This lesson describes the main stages of mitosis and explains the significance of this type of nuclear division for the daughter cells produced by the cycle. The PowerPoint and accompanying resources have been designed to cover points 6 (a & b) in topic 6 of AS unit 1 of the WJEC A-level Biology specification and the process of cytokinesis is also described. Depending upon the exam board taken at GCSE, the knowledge and understanding of mitosis will differ considerably between students and there may be a number of misconceptions. This was considered at all points during the planning of the lesson so that existing errors are addressed and key points are emphasised throughout. Their understanding of interphase is challenged at the start of the lesson to ensure that they realise that it is identical pairs of sister chromatids that enter the M phase. The main part of the lesson focuses on prophase, metaphase, anaphase and telophase and describes how the chromosomes behave in these stages. There is a focus on the centrioles and the spindle fibres that they produce which contract to drag one chromatid from each pair in opposite directions to the poles of the cell. The remainder of the lesson is a series of understanding and application questions where students have to identify the various roles of mitosis in living organisms as well as tackling a Maths in a Biology context question. The lesson concludes with a final quiz round of MITOSIS SNAP where they only shout out this word when a match is seen between the name of a phase, an event and a picture.

This lesson describes the main stages of meiosis and has a specific focus on those events which contribute to genetic variation. The detailed PowerPoint and accompanying resources have been designed to cover point (d) in topic 6 of AS unit 1 of the WJEC A-level Biology specification and includes description of crossing over, independent assortment, independent segregation and the production of haploid gametes In order to understand how the events of meiosis like crossing over and independent assortment and independent segregation can lead to variation, students need to be clear in their understanding that DNA replication in interphase results in homologous chromosomes as pairs of sister chromatids. Therefore the beginning of the lesson focuses on the chromosomes in the parent cell and this first part of the cycle and students will be introduced to non-sister chromatids and the fact that they may contain different alleles which is important for the exchange that occurs during crossing over. Time is taken to go through this event in prophase I in a step by step guide so that the students can recognise that the result can be new combinations of alleles that were not present in the parent cell. Moving forwards, the lesson explores how the independent assortment and segregation of chromosomes and chromatids during metaphase I and II and anaphase I and II respectively results in genetically different gametes. The key events of all of the 8 phases are described and there is a focus on key terminology to ensure that students are able to describe genetic structures in the correct context. The final part of the lesson looks at the use of a mathematical expression to calculate the possible combinations of alleles in gametes as well as in a zygote following the random fertilisation of haploid gametes. Understanding and prior knowledge checks are interspersed throughout the lesson as well as a series of exam-style questions which challenge the students to apply their knowledge to potentially unfamiliar situations. This lesson has been specifically planned to lead on from the previous two lessons on the cell cycle and the main stages of mitosis and constant references are made throughout to encourage students to make links and also to highlight the differences between the two types of nuclear division

This lesson describes how tissue fluid is formed and reabsorbed in order to emphasise its importance as the link between the blood and cells. The PowerPoint and accompanying resources have been designed to cover point (h) in topic 3 of AS unit 2 of the WJEC A-level Biology specification and explains how a combination of the effects of hydrostatic pressure and oncotic pressure results in the formation of tissue fluid in animals. The lesson begins with an introduction to the arteriole and venule end of a capillary as these will need to be considered as separate entities when describing the formation of tissue fluid. A quick quiz competition introduces a value for the hydrostatic pressure at the arteriole end and students are challenged to first predict some parts of the blood will move out of the capillary as a result of the push from the hydrostatic pressure and this allows oncotic pressure to be initially explored. The main part of the lesson uses a step by step guide to describe how the net movement is outwards at the arteriole end before students will use this guidance to describe what happens at the venule end. In the concluding part of the lesson, students will come to recognise oedema as a condition where tissue fluid accumulates and they again are challenged to explain how this occurs before they finally learn how the fluid is returned to the circulatory system as lymph

This lesson describes the movement of water from the root to the leaf and includes the transpiration stream and the cohesion-tension theory. The PowerPoint and accompanying resources have been designed to cover point (n) of topic 3 in AS unit 2 of the WJEC A-level Biology specification This lesson has been written to follow on from a previous lesson, which finished with the description of the transport of the water and mineral ions from the endodermis to the xylem. Students are immediately challenged to use this knowledge to understand root pressure and the movement by mass flow down the pressure gradient. Moving forwards, time is taken to study the details of transpiration pull and the interaction between cohesion, tension and adhesion in capillary action is explained. Understanding is constantly checked through a range of tasks and prior knowledge checks are also written into the lesson to challenge the students to make links to previously covered topics such as the structure of the transport tissues. The final part of the lesson considers the journey of water through the leaf and ultimately out of the stomata in transpiration. A step by step guide using questions to discuss and answer as a class is used to support the students before the final task challenges them to summarise this movement out of the leaf.

This detailed lesson describes the absorption of water, the movement through the root and the role of the endodermis. Both the PowerPoint and accompanying resource have been designed to cover specification points (j, k & l) in topic 3 of AS unit 2 of the WJEC A-level Biology specification and includes descriptions of the apoplast, symplast and vacuolar pathways and the Casparian strip. The lesson begins by looking at the specialised features of the root hair cell so that students can understand how these epidermal cells absorb water and mineral ions from the soil. Moving forwards, students are introduced to key terminology such as epidermis and root cortex before time is taken to look at the different pathways that water and minerals use to transverse across the cortex. Discussion points are included throughout the lesson to encourage the students to think about each topic in depth and challenges them to think about important questions such as why the apoplast pathway is needed for the water carrying the ions. The main part of the lesson focuses on the role of the endodermis in the transport of the water and ions into the xylem. Students will be introduced to the Casparian strip and will learn how this layer of cells blocks the apoplast pathway. A step by step method using class questions and considered answers is used to guide them through the different steps and to support them when writing the detailed description. This lesson has been written to tie in with the next lesson on the pathways and mechanisms by which water and mineral ions are transported to the leaves.

This lesson outlines how bacteria become resistant to antiobiotics and discusses its consequences and the steps taken to reduce its impact. The PowerPoint and accompanying worksheet have been designed to cover specification points 10.2 (b & c) of the CIE A-level Biology specification President Trump’s error ridden speech about antibiotics is used at the beginning of the lesson to remind students that this is a treatment for bacterial infections and not viruses as he stated. Moving forwards, 2 quick quiz competitions are used to introduce MRSA and then to get the students to recognise that they can use this abbreviation to remind them to use mutation, reproduce, selection (and survive) and allele in their descriptions of the development of resistance by evolution through natural selection. The main task of the lesson challenges the students to form a description to explain how this strain of bacteria developed resistance to methicillin, making use of the five key terms emphasised above. Moving forwards, there is a focus on the hospital as the common location for MRSA infections and students will recognise that this opportunistic pathogen can infect through open wounds to cause sepsis and potentially death. Figures from infections and deaths in hospitals in the US are used to increase the relevance and students will learn how a MRSA prevention program in VHA facilities includes screening of surgery patients to try to reduce its impact. The lesson concludes with a discussion about other methods that can be used by hospitals and general practitioners to reduce the impact of MRSA and to try to prevent the development of resistance in other strains.

This lesson describes the development and spread of antibiotic resistance in bacteria and discusses the difficulties in controlling this spread. The PowerPoint and accompanying worksheet have been designed to cover specification points 6.4 (i & ii) of the Edexcel A-level Biology B specification President Trump’s error ridden speech about antibiotics is used at the beginning of the lesson to remind students that this is a treatment for bacterial infections and not viruses as he stated. Moving forwards, 2 quick quiz competitions are used to introduce MRSA and then to get the students to recognise that they can use this abbreviation to remind them to use mutation, reproduce, selection (and survive) and allele in their descriptions of the development of resistance by evolution through natural selection. The main task of the lesson challenges the students to form a description to explain how this strain of bacteria developed resistance to methicillin, making use of the five key terms emphasised above. Moving forwards, there is a focus on the hospital as the common location for MRSA infections and students will recognise that this opportunistic pathogen can infect through open wounds to cause sepsis and potentially death. Figures from infections and deaths in hospitals in the US are used to increase the relevance and students will learn how a MRSA prevention program in VHA facilities includes screening of surgery patients to try to reduce its impact. The lesson concludes with a discussion about other methods that can be used by hospitals and general practitioners to reduce the spread of MRSA and to try to prevent the development of resistance in other strains.

This lesson describes the structure and function of the human heart and names the blood vessels associated with this organ . The PowerPoint and accompanying resources are part of the first lesson in a series of 2 lessons that have been designed to cover point (b) in topic 3 of AS unit 2 of the WJEC A-level Biology specification As this topic was covered at GCSE, the lesson has been planned to build on this prior knowledge whilst adding the key details which will enable students to provide A-level standard answers. The primary focus is the identification of the different structures of the heart but it also challenges their ability to recognise the important relationship to function. For example, time is taken to ensure that students can explain why the atrial walls are thinner than the ventricular walls and why the right ventricle has a thinner wall than the left ventricle. Opportunities are taken throughout the lesson to link this topic to the others found in topic 3 including those which have already been covered like circulatory systems as well as those which are upcoming such as the initiation of heart action. There is also an application question where students have to explain why a hole in the ventricular septum would need to be repaired if it doesn’t naturally close over time.

This lesson describes the roles of the SAN and Purkyne fibres in the coordination of the three stages of the cardiac cycle. The PowerPoint and accompanying resources are part of the first lesson in a series of 2 lessons that have been designed to cover point [c] in topic 3 of AS unit 2 of the WJEC A-level Biology specification and has a specific focus on the pressure changes that occur in each stage of the cycle The start of the lesson introduces the cardiac cycle as well as the key term systole, so that students can immediately recognise that the three stages of the cycle are atrial and ventricular systole followed by diastole. Students are challenged on their prior knowledge of the structure of the heart as they have to name and state the function of an atrioventricular and semi-lunar valve from an internal diagram. This leads into the key point that pressure changes in the chambers and the major arteries results in the opening and closing of these sets of valves. Students are given a description of the pressure change that results in the opening of the AV valves and shown where this would be found on the graph detailing the pressure changes of the cardiac cycle. They then have to use this as a guide to write descriptions for the closing of the AV valve and the opening and closing of the semi-lunar valves and to locate these on the graph. By providing the students with this graph, the next part of the lesson can focus on explaining how these changes come about. Students have to use their current and prior knowledge of the chambers and blood vessels to write 4 descriptions that cover the cardiac cycle. This rest of the lesson focuses on the roles of the SAN and Purkyne fibres as well as the AVN and the bundle of His in the coordination of the heartbeat, continually linking back to the work on the cycle. The SAN is introduced 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. 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 lesson describes how the structure of arteries, arterioles, capillaries, venules and veins in the mammalian circulatory system relate to their functions. The PowerPoint and accompanying resources are part of the second lesson in a series of 2 lessons which have been designed to cover specification point (b) of topic 3 in AS unit 2 of the WJEC A-level Biology A specification. The first lesson in this series covers the structure and function of the human heart and its associated blood vessels This lesson has been written to build on any prior knowledge from GCSE or earlier in this topic to enable students to fully understand why a particular type of blood vessel has particular features. Students will be able to make the connection between the narrow lumen and elastic tissue in the walls of arteries and the need to maintain the high pressure of the blood. A quick version of the GUESS WHO game is used to introduce smooth muscle and collagen in the tunica media and externa and again the reason for their presence is explored and explained. Moving forwards, it is quite likely that some students will not be aware of the transition vessels that are the arterioles. This section begins with an understanding of the need for these vessels because the structural and functional differences between arteries and capillaries is too significant. The action of the smooth muscle in the walls of these vessels is discussed and students will be challenged to describe a number of situations that would require blood to be redistributed. The middle part of the lesson looks at the role of the capillaries in exchange and links are made to diffusion to ensure that students can explain how the red blood cells pressing against the endothelium results in a short diffusion distance. The remainder of the lesson considers the structure of the veins and students are challenged to explain how the differences to those observed in arteries is due to the lower blood pressure found in these vessels.

This lesson describes the Krebs cycle as a stage of aerobic respiration that liberates energy to produce ATP and reduced NAD and releases carbon dioxide. The PowerPoint and accompanying resource have been designed to cover specification point [c] in topic 3 of A2 unit 3 of the WJEC A-level Biology specification. 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 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 This lesson has been designed to tie in with the other uploaded lessons on glycolysis and the electron transport chain (in oxidative phosphorylation).

This lesson describes the concept of homeostasis using negative feedback control and also describes the role of positive feedback. The PowerPoint and accompanying resources have been designed to cover specification points (a & b) in topic 7 of A2 unit 3 of the WJEC A-level Biology specification and explains how this feedback control maintains systems within narrow limits but has also been planned to provide important details for upcoming topics such as osmoregulation. The normal ranges for blood glucose concentration, blood pH and body temperature are introduced at the start of the lesson to allow students to recognise that these aspects have to be maintained within narrow limits. A series of exam-style questions then challenge their recall of knowledge from AS units 1 & 2 and the earlier topics in A2 unit 3 as they have to explain why it’s important that each of these aspects is maintained within these limits. The students were introduced to homeostasis at GCSE, so this process is revisited and discussed, to ensure that students are able to recall that this is the maintenance of a state of dynamic equilibrium. A quick quiz competition is used to reveal negative feedback as a key term and students will learn how this form of control reverses the original change and biological examples are used to emphasise the importance of this system for restoring levels to the limits (and the optimum). The remainder of the lesson explains how positive feedback differs from negative feedback as it increases the original change and the role of oxytocin in birth and the movement of sodium ions into a neurone are used to exemplify the action of this control system.

This lesson describes sex linkage, focusing on the the inheritance of genes on the X chromosome that lead to haemophilia and Duchenne muscular dystrophy. The PowerPoint and accompanying resources have been designed to cover specification point [e] in topic 3 of A2 unit 4 of the WJEC A-level Biology specification. Key genetic terminology is used throughout and the lesson begins with a check on their ability to identify the definition of homologous chromosomes. Students will recall that the sex chromosomes are not fully homologous and that the smaller Y chromosome lacks some of the genes that are found on the X. This leads into one of the numerous discussion points, where students are encouraged to consider whether females or males are more likely to suffer from sex-linked diseases and they will be challenged to find evidence to support this decision later in the lesson. In terms of humans, the lesson focuses on haemophilia and a step-by-step guide is used to demonstrate how these specific genetic diagrams should be constructed and how the phenotypes should then be interpreted. The final tasks of the lesson challenge the students to carry out a dihybrid cross that involves a sex-linked disease and an autosomal disease before applying their knowledge to a question about chickens and how the rate of feather production in chicks can be used to determine gender. All of the tasks are differentiated so that students of differing abilities can access the work and all exam questions have fully-explained, visual markschemes to allow them to assess their progress and address any misconceptions

This lesson describes the effects of pH on the rate of an enzyme-catalysed reaction. The PowerPoint and accompanying resources are part of the second lesson in a series of 4 lessons which have been designed to cover the content of point 3.2 (a) of the CIE A-level Biology specification. The lesson begins with a short discussion, where the students are challenged to identify how the stomach and the small intestine differ in terms of a particular condition and to explain why the conditions in these neighbouring digestive organs are so important. This introduces pepsin and trypsin and these protease enzymes play a key role throughout the lesson as they are good examples of how different extracellular enzymes have different optimum pH values (which are not necessarily 7.0). Moving forwards, students will discuss how the rate of an enzyme-controlled reaction will change if there are small or large changes in pH, and then time is taken to ensure that students can explain these changes with reference to tertiary structure bonds and the shape of the active site. Through the use of a quick quiz competition, the students will be reminded of the key term “buffer” and a series of questions are used to challenge their understanding of how these substances could be used in a practical investigation. They will also learn how buffers are found in blood plasma as well as in red blood cells in the form of haemoglobin. As there is a considerable proportion of marks for Maths in a Biology context questions in the A-level assessments, the remainder of the lesson challenges the students to use a given formula to calculate the pH of blood when given the hydrogen ion concentration and to calculate percentage decrease. These questions have been differentiated to give assistance to those that need the support

This lesson describes the effects of pH on enzyme activity. The PowerPoint and accompanying resources are part of the first lesson in a series of 3 lessons which have been designed to cover the content of point 2.1.4 (d)(i)of the OCR A-level Biology A specification. The lesson begins with a short discussion, where the students are challenged to identify how the stomach and the small intestine differ in terms of a particular condition and to explain why the conditions in these neighbouring digestive organs are so important. This introduces pepsin and trypsin and these protease enzymes play a key role throughout the lesson as they are good examples of how different extracellular enzymes have different optimum pH values (which are not necessarily 7.0). Moving forwards, students will discuss how the rate of an enzyme-controlled reaction will change if there are small or large changes in pH, and then time is taken to ensure that students can explain these changes with reference to tertiary structure bonds and the shape of the active site. Through the use of a quick quiz competition, the students will be reminded of the key term “buffer” and a series of questions are used to challenge their understanding of how these substances could be used in a practical investigation. They will also learn how buffers are found in blood plasma as well as in red blood cells in the form of haemoglobin. With there being such a considerable proportion of marks for Maths in a Biology context questions in the A-level assessments, the remainder of the lesson challenges the students to use a given formula to calculate the pH of blood when given the hydrogen ion concentration and to calculate percentage decrease. These questions have been differentiated to give assistance to those that need the support Please note that this is a lesson which describes the effect on enzyme activity, as described in 2.1.4 (d)(i), and not the details of the practical investigation which is covered in a later lesson

This lesson describes the effects of pH on the rate of enzyme-controlled reactions. The PowerPoint and accompanying resources are part of the third lesson in a series of 5 lessons which have been designed to cover the content of point 1.4.2 (Many proteins are enzymes) of the AQA A-level Biology specification. The lesson begins with a short discussion, where the students are challenged to identify how the stomach and the small intestine differ in terms of a particular condition and to explain why the conditions in these neighbouring digestive organs are so important. This introduces pepsin and trypsin and these protease enzymes play a key role throughout the lesson as they are good examples of how different extracellular enzymes have different optimum pH values (which are not necessarily 7.0). Moving forwards, students will discuss how the rate of an enzyme-controlled reaction will change if there are small or large changes in pH, and then time is taken to ensure that students can explain these changes with reference to tertiary structure bonds and the shape of the active site. Through the use of a quick quiz competition, the students will be reminded of the key term “buffer” and a series of questions are used to challenge their understanding of how these substances could be used in a practical investigation. They will also learn how buffers are found in blood plasma as well as in red blood cells in the form of haemoglobin. With there being such a large proportion of marks for Maths in a Biology context questions in the AQA assessments, the remainder of the lesson challenges the students to use a given formula to calculate the pH of blood when given the hydrogen ion concentration and to calculate percentage decrease. These questions have been differentiated to give assistance to those that need the support