This lesson guides students through the use of the 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 task worksheets that have been designed to cover the part of point 7.1 of the AQA A-level Biology specification which states that students should be able to use the test to compare the goodness of fit between the observed phenotypic ratios and expected ratios. The lesson has been written to include a step-by-step guide that demonstrates how to carry out the test in small sections. 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 is the final lesson of topic 7.1 (inheritance) and links are made throughout the lesson to earlier parts of this topic such as dihybrid inheritance as well as to earlier topics such as meiosis.

This clear and concise lesson looks at the phenomenon known as the Bohr effect and describes and explains how an increased carbon dioxide concentration effects the dissociation of oxyhaemoglobin. The PowerPoint has been designed to cover the second part of point 3.4.1 of the AQA A-level Biology specification and continually ties in with the previous lesson on the role of haemoglobin. The lesson begins with a terminology check to ensure that the students can use the terms affinity, oxyhaemoglobin and dissociation. In line with this, they are challenged to draw the oxyhaemoglobin dissociation curve and are reminded that this shows how oxygen associates with haemoglobin but how it dissociates at low partial pressures. Moving forwards, a quick quiz is used to introduce Christian Bohr and the students are given some initial details of his described effect. This leads into a series of discussions where the outcome is the understanding that an increased concentration of carbon dioxide decreases the affinity of haemoglobin for oxygen. The students will learn that this reduction in affinity is a result of a decrease in the pH of the cell cytoplasm which alters the tertiary structure of the haemoglobin. Opportunities are taken at this point to challenge students on their prior knowledge of protein structures as well as the bonds in the tertiary structure. The lesson finishes with a series of questions where the understanding and application skills are tested as students have to explain the benefit of the Bohr effect for an exercising individual.

A highly engaging lesson presentation (74 slides) and accompanying worksheets that uses exam questions (with explained answers), quick tasks and quiz competitions to allow students to assess their understanding of the topic of Biological molecules (Topic 3.1). Students will have fun whilst recognising those areas of the specification which need further attention.

This lesson describes how epigenetic changes like DNA methylation and histone modification can modify the activation of certain genes. The PowerPoint and accompanying resources have been planned to cover points 3.14 ii & iii of the Pearson Edexcel A-level biology (Salters-Nuffield) specification. The lesson begins by introducing the prefix epi- as meaning on or above in Greek to allow students to recognise that epigenetics refers to changes in gene function due to factors beyond the genetic code. Moving forwards, they will learn that DNA methylation involves the attachment of a methyl group to cytosine and will come to understand how this inhibits transcription. They are challenged to recognise the pathogenesis of atherosclerosis through a variety of tasks before reading through a source detailing the results of a study between this cardiovascular condition and DNA methylation. The remainder of the lesson considers how the acetylation of histone proteins affects the expression of genes. Understanding and prior knowledge checks are embedded throughout the lesson (along with the answers) to allow the students to assess their progress on this topic and to encourage them to make links to the content of topics 1 - 2.

This fully-resourced lesson describes the process of anaerobic respiration in eukaryotes and explains how pyruvate can be converted to lactate or ethanol using the hydrogen atoms released from reduced NAD and that the reoxidation of this coenzyme allows glycolysis to continue. The engaging and detailed PowerPoint and accompanying differentiated resources have been designed to cover the first part of point 5.2.2 (i) of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply their knowledge and understanding of anaerobic respiration in mammals and yeast. The lesson begins with a focus on the coenzyme, NAD, and students are challenged to recall details of its role in the oxidation of triose phosphate. Students will recall that oxidative phosphorylation in aerobic respiration allows these coenzymes to be reoxidised and therefore recognise that another metabolic pathway has to operate when there is no oxygen available. Time is taken to go through the details of the lactate and ethanol fermentation pathways and students are encouraged to discuss the conversions before applying their knowledge to complete diagrams and passages about the pathways. Understanding checks in a range of forms are used to enable the students to assess their progress whilst prior knowledge checks allow them to recognise the links to earlier topics. This lesson has been written to tie in with the other uploaded lessons on glycolysis and the stages of aerobic respiration

This fully-resourced lesson describes the meaning of directional and stabilising selection and uses real-life examples to develop student understanding. The PowerPoint and accompanying resources are part of the 3rd lesson in a series of 4 that have been designed to cover the details of topic 4.4 (genetic diversity and adaptation) of the AQA A-level biology specification. As stated in the specification, antibiotic resistance is used as the key example to explain directional selection whereas human baby birth weight explains stabilising selection. The lesson is filled with current understanding checks so any misunderstandings can be immediately addressed, and also prior knowledge checks, where students are expected to recall key details from lessons in this topic so they can make important links. The lesson concludes with a short quiz called “SELECT that word” (shown on the cover image) where students have to identify the types of selection from clues to reveal a key biological word.

This detailed and engaging lesson describes the different ecological techniques used to assess the abundance and distribution of organisms in a habitat. In line with point 10.1 (iv) of the Edexcel A-level biology B specification, the following techniques are included in the PowerPoint and accompanying resources: quadrats (of differing areas) transects ACFOR scale percentage cover The mathematical element of the course is challenged in the early stages of this lesson, when the students have to estimate the populations of different plant species using data obtained with a quadrat. Understanding checks are used throughout the lesson to allow the students to assess their progress against the current topic and they are encouraged to consider the advantages and disadvantages of each technique.

This fully-resourced lesson describes the stages of succession from colonisation to climax community. The PowerPoint and accompanying worksheets have been designed to cover the content of point 5.4 of the Edexcel A-level Biology A specification. As you can see from the cover image, this lesson uses a step-by-step method to guide the students through each stage of the process of succession, explaining each of the gradual, progressive changes that occur in a community over time. At each stage, time is taken to consider the organisms involved. There is a focus on lichens as examples of pioneer species and students will understand how colonisation by these organisms is critical to provide organic matter and to turn the bare ground into soil so it is habitable by other species. The island of Surtsey in Iceland is used as real-world example and shows how different parts of an area can be at different stages of succession. Understanding and prior knowledge checks are embedded into the PowerPoint (along with the answers) to allow students to assess their progress against the current topic and to encourage them to make links to previously-covered work.

This fully-resourced lesson describes the behaviour of chromosomes during interphase, mitosis and cytokinesis in the cell cycle. The detailed PowerPoint and accompanying resources have been designed to cover the first half of point 2.2 as detailed in the AQA A-level Biology specification whereas uncontrolled cell division and cancer and binary fission are covered in upcoming lessons. Depending upon the exam board taken at GCSE, the knowledge and understanding of mitosis and the cell cycle 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 and to address existing errors, key points are emphasised throughout. The cell cycle is introduced at the start of the lesson and the quantity of DNA inside the parent cell is described as diploid and as 2n. A quiz competition has been written into the lesson and this runs throughout, challenging the students to identify the quantity of DNA in the cell (in terms of n) at different points of the cycle. Moving forwards, the first real focus is interphase and the importance of DNA replication is explained so that students can initially recognise that there are pairs of identical sister chromatids and then can understand how they are separated later in the cycle. The main part of the lesson focuses on prophase, metaphase, anaphase and telophase and describes how the chromosomes behave in these stages. Centrioles were not covered in the topic 2.1 lessons on cell structures so a quick task will introduce them to these organelles who are responsible for the production of the spindle apparatus, Students will understand how the cytoplasmic division that occurs in cytokinesis results in the production of genetically identical daughter cells. This leads into a series of understanding and application questions where students have to identify the various roles of mitosis in living organisms as well as tackling a Maths in a Biology context question. The lesson concludes with a final round of MITOSIS SNAP where they only shout out this word when a match is seen between the name of a phase, an event and a picture.

An engaging lesson presentation (41 slides) and accompanying worksheet that looks at the different causes of variation and the different types of variation. The lesson begins by challenging the students to pick out a set of siblings from a series of pictures and then getting them to explain scientifically why they made the decision that they did. Moving forwards, students will recognise that one cause of variation is genes. Students are shown a pair of identical twins and asked to explain why they look different despite their identical genes so that they can understand that the environment also affects variation. Students will also meet discontinuous and continuous variation and will understand how this data should be represented. There are progress checks throughout the lesson to allow the students to assess their understanding. This lesson has been designed for KS3 and GCSE students.

This lesson describes how the role of carrier of proteins and ATP in active transport and the co-transport of sodium ions and glucose in the ileum. The PowerPoint and accompanying resources are part of the final lesson in a series of 3 that have been designed to cover the details of point 2.3 of the AQA A-level Biology specification and also includes descriptions of endocytosis and exocytosis The start of the lesson focuses on the structure of this energy currency and challenges the students prior knowledge as they covered ATP in topic 1.6. As a result, they will recall that this molecule consists of adenine, ribose and three phosphate groups and that in order to release the stored energy, ATP must be hydrolysed. Time is taken to emphasise the key point that the hydrolysis of ATP can be coupled to energy-requiring reactions and this leads into a series of exam-style questions where students are challenged on their knowledge of simple and facilitated diffusion to recognise that ATP is needed for active transport. These questions also challenge them to compare active transport against the forms of passive transport and to use data from a bar chart to support this form of transport. In answering these questions they will discover that carrier proteins are specific to certain molecules and time is taken to look at the exact mechanism of these transmembrane proteins. A quick quiz round introduces endocytosis and the students will see how vesicles are involved along with the energy source of ATP to move large substances in or out of the cell. The students are then shown how exocytosis is involved in a synapse and in the release of ADH from the pituitary gland during osmoregulation which they will cover in later topics. The final part of the lesson describes the movement of sodium ions and glucose from the ileum to the epithelial cells to the blood using a range of proteins which includes cotransporter proteins and students will learn that similar mechanisms are seen in the phloem and in the proximal convoluted tubule.

This clear and concise lesson explains how the inheritance of two or more genes that have loci on the same autosome demonstrates autosomal linkage. The engaging PowerPoint and associated resource have been designed to cover the part of point 6.1.2 (b[ii]) of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply their knowledge and understanding of the use of phenotypic ratios to identify autosomal linkage. This is a topic which can cause confusion for students so time was taken in the design to split the concept into small chunks. There is a clear focus on how the number of original phenotypes and recombinants can be used 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 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. The main task of the lesson acts as an understanding check where students are challenged to analyse a set of results involving the inheritance of the ABO blood group gene and the nail-patella syndrome gene to determine whether they have loci on the same chromosome and if so, how close their loci would appear to be. This lesson has been written to tie in with the other lessons from module 6.1.2 (Patterns of Inheritance)

This clear and concise lesson explains how the inheritance of two or more genes that have loci on the same autosome demonstrates autosomal linkage. The engaging PowerPoint and associated resource have been designed to cover the part of point 7.1 of the AQA A-level Biology specification which states that students should be able to use fully-labelled genetic diagrams to interpret the results of crosses involving autosomal linkage. This is a topic which can cause confusion for students so time was taken in the design to split the concept into small chunks. There is a clear focus on how the number of original phenotypes and recombinants can be used 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 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. The main task of the lesson acts as an understanding check where students are challenged to analyse a set of results involving the inheritance of the ABO blood group gene and the nail-patella syndrome gene to determine whether they have loci on the same chromosome and if so, how close their loci would appear to be. This lesson has been written to tie in with the other 6 lessons from topic 7.1 (Inheritance) and these have also been uploaded

This engaging and fully-resourced lesson looks at how genetic drift can arise after a genetic bottleneck or as a result of the Founder effect. The detailed PowerPoint and accompanying resources have been designed to cover the fourth part of point 7.3 of the AQA A-level Biology specification which states that students should be able to explain the importance of genetic drift in causing changes in allele frequency in small populations A wide range of examples are used to show the students how a population that descends from a small number of parents will have a reduction in genetic variation and a change in the frequency of existing alleles. Students are encouraged to discuss new information to consider key points and understanding checks in a range of forms are used to enable them to check their progress and address any misconceptions. Students are provided with three articles on Huntington’s disease in South Africa, the Caribbean lizards and the plains bison to understand how either a sharp reduction in numbers of a new population beginning from a handful of individuals results in a small gene pool. Links to related topics are made throughout the lesson to ensure that a deep understanding is gained.

This fully-resourced lesson looks at the coordination and control of heart rate by the cardiovascular centre in the medulla oblongata. The engaging and detailed PowerPoint and accompanying resources have been designed to cover the second part of point 6.1.3 of the AQA A-level Biology specification which states that students should know the roles and locations of the sensory receptors and the roles of the autonomic nervous system and effectors in the control of heart rate. This lesson begins with a prior knowledge check where students have to identify and correct any errors in a passage about the conduction system of the heart. This allows the SAN to be recalled as this structure play an important role as the effector in this control system. Moving forwards, the three key parts of a control system are recalled as the next part of the lesson will specifically look at the range of sensory receptors, the coordination centre and the effector. Students are introduced to chemoreceptors and baroreceptors and time is taken to ensure that the understanding of the stimuli detected by these receptors is complete and that they recognise the result is the conduction of an impulse along a neurone to the brain. A quick quiz is used to introduce the medulla oblongata as the location of the cardiovascular centre. The communication between this centre and the SAN through the autonomic nervous system can be poorly understood so detailed explanations are provided and the sympathetic and parasympathetic divisions compared. The final task challenges the students to demonstrate and apply their understanding by writing a detailed description of the control and this task has been differentiated three ways to allow differing abilities to access the work This lesson has been written to tie in with the previous lesson on the conducting system of the heart which is also detailed in specification point 6.1.3

This engaging and fully-resourced lesson looks at the effects of stabilising, directional and disruptive selection as the three main types of selection. The PowerPoint and accompanying resources have been designed to cover the 3rd part of point 7.3 of the AQA A-level Biology specification which states that students should be able to identify each type of selection by its effect on different phenotypes. The lesson begins with an introduction to the mark, release, recapture method to calculate numbers of rabbits with different coloured fur in a particular habitat. This method is covered later in topic 7 so this section of the lesson is designed purely to generate changes in numbers of the organisms. Sketch graphs are then constructed to show the changes in the population size in this example. A quick quiz competition is used to engage the students whilst introducing the names of the three main types of selection before a class discussion point encourages the students to recognise which specific type of selection is represented by the rabbits. Key terminology including intermediate and extreme phenotypes and selection pressure are used to emphasise their importance during explanations. A change in the environment of the habitat and a change in the numbers of the rabbits introduces directional selection before students will be given time to discuss and to predict the shape of the sketch graph for disruptive selection. Students are challenged to apply their knowledge in the final task of the lesson by choosing the correct type of selection when presented with details of a population and answer related questions.

This is an engaging and fully-resourced revision lesson which uses a range of exam questions, understanding checks, quiz tasks and quiz competitions to enable students to assess their understanding of the content within topic 1 (Key concepts in Biology) of the Edexcel GCSE Biology 9-1 specification. The specification points that are covered in this revision lesson include: Explain how the sub-cellular structures of eukaryotic and prokaryotic cells are related to their functions Describe how specialised cells are adapted to their function Know that changes in microscope technology, including electron microscopy, have enabled us to see cell structures and organelles with more clarity and detail than in the past Demonstrate an understanding of the relationship between quantitative units in relation to cells Explain how substances are transported into and out of cells, including by diffusion, osmosis and active transport Core Practical: Investigate osmosis in potatoes Calculate percentage gain and loss of mass in osmosis The students will thoroughly enjoy the range of activities, which include quiz competitions such as “CELL, CELL, CELL” where they have to compete to quickly identify specialised cells from their descriptions whilst crucially being able to recognise the areas of this topic which need their further attention. This lesson can be used as revision resource at the end of the topic or in the lead up to mocks or the actual GCSE exams.

This lesson has been written to cover the part of specification point 6.4.3 of the AQA A-level Biology specification which states that students should be able to describe how water and glucose are reabsorbed in the proximal convoluted tubule. It has specifically been designed to build on the knowledge gained in the previous lessons on the structure of the nephron and ultrafiltration. 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 PCT 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 lesson has been designed for students studying on the AQA-A level Biology course and ties in nicely with the other lessons from 6.4.3 as well as the other uploaded lessons from topic 6

This lesson describes and explains how production is affected by a range of farming practices designed to increase the efficiency of energy transfer. The PowerPoint and accompanying resources are part of the third lesson in a series of 3 which have been designed to cover the detail included in specification point 5.3 of the AQA A-level Biology specification. Over the course of the lesson, a range of tasks which include exam-style questions with displayed mark schemes, guided discussion periods and quick quiz competitions will introduce and consider the following farming practices: raising herbivores to reduce the number of trophic levels in a food chain intensely rearing animals to reduce respiratory losses in human food chains the use of fungicides, insecticides and herbicides the addition of artificial fertilisers The ethical issues raised by these practices are also considered and alternative methods discussed such as the addition of natural predators and the use of organic fertilisers like manure As this is the last lesson in topic 5.3, it has been specifically planned to challenge the students on their knowledge of the previous two lessons and this includes a series of questions linking farming practice to the formula to calculate net production

This fully-resourced lesson describes how antibodies are used in the enzyme-linked immunosorbent assay (ELISA) test. The PowerPoint and accompanying resources are part of the last lesson in a series of 7 which have been designed to cover the details within point 2.4 of the AQA A-level specification. As the last lesson in this sub-topic, prior knowledge checks are included throughout the lesson which challenge the students on their knowledge of antibodies, immunity and protein structure. The lesson begins by challenging the students to use the details of a poster to recognise that individuals who have recovered from COVID-19 could donate plasma and the antibodies be infused into newly infected individuals. They are then expected to answer a series of exam-style questions where they have to describe the structure of these specific antibodies, recognise this as artificial, passive immunity and describe the potential problems should the virus mutate and the shape of its antigens change. This leads into the introduction of the use of antibodies in other ways, namely the ELISA test. The methodology of this test has been divided into four key steps which students will consider one at a time and then answer further questions about key details such as the immobilisation of the antigen and the removal of proteins and antibodies that have not bound by the washing with the detergent after each step. The lesson focuses on the use of this test for medical diagnosis but other uses such as plant pathology and the detection of allergens is briefly introduced at the end of the lesson.