This lesson explains how to calculate the mitotic index and then explores what a high value may indicate about the tissue that was sampled. The PowerPoint and accompanying resources are part of the 2nd lesson in a series of 3 which have been planned to cover the content of point 2.2 of the AQA A-level biology specification. As shown in the cover image, the lesson begins with a bit of fun, as the students are challenged to use three clues to identify three uses of the term index in biology. They’ll learn that the index of diversity is covered in a topic 4 lesson and that this lesson focuses on the mitotic index. The students are challenged on their knowledge of the mitotic cell cycle throughout the lesson and one of these questions is used to introduce the meaning of the index and the formula. A series of exam-style questions challenge them to apply their understanding, and the answers are embedded into the PowerPoint to enable the students to assess their progress. Moving forwards, the different meanings of high values are considered, including growing and repairing tissues, and then to explain how an elevated mitotic index can indicate that cell division has become uncontrolled. This prepares students for the next lesson where tumour formation and cancer will be covered.

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

This fully-resourced lesson explores the inheritance of sex-linked diseases in humans and then challenges the students to apply their knowledge to examples in other animals. The detailed PowerPoint and associated differentiated resources have been designed to cover the part of point 7.1 of the AQA A-level specification which states that students should be able to use fully-labelled genetic diagrams to predict the results of crosses involving sex-linkage. 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. In terms of humans, the lesson focuses on haemophilia and red-green colour blindness and a step-by-step guide is used to demonstrate how these specific genetic diagrams should be constructed and how the phenotypes should then be interpreted. The final tasks of the lesson challenge the students to carry out a dihybrid cross that involves a sex-linked disease and an autosomal disease before applying their knowledge to a question about chickens and how the rate of feather production in chicks can be used to determine gender. All of the tasks are differentiated so that students of differing abilities can access the work and all exam questions have fully-explained, visual markschemes to allow them to assess their progress and address any misconceptions

This lesson describes how genetic diversity within, or between species, can be investigated by comparison of characteristics or biological molecules. The PowerPoint and accompanying worksheets are primarily designed to cover the content of point 4.7 of the AQA A-level Biology specification but as this is the last lesson in the topic, it has also been planned to contain a range of questions, tasks and quiz rounds that will challenge the students on their knowledge and understanding of topic 4. Over the course of the lesson, the students will discover that comparisons of measurable or observable characteristics, DNA and mRNA sequences and the primary structure of common proteins can all be used to investigate diversity. Links are continually made to prior learning, such as the existence of convergent evolution as evidence of the need to compare biological molecules as opposed to the simple comparison of phenotypes. The issues associated with a limited genetic diversity are discussed and the interesting biological example of the congenital dysfunctions consistently found in the Sumatran tigers in captivity in Australia and New Zealand is used to demonstrate the problems of a small gene pool. Moving forwards, the study of the 16S ribosomal RNA gene by Carl Woese is introduced and students will learn that this led to the adoption of the three-domain system in 1990. The final part of the lesson describes how the primary structure of proteins like cytochrome c that is involved in respiration and is therefore found in most living organisms can be compared and challenges the students to demonstrate their understanding of protein synthesis when considering the differences between humans and rhesus monkeys.

This detailed lesson describes the structure and properties of the cell membrane, focusing on the phospholipid bilayer and membrane proteins. Fully resourced, the PowerPoint and accompanying worksheets have been designed to cover the first part of point 2.3 of the AQA A-level Biology specification and clear links are made to Singer and Nicholson’s fluid mosaic model 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 topic 1 and so 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 is a fully-resourced lesson that covers the details of specification point 5.1.2 (e) of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply an understanding of the effects of kidney failure and its potential treatments. This lesson consists of an engaging PowerPoint (55 slides) and associated differentiated worksheets that look at 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 is designed for A-level students who are studying the OCR A-level Biology specification and ties in nicely with the other uploaded lessons on this organ which include the structure and function of the nephron, ultrafiltration, selective reabsorption and osmoregulation.

This detailed lesson has been planned to cover the 1st part of specification point 6.4.3 of the AQA A-level Biology specification which states that students should be able to describe the detailed structure of the nephron and understand its role in ultrafiltration, selective reabsorption and osmoregulation. The lesson was designed at the same time as the other lessons in this topic on ultrafiltration, selective reabsorption and osmoregulation so that a common theme runs throughout and students can build up their knowledge gradually in order to develop a deep understanding of this organ. Students will come to recognise the renal cortex and renal medulla as the two regions of the kidney and learn the parts of the nephron which are found in each of these regions. Time is taken to look at the vascular supply of this organ and specifically to explain how the renal artery divides into the afferent arterioles which carry blood towards the glomerulus and the efferent arterioles which carry the blood away. The main task of the lesson challenges the students to relate structure to function. Having been introduced to the names of each of the parts of the nephron, they have to use the details of the structures found at these parts to match the function. For example, they have to make the connection between the microvilli in the PCT as a sign that this part is involved in selective reabsorption. This lesson has been designed for students studying on the AQA A-level Biology course

This fully-resourced lesson focuses on the events of meiosis which specifically contribute to genetic variation. The detailed PowerPoint and accompanying resources have been designed to cover the 4th and final part of point 4.3 of the AQA A-level Biology specification which states that students should be able to describe how meiosis produces daughter cells that are genetically different from each other. In order to understand how the events of meiosis like crossing over and random assortment and independent segregation can lead to variation, students need to be clear in their understanding that DNA replication in interphase results in homologous chromosomes as pairs of sister chromatids. Therefore the beginning of the lesson focuses on the chromosomes in the parent cell and this first part of the cycle and students will be introduced to non-sister chromatids and the fact that they may contain different alleles which is important for the exchange that occurs during crossing over. Time is taken to go through this event in prophase I in a step by step guide so that the students can recognise that the result can be new combinations of alleles that were not present in the parent cell. Moving forwards, the lesson explores how the independent segregation of chromosomes and chromatids during anaphase I and II results in genetically different gametes. The final part of the lesson looks at the use of a mathematical expression to calculate the possible combinations of alleles in gametes as well as in a zygote following the random fertilisation of haploid gametes. Understanding and prior knowledge checks are interspersed throughout the lesson as well as a series of exam questions which challenge the students to apply their knowledge to potentially unfamiliar situations. Due to the detail of this lesson, it is estimated that this will take about 2 hours of A-level teaching time to deliver

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 lesson focuses on the key terms associated with ecosystems and describes how populations are affected by a range of factors. The PowerPoint and accompanying resources are part of the 1st lesson in a series of 4 lessons that cover the details of point 7.4 of the AQA A-level Biology specification As shown in the cover image, a modified version of the quiz competition BLOCKBUSTERS runs throughout the lesson and this introduces new terms as well as challenging students to recall key terms that were encountered in previous topics. These include population, ecosystems, competition, niche, abiotic factors and carrying capacity. Each time a term is met, time is taken to describe its meaning and to explain its relevance and context in this topic of populations in ecosystems. Exam-style questions are also used to challenge the students to apply their understanding and displayed mark schemes allow them to assess their progress. Prior knowledge checks interspersed within the lesson which check on topics such as the nitrogen cycle, adaptations and the biological classification of a species