This detailed and engaging lesson focuses on the importance of the excretion of carbon dioxide and urea in humans. It also looks at how the urea is formed as a result of deamination in the liver and as such covers the Core and Supplement content of the early section of topic 13 of the CIE IGCSE Biology specification. The lesson begins with a “Crack the code” type task which will enable the students to learn the meaning of excretion and specifically how it relates to the products of metabolism. Excretion is often confused with egestion by students so this misconception is addressed immediately and as a result they will understand that carbon dioxide and urea have to be excreted whereas faeces is egested. Moving forwards, time is taken to explain why carbon dioxide needs to be excreted and links are made to the earlier topic of enzymes and how a fall in pH could affect their activity. The rest of the lesson focuses on the formation of urea in the liver. Whilst learning about deamination, students will also be introduced to the process of assimilation and the production of rge plasma protein fibrinogen is used to explain the importance of this function of the liver. In addition to understanding checks and prior knowledge checks, quiz competitions are included in the lesson to introduce key terms in a fun and memorable way. This lesson has been designed for students studying the CIE IGCSE Biology course but is also suitable for older students who are starting the topic of excretion or the functions of the liver and want to recall the key facts.

This lesson describes how the structure of the mammalian lung is adapted for rapid gaseous exchange. The engaging PowerPoint has been designed to cover point 2.1 (iii) of the Edexcel International A-level Biology specification and focuses on the essential features of the alveolar epithelium as well as the mechanism of ventilation to maintain a steep concentration gradient for the simple diffusion of oxygen and carbon dioxide. Gas exchange at the alveoli is a topic that was covered at GCSE and considered during the previous lessons in topic 2.1 so this lesson has been written to challenge the recall of that knowledge and to build on it. The main focus of the first half of the lesson 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. The following features of the alveolar epithelium are also covered: Surface area Moist lining Production of surfactant The maintenance of a steep concentration gradient is the role of the respiratory system and the next part of the lesson focuses on the diaphragm and intercostal muscles. As the mechanism of inhalation is a cascade of events, the details of this process are covered in a step by step format using bullet points. At each step, time is taken to discuss the key details which includes an introduction to Boyle’s law that reveals the inverse relationship between volume and pressure. It is crucial that students are able to describe how the actions of the diaphragm, external intercostal muscles and ribcage result in an increased volume of the thoracic cavity and a subsequent decrease in the pressure, which is below the pressure outside of the body. At this point, their recall of the structures of the mammalian gas exchange system is tested, to ensure that they can describe the pathway the air takes on moving into the lungs.

An engaging lesson presentation (16 slides) which looks at the surface area to volume ratio and ensures that students can explain why this factor is so important to the organisation of living organisms. This is a topic which is generally poorly misunderstood by students and therefore time has been taken to design an engaging lesson which highlights the key points in order to encourage greater understanding. The lesson begins by showing students the dimensions of a cube and two answers and challenges them to work out what the questions were that produced these answers. Students are shown how to calculate the surface area and the volume of an object before it is explained how this can then be turned into a ratio. Time is taken at this point to ensure that students can apply this new-found knowledge as they have to work out which of the three organisms in the “SA: V OLYMPICS” would stand aloft the podium. Students are given the opportunity to draw conclusions from this task so that they can recognise that the larger the organism, the lower the surface area to volume ratio. The lesson finishes by explaining how larger organisms, like humans, have adapted in order to increase the surface area at important exchange surfaces in their bodies. There are regular progress checks throughout the lesson to allow the students to check on their understanding. This lesson has been written for GCSE students but is perfectly suitable for A-level students who want to look at this topic from a basic level

A fully-resourced lesson which has been designed for GCSE students and includes an engaging lesson presentation and associated worksheets. This lesson looks at the three limiting factors of photosynthesis, focusing on the graphs that they produce and ensures that students can explain why temperature is a factor. This lesson begins by introducing the students to the definition of a limiting factor. They are challenged to recognise that it would be photosynthesis which is limited by carbon dioxide concentration and light intensity. The third factor, temperature, is not introduced until later in the lesson so that students are given thinking time to consider what it might be. Having been presented with two sets of data, students are asked to draw sketch graphs to represent the trend. The limiting factors on the light intensity graph are taught to the students so they can use this when working out the limiting factors on the carbon dioxide graph. The remainder of the lesson focuses on temperature and more specifically why a change in this factor would cause a change in the rate of photosynthesis because of enzymes. The student’s knowledge of that topic is tested alongside. Progress checks have been written into the lesson at regular intervals so that students can constantly assess their understanding.

A fully-resourced lesson that includes a lesson presentation (20 slides) and a differentiated worksheet. The lesson uses a step-by-step method to guide students through the process of writing net ionic equations. Students will learn the meaning of a spectator ion and be able to identify them within an equation so that they can be removed when writing the final net ionic equation. The lesson focuses on writing these equations for neutralisation and precipitation reactions, with the former being a very common question in assessments. This lesson has been written for GCSE students (14 - 16 year olds)

This lesson describes the principles of cell fractionation and ultracentrifugation as used to separate cell components. The engaging PowerPoint and accompanying resources are part of the final lesson in a series of 4 lessons which have been planned to cover the details of point 2.1.3 of the AQA A-level biology specification. This lesson begins by informing the students that several of the key terms in this lesson, including the lesson title, end in -ation, and therefore they have to use the clues to work out that the 1st one is cell fractionation. A quiz round like this runs throughout the lesson, introducing homogenisation, filtration and ultracentrifugation in a memorable way. Time is taken to explain each of the processes in detail, and where possible, links are made to previously covered content as well as content that will be met in future lessons. For example, students will learn that the solution must be kept ice-cold and isotonic, and they are challenged to recognise that the low temperature is to reduce the activity of potentially damaging enzymes, before being told that there will be no net movement of water by osmosis because of the isotonic solution. The answers to all understanding and prior knowledge checks are embedded into the PowerPoint to allow students to assess their progress. When explaining the process of ultracentrifugation, the students are given an opportunity to predict which of 6 listed organelles will be found in the 1st pellet because it is the heaviest, right down to the lightest organelle. The lesson finishes with several exam-style questions to check that they’ve understood this separation technique and have a strong knowledge of cells and their organelles. This lesson has been planned to continously link with the other lessons in topic 2.1 (Cell structure).

This fully-resourced lesson describes the ultrastructure of an eukaryotic cell and describes the relationship between the structure and function of the organelles. The detailed and engaging PowerPoint and accompanying resources have been designed to cover point 2.1 (v) of the Edexcel A-level Biology B specification As cells are the building blocks of living organisms, it makes sense that they would be heavily involved in all of the 10 topics in the Edexcel A-level B course and intricate planning has ensured that links are made to topic 1 and details are provided to link to the upcoming topics. A wide range of activities, that include exam-style questions, class discussion points and quick quiz competitions, will maintain motivation and engagement whilst covering the finer details of the following structures and organelles: nucleus nucleolus ribosomes rough endoplasmic reticulum Golgi apparatus lysosomes smooth endoplasmic reticulum mitochondria cell surface membrane centrioles vacuole (+ tonoplast) chloroplasts cell wall As mentioned above, all of the worksheets have been differentiated to support students of differing abilities whilst maintaining challenge Due to the detail that is included in this lesson, it is estimated that it will take in excess of 3 hours of allocated A-level teaching time to cover the work

This lesson explains the effects of temperature on the rate of enzyme activity and describes how to calculate the temperature coefficient. The PowerPoint and the accompanying resources have been designed to cover point 5.21 of the Edexcel International A-level Biology specification and this lesson has been specifically planned to tie in with a lesson in topic 2 where the roles and mechanism of action of enzymes were introduced. The lesson begins by challenging the students to recognise optimum as a key term from its 6 synonyms that are shown on the board. Time is taken to ensure that the students understand that the optimum temperature is the temperature at which the most enzyme-product complexes are produced per second and therefore the temperature at which the rate of an enzyme-controlled reaction works at its maximum. The optimum temperatures of DNA polymerase in humans and in a thermophilic bacteria and RUBISCO in a tomato plant are used to demonstrate how different enzymes have different optimum temperatures and the roles of the latter two in the PCR and photosynthesis are briefly described to prepare students for these lessons in modules 6 and 5. Moving forwards, the next part of the lesson focuses on enzyme activity at temperatures below the optimum and at temperatures above the optimum. Students will understand that increasing the temperature increases the kinetic energy of the enzyme and substrate molecules, and this increases the likelihood of successful collisions and the production of enzyme-substrate and enzyme-product complexes. When considering the effect of increasing the temperature above the optimum, continual references are made to the previous lesson and the control of the shape of the active site by the tertiary structure. Students will be able to describe how the hydrogen and ionic bonds in the tertiary structure are broken by the vibrations associated with higher temperatures and are challenged to complete the graph to show how the rate of reaction decreases to 0 when the enzyme has denatured. The final part of the lesson introduces the Q10 temperature coefficient and students are challenged to apply this formula to calculate the value for a chemical reaction and a metabolic reaction to determine that enzyme-catalysed reactions have higher rates of reaction

This fully-resourced lesson describes how rod cells in the mammalian retina detect stimuli to allow vision in low light intensity. The detailed PowerPoint and accompanying resources have been designed to cover the second part of point 8.5 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and includes reference to the roles of rhodopsin, opsin, retinal, sodium ions, cation channels and hyperpolarisation in the formation of action potentials in the optic neurones. It is likely that students will be aware that the human retina contains rod and cone cells, so this lesson builds on that knowledge and adds the detail needed at this level. Students will discover that the optical pigment in rod cells is rhodopsin and that the bleaching of this into retinal and opsin results in a cascade of events that allows an action potential to be initiated along the optic nerve. Time is taken to go through the events that occur in the dark and then the students are challenged to use this as a guide when explaining how the events differ in the light. Key terms like depolarisation and hyperpolarisation, that were met earlier in topic 8, are used to explain the changes in membrane potential and the resulting effect on the connection with the bipolar and ganglion cells is then described.

This fully-resourced lesson challenges the students to use fully labelled genetic diagrams to interpret the results of monohybrid and dihybrid crosses as detailed in topic 7.1 (Inheritance) of the AQA A-level Biology specification. Step-by-step guides are used to demonstrate how diagrams for the inheritance of one and two genes should be constructed and a focus is given to the areas where students commonly make mistakes, such as in writing out the gametes. The main task of each section of the lesson provides an opportunity for the students to apply their understanding by calculating phenotypic ratios. All of the questions have fully-explained mark schemes and students can assess their progress and address any misconceptions immediately. Key genetic terminology is used throughout the lesson and mirrors that used in actual exam questions.

This lesson describes the uses and implications of pre-implantation genetic diagnosis, amniocentesis and chorionic villus sampling. The lesson PowerPoint and accompanying worksheets have been primarily designed to cover point 2.15 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification but regular links are made to the earlier content of topics 1 & 2, and their knowledge of topics including the heart and circulation, monohybrid inheritance and cystic fibrosis are tested. The lesson begins by challenging them to use this prior knowledge of topic 2 to identify the letters in the abbreviations PGD and CVS. The involvement of IVF to obtain the embryos (or oocytes) is then discussed and a series of exam-style questions are used to get them to understand how this method screens embryos prior to implantation, so that those identified as having genetic diseases or being carriers are not inserted into the female’s uterus. Mark schemes for all of the questions included in this lesson are embedded into the PowerPoint so students can constantly assess their progress. Moving forwards, Down syndrome (trisomy 21) is used as an example of a chromosomal abnormality that can be tested for using CVS or amniocentesis. Time is taken to describe the key details of both of these procedures so students have a clear understanding of the implications and the invasiveness to the female being tested. The link between amniocentesis and an increased risk of miscarriage is considered and the results of a 2006 study are used to challenge them on their data skills.

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 meaning of biodiversity, explains how it relates to a range of habitats, and describes how to calculate an index of diversity. The PowerPoint and accompanying worksheets are part of the first in a series of 2 lessons that have been designed to cover the content of topic 4.6 of the AQA A-level Biology specification. The second lesson describes the balance between conservation and farming. A quiz competition called BIOLOGICAL TERMINOLOGY SNAP runs over the course of the lesson and this will engage the students whilst challenging them to recognise species, population, biodiversity, community and natural selection from their respective definitions. Once biodiversity as the variety of living organisms in a habitat is revealed, the students will learn that this can relate to a range of habitats, from those in the local area to the Earth. When considering the biodiversity of a local habitat, the need for sampling is discussed and some key details are provided to initially prepare the students for these lessons in topic 7. Moving forwards, the students will learn that it is possible to measure biodiversity within a habitat, within a species and within different habitats so that they can be compared. Species richness as a measure of the number of different species in a community is met and a biological example in the rainforests of Madagascar is used to increase its relevance. The students are introduced to an unfamiliar formula that calculates the heterozygosity index and are challenged to apply their knowledge to this situation, as well as linking a low H value to natural selection. The rest of the lesson focuses on the index of diversity and a 3-step guide is used to walk students through each part of the calculation. This is done in combination with a worked example to allow students to visualise how the formula should be applied to actual figures. Using the method, they will then calculate a value of d for a comparable habitat to allow the two values to be considered and the significance of a higher value is explained. All of the exam-style questions have mark schemes embedded in the PowerPoint to allow students to continuously assess their progress and understanding.

This engaging lesson looks at the structure of the quaternary protein, haemoglobin, and describes its role with red blood cells in the transport of oxygen. The PowerPoint has been designed to cover the first part of point 3.4.1 of the AQA A-level Biology specification and explains how the cooperative nature of binding results in a loading of each molecule with 4 oxygen molecules and describes how it is unloaded at the respiring cells too. The lesson begins with a version of the quiz show Pointless to introduce haemotology as the study of the blood conditions. Students are told that haemoglobin has a quaternary structure and are challenged to use their prior knowledge of biological molecules to determine what this means for the protein. They will learn that each of the 4 polypeptide chains contains a haem group with an iron ion attached and that it is this group which has a high affinity for oxygen. Time is taken to discuss how this protein must be able to load (and unload) oxygen as well as transport the molecules to the respiring tissues. Students will plot the oxyhaemoglobin dissociation curve and the S-shaped curve is used to encourage discussions about the ease with which haemoglobin loads each molecule. Students will learn that a conformational change upon binding of the first oxygen leads to it being easier to bind future oxygens and that this is known as cooperative binding. This lesson has been written to tie in with the other uploaded lesson on the Bohr effect.

An engaging lesson presentation (48 slides) and associated worksheets that uses a combination of exam questions, quick tasks and quiz competitions to help the students to assess their understanding of the topics found within unit P4 (Atomic structure) of the AQA GCSE Combined Science specification (specification point P6.4). The topics that are tested within the lesson include: The structure of an atom Isotopes Radioactive decay and nuclear radiation Nuclear equations Half-lives Students will be engaged through the numerous activities including quiz rounds like “It’s as easy as ABG” and “ALPHA or BETA” whilst crucially being able to recognise those areas which need further attention