Water is very important for living organisms because of its numerous properties and this lesson focuses on its role as a solvent in transport. The engaging and detailed PowerPoint and accompanying worksheet have been designed to cover point 1.1 of the Edexcel International A-level Biology specification and also explains the importance of the dipole nature for this role in transport. A mathematical theme runs throughout the lesson as students have to match the numbers calculated in the starter task to water statistics, such as the percentage of the volume of blood plasma that is water. This has been included to try to increase the relevance of each property so that it can be described in a biological context. Time is taken at the beginning of the lesson to describe the structure of water in terms of the covalent bonds between the oxygen and hydrogen atoms as well as the hydrogen bonds which form between molecules because of its polarity. Students will understand how water is a solvent which means that it is critical for transport in animals, a topic covered in the next few lessons but also for transport in plants as discussed in topic 4. The high heat capacity and latent heat of vaporisation of water is also discussed and explained through the examples of thermoregulation and the maintenance of a stable environment for aquatic animals. The final part of the lesson focuses on the involvement of water in condensation and hydrolysis reactions, two reactions which must be well understood for topic 1 and 2 and the formation and breakage of polysaccharides, lipids, polypeptides and polynucleotides.

Simple and facilitated diffusion are forms of passive transport and this lesson describes the factors that increase the rate of this movement across membranes. This fully-resourced lesson is the first in a series of two that have been designed to cover specification point 2.4 of the Pearson Edexcel A-level Biology A and the involvement of channel and carrier proteins is also described and discussed. In a number of previous lessons that covered specification points 2.1 and 2.2, students were provided with the details of gas exchange surfaces and the structure and properties of cell membranes. This lesson continually refers back to the content of these lessons so that links can be made between the movement across a cell membrane with the concentration gradient, the parts of the membrane involved and any features that may increase the rate at which the molecules move. A series of questions about the alveoli is used to demonstrate how a large surface area, a short diffusion distance and the maintenance of a steep concentration gradient will increase the rate of simple diffusion. One of two quick quiz rounds is then used to introduce temperature and size of molecule as two further factors that can affect simple diffusion. The remainder of the lesson focuses on facilitated diffusion and describes how transmembrane proteins are needed to move small, polar or large molecules from a high concentration to a lower concentration across a partially permeable membrane. The other lesson included in this series to cover specification point 2.4 describes active transport, endocytosis and exocytosis.

This fully-resourced lesson describes the use of vaccinations to protect individuals and populations and the differences between active and passive immunity. The engaging PowerPoint and accompanying resources have been designed to cover the fourth part of point 2.4 of the AQA A-level Biology specification and there is also a description and discussion on the concept of herd immunity. The previous lesson finished with a series of exam questions where students observed differences between the primary and secondary immune responses so the start of this lesson uses an imaginary game of TOP TRUMPS to challenge them on the depth of their understanding. This will act to remind them that a larger concentration of antibodies is produced in a quicker time in the secondary response. The importance of antibodies and the production of memory cells for the development of immunity is emphasised and this will be continually referenced as the lesson progresses. The students will learn that this response of the body to a pathogen that has entered the body through natural processes is natural active immunity. Moving forwards, time is taken to look at vaccinations as an example of artificial active immunity. Another series of questions focusing on the MMR vaccine will challenge the students to explain how the deliberate exposure to antigenic material activates the immune response and leads to the retention of memory cells. A quick quiz competition is used to introduce the variety of forms that the antigenic material can take along with examples of diseases that are vaccinated against using these methods. The eradication of smallpox is used to describe the concept of herd immunity and the students are given time to consider the scientific questions and concerns that arise when the use of this pathway is a possible option for a government. The remainder of the lesson looks at the different forms of passive immunity and describes the drawbacks in terms of the need for a full response if a pathogen is reencoutered.

This lesson describes the sequence of events that occur during the phagocytosis of pathogens and the subsequent destruction by lysozymes. The engaging and detailed PowerPoint and accompanying resources have been primarily designed to cover the second part of point 2.4 of the AQA A-level Biology specification but includes an introduction to antigen-presentation so that the students are prepared for upcoming lessons on the cellular and humoral responses. At the start of the lesson, the students are challenged to recall that cytosis is a suffix associated with transport mechanisms and this introduces phagocytosis as a form of endocytosis which takes in pathogens and foreign particles. This emphasis on key terminology runs throughout the course of the lesson and students are encouraged to consider how the start or end of a word can be used to determine meaning. The process of phagocytosis is then split into 5 key steps and time is taken to discuss the role of opsonins as well as the fusion of lysosomes and the release of lysozymes. A series of application questions are used to challenge the students on their ability to make links to related topics including an understanding of how the hydrolysis of the peptidoglycan wall of a bacteria results in lysis. Students will be able to distinguish between neutrophils and monocytes from a diagram and at this point, the role of macrophages and dendritic cells as antigen-presenting cells is described so that it can be used in the next lesson. The lesson concludes with a brief introduction to lymphocytes so that initial links between phagocytosis and the specific immune responses are made.

This lesson describes the movement across cell membranes by simple and facilitated diffusion and describes how the rate is increased. The PowerPoint and accompanying resources have been designed to cover the second part of specification point 2.3 of the AQA A-level Biology course and the limitations imposed by the phospholipid bilayer and the role of channel and carrier proteins are described in detail. The structure and properties of cell membranes was covered in the previous lesson so this one has been written to include continual references to the content of these lessons. This enables links to be made between the movement across a cell membrane with the concentration gradient, the parts of the membrane that are involved and any features that may increase the rate at which the molecules move. A series of questions about the alveoli are used to demonstrate how a large surface area, a short diffusion distance and the maintenance of a steep concentration gradient will increase the rate of simple diffusion. One of two quick quiz rounds is then used to introduce temperature and size of molecule as two further factors that can affect simple diffusion. The remainder of the lesson focuses on facilitated diffusion and describes how transmembrane proteins are needed to move small, polar or large molecules from a high concentration to a lower concentration across a partially permeable membrane.

This lesson describes and explains the processes of simple diffusion and facilitated diffusion. The PowerPoint and accompanying resources have been designed to cover the first part of specification point 4.2 (a) of the CIE International A-level Biology course and the factors that increase the rate of diffusion are covered along with the limitations imposed by the phospholipid bilayer and the role of channel and carrier proteins. The structure and properties of cell membranes was covered in topic 4.1 so this lesson has been written to include continual references to the content of that lesson. This enables links to be made between the movement across a cell membrane with the concentration gradient, the parts of the membrane that are involved and any features that may increase the rate at which the molecules move. A series of questions about the alveoli are used to demonstrate how a large surface area, a short diffusion distance and the maintenance of a steep concentration gradient will increase the rate of simple diffusion. One of two quick quiz rounds is then used to introduce temperature and size of molecule as two further factors that can affect simple diffusion. The remainder of the lesson focuses on facilitated diffusion and describes how transmembrane proteins are needed to move small, polar or large molecules from a high concentration to a lower concentration across a partially permeable membrane

This detailed lesson describes the fluid mosaic model of membrane structure and outlines the roles of the different components . Fully resourced, the PowerPoint and accompanying worksheets have been designed to cover specification point 4.1 (a) of the CIE International A-level Biology specification but as the membranes and target cells are discussed, points 4.1 (b) and © are also partially covered 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 2 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.

Adenosine triphosphate is the universal energy currency and this lesson focuses on the role of this molecule in cell. The PowerPoint has been designed to cover point1.2 © of the CIE International A-level Biology specification and also explains how ATP must be hydrolysed to release energy and then re-synthesised during respiration and photosynthesis in the mitochondria and chloroplast respectively. As students were introduced to the structure of DNA and RNA at GCSE, the start of this lesson challenges them on their knowledge of these polynucleotides so that they can recognise that ATP consists of adenine, ribose and three phosphate groups. In order to release the stored energy, ATP must be broken down and students will be given time to discuss which reaction will be involved as well as the products of this reaction. Time is taken to describe how the hydrolysis of ATP can be coupled to energy-requiring reactions within cells and the examples of active transport and skeletal muscle contraction are used as these are covered in greater detail in topics 4 and 15. The final part of the lesson considers how ATP must be re-synthesised and students will learn that this occurs in the mitochondria and chloroplast during aerobic respiration and photosynthesis respectively.

This fully-resourced lesson distinguishes between active and passive, natural and artificial immunity and explains how vaccinations can be used to control disease. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 11.2 (d) of the CIE A-level Biology specification and there is also a description and discussion on the concept of herd immunity. In topic 11.1, students were introduced to the primary and secondary immune responses so the start of this lesson uses an imaginary game of TOP TRUMPS to challenge them on the depth of their understanding. This will act to remind them that a larger concentration of antibodies is produced in a quicker time in the secondary response. The importance of antibodies and the production of memory cells for the development of immunity is emphasised and this will be continually referenced as the lesson progresses. The students will learn that this response of the body to a pathogen that has entered the body through natural processes is natural active immunity. Moving forwards, time is taken to look at vaccinations as an example of artificial active immunity. Another series of questions focusing on the MMR vaccine will challenge the students to explain how the deliberate exposure to antigenic material activates the immune response and leads to the retention of memory cells. A quick quiz competition is used to introduce the variety of forms that the antigenic material can take along with examples of diseases that are vaccinated against using these methods. The eradication of smallpox is used to describe the concept of herd immunity and the students are given time to consider the scientific questions and concerns that arise when the use of this pathway is a possible option for a government. The remainder of the lesson looks at the different forms of passive immunity and describes the drawbacks in terms of the need for a full response if a pathogen is re-encountered

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.

This lesson explains the importance of memory cells in the development of immunity and describes how the structure of antibodies is related to function. The PowerPoint and accompanying resources have been designed to cover specification points 11.1 (e) and 11.2 (a) as detailed in the CIE A-level Biology specification. As memory B cells differentiate into plasma cells that produce antibodies when a specific antigen is re-encountered, it was decided to link these two topic points in one lesson. The lesson begins by checking on the students incoming knowledge to ensure that they recognise that B cells differentiate into plasma cells and memory cells. This was introduced in a previous lesson on the specific immune response and students must be confident in their understanding if the development of immunity is to be understood. A couple of quick quiz competitions are then used to introduce key terms so that the structure of antibodies in terms of polypeptide chains, variable and constant regions and hinge regions are met. Time is taken to focus on the variable region and to explain how the specificity of this for a particular antigen allows neutralisation and agglutination to take place. The remainder of the lesson focuses on the differences between the primary and secondary immune responses and a series of exam-style questions will enable students to understand that the quicker production of a greater concentration of these antibodies in the secondary response is due to the retention of memory cells.

This engaging lesson describes how chromosome mutations result in changes to the number or structure of chromosomes and focuses on Downs and Turner’s syndrome. The PowerPoint and accompanying resources have been designed to cover specification points 2.3 (vi) and (vii) as detailed in the Edexcel A-level Biology B specification. A human karyotype which has not been altered by a mutation is studied at the start of the lesson to allow students to recall the usual number of chromosomes as well as the sex chromosomes. They are then challenged to identify the differences when presented with the karyotypes of sufferers of Downs, Turner’s and Klinefelter’s syndrome. Students will learn that in the majority of cases, these conditions are the result of non-disjunction and having been assisted in the explanation of the outcome for Downs and Klinefelters, they have to form their own for Turner’s. The remainder of the lesson looks at other types of mutations, including translocation, and students will also see how whole sets of chromosomes can be duplicated in polyploidy.

This fully-resourced lesson describes the events of the cell cycle so that students can understand how the genetic material behaves in interphase, mitosis and cytokinesis. The detailed PowerPoint and accompanying resources have been designed to cover specification points 2.3 (i), (ii) and (iii) as detailed in the Edexcel A-level Biology B specification. 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. An exam style question will check on their knowledge of the organelles from 2.1 and this acts to remind them that centrioles 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

This fully-resourced lesson describes how it’s possible for 1 gene to give rise to multiple products as a result of post-transcriptional modification of mRNA. The detailed PowerPoint and accompanying resources have been designed to cover point 7.2 (iii) of the Edexcel A-level Biology B specification. The lesson begins with a knowledge recall as the students have to recognise the definition of a gene as a sequence of bases on a DNA molecule that codes for a sequence of amino acids in a polypeptide chain. This description was introduced in topic 1 and the aim of the start of the lesson is to introduce the fact that despite this definition, most of the nuclear DNA in eukaryotes doesn’t actually code for proteins. A quick quiz competition is then used to introduce exons as the coding regions within a gene before students are challenged to predict the name of the non-coding regions and then to suggest a function for these introns. At this point, the students will complete a task that acts as a prior knowledge check where they have to identify the 6 errors in the descriptive passage about the lac operon and its role in the regulation of gene expression in prokaryotes. Moving forwards, pre-mRNA as a primary transcript is introduced and students will learn that this isn’t the mature strand that moves off to the ribosome for translation. Instead, a process called splicing takes place where the introns are removed and the remaining exons are joined together. Another quick quiz round leads to an answer of 20000 and students will learn that this is the number of protein-coding genes in the human genome. Importantly, the students are then told that the number of proteins that are synthesised is much higher than this value and a class discussion period encourages them to come up with biological suggestions for this discrepancy between the two numbers. The lesson concludes with a series of understanding and application questions where students will learn that alternative splicing enables a gene to produce more than a single protein and that this natural phenomenon greatly increases biodiversity.

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 fully-resourced lesson describes the role of transcription factors in the regulation of gene expression. The detailed PowerPoint and accompanying resources have been designed to cover the details of specification points 7.2 (i) and (ii) of the Edexcel A-level Biology B course. This is one of the more difficult concepts in this A-level course and therefore key points are reiterated throughout this lesson to increase the likelihood of student understanding and to support them when trying to make links to actual biological examples in living organisms. There is a clear connection to transcription and translation as covered in topic 1.4, so the lesson begins by reminding students that in addition to the structural gene in a transcription unit, there is the promotor region where RNA polymerase binds. Students are introduced to the idea of transcription factors and will understand how these molecules can activate or repress transcription by enabling or preventing the binding of the enzyme. At this point, students are challenged on their current understanding with a series of questions about DELLA proteins so they can see how these molecules prevent the binding of RNA polymerase. Their understanding is then tested again with another example with oestrogen and the ER receptor. The final and main section of the lesson focuses on the lac operon. Students will be able to visualise the different structures that are found in this unit of DNA and time is taken to go through the individual functions. A step by step guide is used to walk students through the sequence of events that occur when lactose is absent and when it is present before they are challenged to apply their understanding to an exam question.

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 has been written to support students to develop a clear understanding of 16 key genetic terms, including the 8 that are detailed in specification point 8.2 (i) of the Edexcel A-level Biology B specification. The 16 terms are genome, gene, chromosome, gene locus, homologous chromosomes, alleles, dominant, recessive, genotype, codominance, multiple alleles, autosomes, sex chromosomes, phenotype, homozygous and heterozygous. As some of these terms were met at GCSE, this fully-resourced lesson has been designed to include a wide range of activities that build on this prior knowledge and provide clear explanations as to their meanings as well as numerous examples of their use in both questions and exemplary answers. The main task provides the students with an opportunity to apply their understanding by recognising a dominance hierarchy in a multiple alleles characteristic and then calculating a phenotypic ratio when given a completed genetic diagram. Other tasks include prior knowledge checks, discussion points to encourage students to consider the implementation of the genetic terms and quiz competitions to introduce new terms, maintain engagement and to act as an understanding check.

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 worksheets that have been designed to cover point 8.2 (vi) of the Edexcel A-level Biology B specification The lesson includes a step-by-step guide to 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 8.2 (transfer of genetic information) and links are made throughout the lesson to earlier parts of this topic such as dihybrid inheritance as well as to earlier topics like meiosis