This detailed lesson describes how recombinant DNA is produced using restriction endonucleases and DNA ligase and is inserted into other cells. The engaging PowerPoint and accompanying resources have been designed to cover points 8.18 & 8.19 of the Edexcel International A-level Biology specification. The lesson begins with a definition of genetic engineering and recombinant DNA to allow students to begin to understand how this process involves the transfer of DNA fragments from one species to another. Links are made to the genetic code and transcription and translation mechanisms, which were met in topic 2, in order to explain how the transferred gene can be translated in the transgenic organism. Moving forwards, the method involving reverse transcriptase and DNA polymerase is introduced and their knowledge of the structure of the polynucleotides and the roles of enzymes is challenged through questions and discussion points. Restriction endonucleases are then introduced and time is taken to look at the structure of a restriction site as well as the production of sticky ends due to the staggered cut on the DNA. A series of exam-style questions with displayed mark schemes are used to allow the students to assess their current understanding. The second half of the lesson looks at the culture of transformed host cells as an in vivo method to amplify DNA fragments. Students will learn that bacterial cells are the most commonly transformed cells so the next task challenges their recall of the structures of these cells so that plasmid DNA can be examined from that point onwards. Time is taken to explore the finer details of each step such as the addition of the promoter and terminator regions, use of the same restriction enzyme to cut the plasmid as was used to cut the gene and the different types of marker genes. As well as understanding and prior knowledge checks, quick quiz competitions are used throughout the lesson to introduce key terms such as cDNA and EcoR1 in a fun and hopefully memorable way

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 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 how the cells of the proximal tubule in the nephron of the kidney are adapted for reabsorption. The PowerPoint and accompanying resource which is filled with tasks have been designed to cover specification point [e] in topic 7 of A2 unit 3 of the WJEC A-level Biology specification and builds on the knowledge gained in the previous lessons on the structure of the nephron and the functions of the mammalian kidney. The lesson begins by challenging the students to recall the substances that are found in the glomerular filtrate so that each of them can be considered over the course of the rest of the lesson. Moving forwards, the first of the numerous discussion points which are included in the lesson is used to get students to predict the component of the filtrate which won’t be found in the urine when they are presented with pie charts from each of these situations. Upon learning that glucose is 100% reabsorbed, along with most of the ions and some of the water, the rest of the lesson focuses on describing the relationship between the structure of the proximal tubule and the function of selective reabsorption. Again, this section begins by encouraging the students to discuss and to predict which structures they would expect to find in a section of the kidney if the function is to reabsorb. They are given the chance to see the structure (as shown in the cover image) before each feature is broken down to explain its importance. Time is taken to look at the role of the cotransporter proteins to explain how this allows glucose, along with sodium ions, to be reabsorbed from the lumen of the PCT into the epithelial cells. The final part of the lesson focuses on urea and how the concentration of this substance increases along the tubule as a result of the reabsorption of some of the water.

This fully-resourced lesson describes the range of potential treatments for kidney failure. The PowerPoint and accompanying resources have been designed to cover specification point (h) in topic 7 of A2 unit 3 of the WJEC A-level Biology specification. This lesson involves 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 describes the inheritance of two genes and guides students through the calculation of phenotypic ratios, before considering linkage. The PowerPoint and the accompanying resources have been designed to cover point [c] in topic 3 of A2 unit 4 of the WJEC A-level Biology specification. As the previous lesson described the construction of genetic crosses and pedigree diagrams, students are aware of the methods involved in writing genotypes and gametes for the inheritance of a single gene. Therefore, the start of this lesson builds on this understanding to ensure that students recognise that genotypes contain 4 alleles and gametes contain 2 alleles when two genes are inherited. The students are taken through the steps of a worked example to demonstrate the key steps in the calculation of a phenotypic ratio before 2 exam-style questions challenge them to apply their newly-acquired knowledge. Mark schemes are displayed within the PowerPoint to allow students to assess their progress. The phenotypic ratio generated as the answer to the next question is 9:3:3:1 and time is taken to explain that this is the expected ratio when two heterozygotes for two unlinked genes are crossed which they may be expected to use when meeting the chi squared test in an upcoming lesson The remainder of the lesson considers how linkage, where two genes have loci on the same chromosome, affects the outcome of dihybrid inheritance. This is a difficult topic which can be poorly understood by students so extra time was taken during the planning to split the concept into small chunks. There is a clear focus on using the number of parent phenotypes and recombinants in the offspring as a way to determine linkage and suggest how the loci of the two genes compare. Important links to other topics such as crossing over in meiosis are made to enable students to understand how the random formation of the point of contact (chiasma) determines whether new phenotypes will be seen in the offspring or not. Linkage is an important cause of variation and the difference between observed and expected results and this is emphasised on a number of occasions and a link to the chi squared test which is covered in an upcoming lesson is also made. The main task of the lesson act as understanding check where students are challenged to analyse the results of genetic crosses involving the inheritance of the ABO blood group gene and the nail-patella syndrome gene n humans and also the inheritance of body colour and wing length in Drosophila.

This lesson guides students through the use of a chi-squared test to determine the significance of the difference between observed and expected results. It is fully-resourced with a detailed PowerPoint and differentiated worksheets that have been designed to cover point (d) in topic 3 of A2 unit 4 of the WJEC A-level Biology specification The lesson includes a step-by-step guide to demonstrates how to carry out the test in small chunks. At each step, time is taken to explain any parts which could cause confusion and helpful hints are provided to increase the likelihood of success in exam questions on this topic. Students will understand how to use the phenotypic ratio to calculate the expected numbers and then how to find the critical value in order to compare it against the chi-squared value. A worked example is used to show the working which will be required to access the marks and then the main task challenges the students to apply their knowledge to a series of questions of increasing difficulty. This lesson has been specifically designed to tie in with the previous lessons in this topic as there are regular references to dihybrid inheritance as well as to topics in the AS units like meiosis

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

A highly engaging lesson that looks at the structures that are found in the 1st line of defence and explores the methods of action use by phagocytes and lymphocytes. This lesson has been designed for GCSE students but could be used as an initial recap with A-level students before they go on to learn this topic in greater detail The lesson begins by introducing the meaning of the 1st line of defence. A quick competition is used to challenge the students to recognise the names of some of these structures when their names have some letters missing. Time is taken to discuss the action of the cilia and skin and then students are challenged to make links to the related topics of enzymes and pH as they complete a passage about the role of hydrochloric acid in the stomach. Moving forwards, students will learn that there are two types of white blood cells, phagocytes and lymphocytes, and the details of their actions is explored. Key points such as the specificity of antibodies and the involvement of enzymes are discussed in detail so that this topic can be understood to the depth needed at this level. In addition to a number of games to maintain engagement, progress checks are written into this at regular intervals to allow the students to assess their understanding.

This is a fully-resourced lesson, designed for GCSE students, that lteaches students how to prove that mass is conserved in a chemical reaction and guides them in the explanation of why some reactions do not give equal masses when measured. The lesson begins by introducing the law of the conservation of mass. Students will learn that they can expect questions which challenge them to prove that mass is conserved through the use of the relative formula mass. Therefore, the next section of the lesson focuses on the skills associated with this calculation and looks at more different formulae such as those with brackets. Students are given an opportunity to check their skills before trying to prove mass is conserved in three chemical reactions. All questions have displayed mark schemes so that students can assess their understanding. The rest of the lesson looks at instances of when the mass of the reactants does not equal the mass of the products. A practical method for the decomposition of copper carbonate is provided if the teacher wants to use it, so that students can collect results which show this difference in mass. Discussions are encouraged in order to get students to offer explanations as to why the mass of the products is lower. Once the gas has been identified, students are further challenged to consider apparatus that could be used to collect and record the results to again prove conservation.

A fully-resourced lesson that uses a range of tasks, understanding checks and quick competitions to guide students through calculating the relative formula mass for substances with a range of chemical formulae. The relative formula mass is required in a lot of calculations, such as those that involve moles, so it is an important skill to get right. Worked examples are used throughout the lesson to visualise the metho for the students. Initially, students will learn how to calculate the mass from simple formulae before helpful hints are provided for harder formulae such as those that contain a bracket. Students are given the chance to apply their knowledge by proving that mass is conserved in a reaction. This lesson has been written for GCSE students but could be used with higher ability KS3 students in lessons that are looking to push knowledge forward