5.4 (i) and (ii).

This lesson describes the meaning of ecological terms and explains how biotic and abiotic factors control the distribution of organisms in a habitat. The engaging PowerPoint and accompanying resources have been designed to cover points 5.11, 5.12 and 5.13 in unit 4 of the Edexcel International A-level Biology (Salters Nuffield) specification and therefore cover the biological definitions of ecosystem, community, population and habitat. A quiz round called REVERSE Biology Bingo runs throughout the lesson and challenges students to recognise the following key terms from descriptions called out by the bingo caller: community ecosystem abiotic factor photosynthesis respiratory substrate biomass calorimetry distribution niche The ultimate aim of this quiz format is to support the students to understand that any sugars produced by photosynthesis that are not used as respiratory substrates are used to form biological molecules that form the biomass of a plant and that this can be estimated using calorimetry. Links are made to photosynthesis and net primary productivity as these will be met later in topic 5 as well as challenging their prior knowledge of adaptations, heterozygosity index classification and biological molecules. The final part of the lesson uses an exam-style question to get the students to recognise that biotic and abiotic factors control the distribution of organisms in a habitat and to recall the concept of niche.

This fully-resourced lesson describes how polygenic inheritance gives rise to phenotypes that show continuous variation. The engaging PowerPoint and accompanying resources have been primarily designed to cover points 3.20 (i) & 3.21 of the Edexcel International A-level Biology specification but also includes activities to challenge the students on previous concepts in topics 3 and 2. The students begin the lesson by having to identify phenotype and species from their respective definitions so that a discussion can be encouraged where they will recognise that phenotypic variation within a species is due to both genetic and environmental factors. The main part of the the lesson focuses on these genetic factors, and describes how mutation and the events of meiosis contribute to this variation. A range of activities, which include exam-style questions and quick quiz rounds, are used to challenge the students on their knowledge and understanding of substitution mutations, deletions, insertions, the genetic code, crossing over and independent assortment. Moving forwards, the concept of multiple alleles is introduced and students will learn how the presence of more than 2 alleles at a locus increases the number of phenotypic variants. Another quick quiz round is used to introduce polygenic inheritance and the link is made between this inheritance of genes at a number of loci as an example of continuous variation. The final part of the lesson describes a few examples where environmental factors affect phenotype, such as chlorosis in plants. As this is the final lesson in topic 3, the numerous activities can be used for revision purposes and to demonstrate the links between different biological topics.

This fully-resourced lesson describes the structure of the cell surface membrane and references Singer and Nicholson’s fluid mosaic model. The detailed and engaging PowerPoint and accompanying resources have been designed to cover specification point 4.2 (i) of the Edexcel A-level Biology B specification and also makes clear links are made to related topics such as the binding of hormones as covered in topic 9 and the electron transport chain as covered in topic 5. The fluid mosaic model is introduced at the start of the lesson so that it can be referenced at appropriate points throughout the lesson. Students were introduced to phospholipids in topic 1 and an initial task challenges them to spot the errors in a passage describing the structure and properties of this molecule. This reminds them of the bilayer arrangement, with the hydrophilic phosphate heads protruding outwards into the aqueous solutions on the inside and the outside of the cell. In a link to some upcoming lessons on the transport mechanisms, the students will learn that only small, non-polar molecules can move by simple diffusion and that this is through the tails of the bilayer. This introduces the need for transmembrane proteins to allow large or polar molecules to move into the cell by facilitated diffusion and active transport. Proteins that act as receptors as also introduced and an opportunity is taken to make a link to topic 9 so that students can understand how hormones or drugs will bind to target cells in this way and cause the release of cAMP on the interior of the cell. Moving forwards, the structure of cholesterol is covered and students will learn that this hydrophobic molecule sits in the middle of the tails and therefore acts to regulate membrane fluidity. The final part of the lesson challenges the students to apply their newly-acquired knowledge to a series of questions where they have to explain why proteins may have moved when two cells are used and to suggest why there is a larger proportion of these proteins in the inner mitochondrial membrane than the outer membrane.

This lesson describes the light-independent reactions of photosynthesis as the reduction of carbon dioxide using the products of the light-dependent reactions. The detailed PowerPoint and accompanying resources have been designed to cover point 5.4 (i) of the Edexcel International A-level Biology specification and this means that it describes carbon fixation in the Calvin cycle and the roles of GP, GALP, RuBP and RUBISCO. The lesson begins with an prior knowledge check where the students are challenged to recall the names of structures, substances and reactions from the light-dependent stage in order to reveal the abbreviations of the main 3 substances in the light-independent stage. This immediately introduces RuBP, GP and GALP and students are then shown how these substances fit into the cycle. The main section of the lesson focuses on the three phases of the Calvin cycle and time is taken to explore the key details of each phase and includes: The role of RUBISCO in carbon fixation The role of the products of the light-dependent stage, ATP and reduced NADP, in the reduction of GP to GALP The use of the majority of the GALP in the regeneration of RuBP . A step-by-step guide, with selected questions for the class to consider together, is used to show how 6 turns of the cycle are needed to form the GALP that will then be used to synthesise 1 molecule of glucose. A series of exam-style questions are included at appropriate points of the lesson and this will introduce limiting factors as well as testing their ability to answer questions about this stage when presented with an unfamiliar scientific investigation. The mark schemes are included in the PowerPoint so students can assess their understanding and any misconceptions are immediately addressed. This lesson has been specifically written to tie in with the previous lessons on the structure of a chloroplast and the light-dependent reactions as well as the upcoming lesson on the products of the light-independent reactions.

This fully-resourced lesson describes how isolation reduces gene flow between populations which leads to allopatric and sympatric speciation. The engaging PowerPoint and accompanying resources have been designed to cover point 5.24 of unit 4 of the Edexcel International A-level Biology specification and uses a range of real life examples to increase the relevance and to deepen student understanding The lesson begins by using the example of a hinny, which is the hybrid offspring of a horse and a donkey, to challenge students to recall the biological classification of a species. Moving forwards, students are introduced to the idea of speciation and the key components of this process, such as isolation and selection pressures, are covered and discussed in detail. Understanding and prior knowledge checks are included throughout the lesson to allow the students to not only assess their progress against the current topic but also to make links to earlier topics in the specification. Time is taken to look at the details of allopatric speciation and how the different mutations that arise in the isolated populations and genetic drift will lead to genetic changes. The example of allopatric speciation in wrasse fish because of the isthmus of Panama is used to allow the students to visualise this process. The final part of the lesson considers sympatric speciation and again a wide variety of tasks are used to enable a deep understanding to be developed.

This lesson describes how the surfaces in insects, fish and mammals are adapted for gas exchange. The PowerPoint and accompanying worksheets have been designed to cover the detail of point 4.3 (i) of the Edexcel A-level Biology B specification. The lesson has been intricately planned to challenge the students on their understanding of the surface area to volume ratio (as covered in topic 4.1) and to make direct links to upcoming lessons on the transport systems in humans. The lesson begins by explaining that single-celled organisms are able to diffuse oxygen and carbon dioxide across their body surface but that as organisms increase in size and their SA/V ratio decreases, they need adaptations at their gas exchange surfaces to be able to obtain the oxygen to meet their metabolic demands. This leads into the next part of the lesson which describes the roles of the following structures in insects and bony fish: spiracles, tracheae, tracheoles and tracheole fluid operculum, gill arch, gill filaments and lamellae The next task challenges the students to use their knowledge of topics 1, 2 and 3 to come up with the letters that form the key term, countercurrent flow. This is a key element of the lesson and tends to be a principle that is poorly understood, so extra time is taken to explain the importance of this mechanism. Students are shown two diagrams, where one contains a countercurrent system and the other has the two fluids flowing in the same direction, and this is designed to support them in recognising that this type of system ensures that the concentration of oxygen is always higher in the oxygenated water than in the blood in the lamellae. As the alveoli as a structure of gas exchange was introduced at GCSE, this final part of the lesson has been written to challenge the recall of that knowledge and to build on it. The main focus is the type of epithelium found lining the alveoli and students will discover that a single layer of flattened cells known as simple, squamous epithelium acts to reduce the diffusion distance. Again, students will have met this in a lesson in topic 2 on specialised cells (and tissues) so a number of prior knowledge checks are used alongside current understanding checks. The following features of the alveolar epithelium are also covered: Surface area Moist lining Production of surfactant The maintenance of a steep concentration gradient As a constant ventilation supply is critical for the maintenance of the steep concentration gradient, the final task considers the mechanism of ventilation

This lesson describes the structure and localised function of the frontal, occipital, temporal and parietal lobes of the cerebrum. The PowerPoint and accompanying resources are part of the 2nd lesson in a series of 17 lessons that cover the details of the brain and neuropsychology topic of the AQA GCSE Psychology specification. In the previous lesson, the students were introduced to the cerebrum as two hemispheres connected by the corpus callosum. This lesson builds on this by introducing the cerebral cortex as the outer layer which is divided into four lobes in each hemisphere. A series of quizzes are used throughout the lesson to introduce key terms in an engaging and (hopefully) memorable way, and through one quiz, the students will discover the names of the 4 lobes and recognise where they are located. Moving forward, students will learn about the function of each lobe, including the localised function of the motor, somatosensory, visual, auditory, Broca’s and Wernicke’s areas. This topic of the brain and neuropsychology has proved particularly difficult for the students in recent years, so I have taken time to analyse the lesson sequencing. There’s a lot of content to absorb and to understand before moving onto the next part, so I’ve tried to ensure that cross topics links and prior knowledge checks run throughout the lessons. I have organised the lessons to run through the biology content first before moving onto the psychology parts as shown by the 17 lessons below: #1 Organisation of the nervous system #2 The structure and function of the cerebral lobes #3 The cerebellum #4 The structure and function of the sensory and motor neurones #5 The relay neurones #6 Synaptic transmission #7 Excitation and inhibition at the synapse #8 The somatic nervous system #9 The autonomic nervous system #10 The fight or flight response #11 James-Lange theory of emotion #12 James-Lange theory of emotion part 2 #13 Penfield’s study of the interpretative index #14 Hebb’s theory of learning and neuronal growth #15 An introduction to neuropsychology #16 Brain scanning techniques #17 Tulving’s gold memory study

This lesson describes the actions of the sympathetic and parasympathetic divisions of the ANS. The PowerPoint and accompanying resources are part of the 8th lesson in a series of 17 lessons that cover the details of the brain and neuropsychology topic of the AQA GCSE Psychology specification. The students were introduced to the autonomic nervous system (ANS) in the 1st lesson in this topic, so this lesson has been designed to deepen and further their understanding of the actions of this system. Students will come to understand that the sympathetic division is most active during times of stress whilst the parasympathetic division is most active during times of sleep and relaxation. Through a series of tasks including a fun quiz round, they will discover the actions of the two divisions and then be challenged to apply their understanding. This topic of the brain and neuropsychology has proved particularly difficult for the students in recent years, so I have taken time to analyse the lesson sequencing. There’s a lot of content to absorb and to understand before moving onto the next part, so I’ve tried to ensure that cross topics links and prior knowledge checks run throughout the lessons. I have organised the lessons to run through the biology content first before moving onto the psychology parts as shown by the 17 lessons below: #1 Organisation of the nervous system #2 The structure and function of the cerebral lobes #3 The cerebellum #4 The structure and function of the sensory and motor neurones #5 The relay neurones #6 Synaptic transmission #7 Excitation and inhibition at the synapse #8 The autonomic nervous system #9 The fight or flight response #10 The somatic nervous system #11 James-Lange theory of emotion #12 James-Lange theory of emotion part 2 #13 Penfield’s study of the interpretative index #14 Hebb’s theory of learning and neuronal growth #15 An introduction to neuropsychology #16 Brain scanning techniques #17 Tulving’s gold memory study

This lesson describes how large molecules are hydrolysed to smaller molecules by the enzymes produced by the digestive system in mammals. The detailed PowerPoint and accompanying worksheets are part of the 1st lesson in a series of 2 which have been designed to cover the content of point 3.3 of the AQA A-level Biology specification and this lesson includes descriptions of the action of amylase, disaccharidases, lipase, endopeptidases, exopeptidases and dipeptidases. The lesson has been designed to walk the students through the functions of the digestive system at each point of the digestive tract up until the duodenum and focuses on the action of the enzymes produced in the mouth, stomach and small intestine and by the accessory organs of the system. Time is taken to describe and explain key details, such as the fact that endopeptidases cleave peptide bonds within the molecules, meaning that they cannot break down proteins into monomers. The lesson is filled with exam-style questions which will develop their understanding of the current topic as well as checking on their knowledge of related topics which have been previously-covered such as the structure of the biological molecules and qualitative tests. In addition to the detailed content and regular questioning, the lesson PowerPoint contains guided discussion periods and two quick quiz competitions which introduce a key term and a key value in a fun and memorable way This lesson has been specifically planned to prepare the students for the very next lesson where the mechanisms for the absorption of the products of digestion are described.

This detailed and engaging lesson describes how the passive transport of water molecules is brought about by osmosis. The PowerPoint and accompanying resources have been designed to cover the second part of specification point 4.2 (ii) as detailed in the Edexcel A-level Biology B specification and water potential is included throughout which will help students to prepare for core practical 6 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 between cells and a solution when these animal and plant cells are suspended in hypotonic, hypertonic or isotonic solutions.

This fully-resourced lesson describes the role of mitosis and the cell cycle in producing genetically identical daughter cells. The detailed PowerPoint and accompanying resources have been designed to cover point 3.14 of the Edexcel International A-level Biology specification and explains the importance of these cells for growth and asexual reproduction. In an earlier lesson covering meiosis (3.10), students were introduced to the different phases and structures involved in the cycle so this lesson builds on that by providing greater detail of the key events in each phase. Beginning with a focus on interphase, the importance of DNA replication is explained so that students can initially recognise that there are pairs of identical sister chromatids and then can understand how they are separated later in the cycle. A quiz competition has been written into the lesson and this runs throughout, challenging the students to identify the quantity of DNA in the cell (in terms of n) at different points of the cycle. The main part of the lesson focuses on prophase, metaphase, anaphase and telophase and describes how the chromosomes behave in these stages. Students will understand how the cytoplasmic division that occurs in cytokinesis results in the production of genetically identical daughter cells. This leads into 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 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 engaging lesson describes the myogenic stimulation of the heart and focuses on the roles of the SAN, AVN and bundle of His. The PowerPoint and accompanying resources have been designed to cover the point 4.4 (iv) of the Edexcel A-level Biology B specification but also describes the role of the Purkyne fibres. The lesson begins with the introduction of the SAN as the natural pacemaker and then time is given to study each step of the conduction of the impulse as it spreads away from the myogenic tissue in a wave of excitation. The lesson has been written to make clear links to the cardiac cycle and the structure of the heart and students are challenged on their knowledge of this system from earlier in the topic. Moving forwards, students are encouraged to consider why a delay would occur at the AVN and then they will learn that the impulse is conducted along the Bundle of His to the apex so that the contraction of the ventricles can happen from the bottom upwards. The structure of the cardiac muscle cells is discussed and the final task of the lesson challenges the students to describe the conducting tissue, with an emphasis on the use of key terminology.

This is a fully-resourced lesson that covers the details of specification point 5.1.2 (e) of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply an understanding of the effects of kidney failure and its potential treatments. This lesson consists of an engaging PowerPoint (55 slides) and associated differentiated worksheets that look at the diagnosis of a number of different kidney-related conditions and the potential treatments for kidney failure. This lesson is designed to get the students to take on the numerous roles of a doctor who works in the renal ward which include testing, diagnosis and treatment. Having obtained measurements by GFR and results by taking urine samples, hey are challenged to use their knowledge of the function of the kidney to study urine samples (and the accompanying GP’s notes) to diagnose one of four conditions. They then have to write a letter to the patient to explain how they made this diagnosis, again focusing on their knowledge of the structure and functions of the Bowman’s capsule and PCT. The rest of the lesson focuses on haemodialysis, peritoneal dialysis and kidney transplant. There are regular progress checks throughout the lesson so that students can assess their understanding and there are a number of homework activities included in the lesson. This lesson is designed for A-level students who are studying the OCR A-level Biology specification and ties in nicely with the other uploaded lessons on this organ which include the structure and function of the nephron, ultrafiltration, selective reabsorption and osmoregulation.

This is a fully-resourced lesson which covers the detail of point 5.1.3 (b) of the OCR A-level Biology A specification which states that students should be able to apply their understanding of the structures and functions of sensory, relay and motor neurones as well as the differences between myelinated and unmyelinated neurones. 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 look at the importance of the myelin sheath for the sensory and motor neurones. Students will be introduced to the need for the entry of ions to cause depolarisation and will learn that this is only possible at the nodes of Ranvier when there is a myelin sheath. Key terminology such as saltatory conduction is introduced and explained. The final task involves a comparison between the three neurones to check that the students have understood the structures and functions of the neurones. Throughout the lesson, links are made to the upcoming topic of the organisation of the nervous system (5.1.5) and students will be given additional knowledge such as the differences between somatic and autonomic motor neurones. This lesson has been designed for students studying on the OCR A-level Biology A course.

This fully-resourced lesson covers the content of the first part of specification point 5.1.3 (d) of the OCR A-level Biology A specification that states that students should be able to demonstrate and apply an understanding of the structures and roles of synapses in nervous transmission. The majority of the lesson uses the cholinergic synapse as the example but other neurotransmitters are considered to provide the students with a wider view of this topic. The lesson begins by using a version of the WALL (as shown in the cover image) which asks the students to group 12 words into three groups of 4. Not only will this challenge their prior knowledge from topics earlier in this module 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 aectylcholine 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 specification 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 has been designed for students studying the OCR A-level Biology A course but could be used with very able GCSE students who are keen to develop their understanding of synapses over and above the small detail that is provided at that level. This lesson also ties in nicely with the other uploaded lessons from module 5.1.3 (neuronal communication) which are sensory receptors, neurones, nerve impulses and summation.

This fully-resourced lesson provides examples of anatomical, behavioural and physiological adaptations of organisms to their environment. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 4.19 in unit 2 of the Edexcel International A-level Biology specification and also describes the concept of a niche and makes continual links to related topics such as natural selection 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.

This lesson describes the meaning of the term stem cell and the differences between totipotent, pluripotent and multipotent stem cells. The PowerPoint and accompanying worksheets have been designed to cover points 7.3 (i) and (ii) of the Edexcel A-level Biology B specification meaning that this lesson also contains discussion periods about the potential opportunities to use stem cells from embryos in medicine. The lesson begins with a knowledge recall of the structure of eukaryotic cells and the students have to use the first letters of each of the four answers to reveal the key term, stem cell. Time is then taken to consider the meaning of cellular differentiation, and this leads into the key idea that not all stem cells are equal when it comes to the number of cell types that they have the potential to differentiate into. A quick quiz round introduces the five degrees of potency, and then the students are challenged to use their understanding of terminology to place totipotency, pluripotency, multipotency, oligopotency and unipotency in the correct places on the potency continuum. Although the latter two do not have to be specifically known based on the content of specification point 7.3 (i), an understanding of their meaning was deemed helpful when planning the lesson as it should assist with the retention of knowledge about totipotency, pluripotency and multipotency. These three highest degrees of potency are the main focus of the lesson, and key details are emphasised such as the ability of totipotent cells to differentiate into any extra-embroyonic cell, which the pluripotent cells are unable to do. The morula, and inner cell mass and trophoblast of the blastocyst are used to demonstrate these differences in potency. The final part of the lesson discusses the decisions that the scientific community have to make about the use of pluripotent embryonic stem cells, adult stem cells and also multipotent foetal stem cells As there is a heavy mathematical content in the current A-level Biology exams, a Maths in a Biology context question is included in the lesson (when introducing the morula) to ensure that students continue to be prepared for the numerous calculations that they will have to tackle in the terminal exams. This resource has been differentiated two ways to allow students of differing abilities to access the work

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 lesson describes the role of the cardiovascular control centre in the medulla oblongata in the control of heart rate. The engaging and detailed PowerPoint and accompanying resources have been designed to cover the first part of point 7.13 (ii) of the Edexcel International A-level Biology specification and explains how this regulation enables the rapid delivery of oxygen and the removal of carbon dioxide. This lesson begins with a prior knowledge check where students have to identify and correct any errors in a passage about the conduction system of the heart. This allows the SAN to be recalled as this structure play an important role as the effector in this control system. Moving forwards, the three key parts of a control system are recalled as the next part of the lesson will specifically look at the range of sensory receptors, the coordination centre and the effector. Students are introduced to chemoreceptors and baroreceptors and time is taken to ensure that the understanding of the stimuli detected by these receptors is complete and that they recognise the result is the conduction of an impulse along a neurone to the brain. A quick quiz is used to introduce the medulla oblongata as the location of the cardiovascular centre. The communication between this centre and the SAN through the autonomic nervous system can be poorly understood so detailed explanations are provided and the sympathetic and parasympathetic divisions compared. The final task challenges the students to demonstrate and apply their understanding by writing a detailed description of the control and this task has been differentiated three ways to allow differing abilities to access the work