This lesson describes how Fick’s law of diffusion is governed by the three main properties of gas exchange surfaces in living organisms. The PowerPoint and accompanying worksheets have been designed to cover points 2.1 (i & ii) of the Edexcel International A-level Biology specification and there is a particular focus on the relationship between the size of an organism or structure and its surface to volume ratio. Adolf Fick is briefly introduced at the start of the lesson and the students will learn that his law of diffusion governs the diffusion of a gas across a membrane and is dependent on three properties. The students are likely to know that surface area is one of these properties but although they may have been introduced to the surface area to volume ratio at iGCSE, their understanding of its relevance tends to be mixed. Therefore, real life examples are included throughout the lesson that emphasise the importance of this ratio in order to increase the relevance. A lot of students worry about the maths calculations that are associated with this topic so a step by step guide is included at the start of the lesson to walk them through the calculation of the surface area, the volume and then the ratio. Through worked examples and understanding checks, SA/V ratios are calculated for cubes of increasing side length and living organisms of different size. These comparative values will enable the students to conclude that the larger the organism or structure, the lower the surface area to volume ratio. A differentiated task is then used to challenge the students to explain the relationship between the ratio and the metabolic demands of an organism and this leads into the next part of the lesson, where the adaptations of a human to increase the ratio at the gas exchange surface is covered. The students will calculate the SA/V ratio of a human alveolus (using the surface area and volume formulae for a sphere) and will see the significant increase that results from the folding of the membranes. The remainder of the lesson introduces concentration difference and thickness of membrane as the other two properties in Fick’s law of diffusion and students are reminded that the maintenance of a steep concentration gradient and a reduction in the diffusion distance are critical for this transport mechanism. This lesson has been specifically planned to prepare students for the next lesson which describes how the structure of the mammalian lung is adapted for rapid gas exchange (specification point 2.1 [iii])

This lesson describes the principles of in situ conservation and considers the benefits as well as the issues that surround this method. The PowerPoint and accompanying resources are part of the first lesson in a series of 2 which have been designed to cover the content of point 3.3 (iii) of the Edexcel A-level Biology B specification. Hours of research have gone into the planning of this lesson to source interesting examples to increase the relevance of the biological content, and these include the Lizard National Nature Reserve in Cornwall, the Lake Télé Community reserve in the Republic of Congo and the marine conservation zone in the waters surrounding Tristan da Cunha. Students will learn how this form of active management conserves habitats and species in their natural environment, with the aim of minimising human impact whilst maintaining biodiversity. The main issues surrounding this method are discussed, including the fact that the impact of this conservation may not be significant if the population has lost much of its genetic diversity and that despite the management, the conditions that caused the species to become endangered may still be present. A number of quick quiz competitions are interspersed throughout the lesson to introduce key terms and values in a fun and memorable way and one of these challenges them to use their knowledge of famous scientists to reveal the surname, Fossey. Dian Fossey was an American conservationist and her years of study of the mountain gorillas is briefly discussed along with the final issue that wildlife reserves can draw poachers and tourists to the area, potentially disturbing the natural habitat.

This lesson describes the ethical and economic reasons for the maintenance of biodiversity. The engaging PowerPoint and accompanying worksheets are filled with real-life biological examples and have been designed to cover point 3.3 (ii) of the Edexcel A-level Biology B specification. Many hours of research have gone into the planning of the lesson so that interesting examples are included to increase the relevance of the multitude of reasons to maintain biodiversity. These include the gray wolves and beavers of Yellowstone National Park and the Za boabab in the Madagascar rainforests as examples of keystone species. Students will learn that these species have a disproportionate effect on their environment relative to their abundance and exam-style questions and guided discussion periods are used to challenge them to explain their effect on other species in the habitat. The latest A-level Biology exams have a heavy mathematical content and this is reflected in this lesson as students are challenged to complete a range of calculations to manipulate data to support their biological-based answers. All of the exam questions that are included throughout the lesson have mark schemes embedded into the PowerPoint to allow the students to assess their progress. Moving fowards, the economic ans aesthetic reasons to maintain biodiversity are considered, and there is a focus on the soil depletion that occurs when a continuous monoculture is used. The 1 Billion tree scheme that began in New Zealand in 2018 is introduced and the reasons that some groups of people are objecting to what they consider to be a pine monoculture are discussed. Students will recognise that the clear felling of the trees dramatically changes the landscape and that the increased runoff that results can have catastrophic affects for both aquatic life and for humans with floods. A number of quiz competitions are included in the lesson to introduce key terms in a fun and memorable way and some of the worksheets have been differentiated to allow students of differing abilities to access the work

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 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 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

This fully-resourced lesson describes how mutations, the events of meiosis and random fertilisation result in genetic variation. The engaging PowerPoint and accompanying resources have been primarily designed to cover points 8.1 (i) & (ii) of the Edexcel A-level Biology B specification but also includes activities to challenge the students on previous concepts in topics 1 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 although this lesson only focuses on the genetic aspect. 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. The final section of the lesson focuses on the production of haploid gametes by meiosis and discusses how the random fertilisation of these gametes during sexual reproduction further increases variation.

This detailed lesson describes the fluid mosaic model of membrane structure and also describes the roles of its components. The detailed and engaging PowerPoint and accompanying worksheets have been designed to cover specification point 2.1.5 (b) of the OCR A-level Biology A specification and clear links are made to related topics such as the binding of peptide hormones 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 module 2.1.2 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 an upcoming topic so that students can understand how hormones or drugs will bind to target cells in this way. 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 fully-resourced lesson guides students through the use of the Hardy-Weinberg equation to monitor changes in allele frequencies in a population. The detailed PowerPoint and differentiated practice questions worksheets have been designed to cover point 8.3 (iv) of the Edexcel A-level Biology B specification The lesson begins with a focus on the equation to ensure that the students understand the meaning of each of the terms. The recessive condition, cystic fibrosis, is used as an example so that students can start to apply their knowledge and assess whether they understand which genotypes go with which term. Moving forwards, a step-by-step guide is used to show students how to answer a question. Tips are given during the guide so that common misconceptions and mistakes are addressed immediately. The rest of the lesson gives students the opportunity to apply their knowledge to a set of 3 questions, which have been differentiated so that all abilities are able to access the work and be challenged

This fully-resourced lesson describes how natural selection leads to behavioural, anatomical and physiological adaptations. The PowerPoint and accompanying resources have been designed to cover specification points 4.3 & 4.4 of the Pearson Edexcel A-level Biology A 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 evolution through natural selection. The main task of the lesson challenges the students to form a description that explains how this strain of bacteria developed resistance to methicillin to enable them to see the principles of natural selection. This can then be used when describing how the anatomy of the modern-day giraffe has evolved over time. The concept of convergent evolution is introduced and links are made to the need for modern classification techniques as this is covered later in topic 4. Moving forwards, students will understand how natural selection leads to adaptations and a quick quiz competition 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. Due to the extensiveness of this lesson and the detail contained within the resources, it is estimated that it will take in excess of 2 hours of allocated A-level teaching time to deliver this lesson.

This fully-resourced lesson describes the relationship between the structure, properties and functions of triglycerides in living organisms. The engaging PowerPoint and accompanying worksheets have been designed to cover the first part of point (f) as detailed in AS unit 1, topic 1 of the WJEC A-level Biology specification and links are also made to related future topics such as the importance of the myelin sheath for the conduction of an electrical impulse which is covered in A2. The lesson begins with a focus on the basic structure and roles of lipids, including the elements that are found in this biological molecule and some of the places in living organisms where they are found. Moving forwards, the students are challenged to recall the structure of the carbohydrates from earlier in topic 1 so that the structure of a triglyceride can be introduced. Students will learn that this macromolecule is formed from one glycerol molecule and three fatty acids and have to use their understanding of condensation reactions to draw the final structure. Time is taken to look at the difference in structure and properties of saturated and unsaturated fatty acids and students will be able to identify one from the other when presented with a molecular formula. The final part of the lesson explores how the various properties of a triglyceride mean that it has numerous roles in organisms including that of an energy store and source and as an insulator of heat and electricity.

This lesson ensures that students know the meaning of key ecological terms and explains how biotic and abiotic factors control the distribution of organisms. The engaging PowerPoint and accompanying resources have been designed to cover points 5.1, 5.2 and 5.3 of the Pearson Edexcel A-level Biology A (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, 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 the modes of action of the T and B lymphocytes in the immune response. The detailed PowerPoint and accompanying resources have been designed to cover point 2.4 of the CIE A-level Biology specification and the structure of antibodies and the roles of memory cells is also briefly introduced. Antigen presentation was introduced at the end of the previous lesson so the task at the start of this lesson challenges students to recognise the name of this process and then they have to spot the errors in the passage that describes the details of this event. This reminds them that contact between the APC and T lymphocytes is necessary to elicit a response which they will come to recognise as the cellular response. A series of quick quiz rounds reveals key terms in a memorable way and one that is introduced is helper T cells. Time is then taken to describe the importance of cell signalling for an effective response and students will learn how the release of chemicals by these cells activates other aspects of the response. The role of the killer T cells is also described before an exam-style question is used to check on their understanding at this point of the lesson. This leads into the section of the lesson that deals with the humoral response and students will understand how this involves the antibodies that are produced by the plasma cells that are the result of clonal selection and expansion. The remainder of the lesson focuses on the role of the antibodies and the attachment of phagocytes to opsonins.

A fully-resourced lesson that looks at the different sampling methods that can be used to estimate the populations of animals and plants in a habitat and to analyse how their distribution is affected, The lesson includes a detailed and engaging lesson presentation (56 slides) and differentiated worksheets so that students of different abilities are challenged and can access the work. The lesson begins by looking at the use of a quadrat to estimate the population of plants in a habitat. There is a focus on the mathematical calculations associated with the method and students are given hints and worked examples so that any common misconceptions are addressed. Moving forwards, students are introduced to the capture-mark-recapture technique to sample animals. The rest of the lesson looks at alternative pieces of apparatus, such as the sweep net, and discusses situations when these would be used. This lesson has been written for GCSE students (14 - 16 year olds in the UK) but is appropriate for both younger students who are learning about ecology and also for A-level students who need a recap on this topic.