This lesson describes how the structure of the heart and the circulatory system is related to its function. The PowerPoint lesson and accompanying resources have been designed to cover the detail of point 8.8 of the Edexcel GCSE Biology and Combined Science specifications and includes descriptions of the role of the major blood vessels, the heart valves, and the relative thickness of the chamber walls. The lesson starts with an extract from Friends and challenges the students to recognise that full sized aortic pumps is a thesaurus version of big hearts. This reiterates the basic function of the heart that was met at KS2 and KS3 and moving forwards, the students will learn that it is the contraction of the cardiac muscle in the walls of the four heart chambers that allows this to happen. Students are provided with a diagram throughout the lesson which will be annotated as new structures are encountered and they begin by labelling the two atria and ventricles. The focus of the lesson is the relationship between structure and function so time is taken to consider the different roles of the atria and ventricles, as well as the right ventricle versus the left ventricle. Students will be able to observe from their diagram that the left ventricle has the thickest wall and they will be challenged to explain why later in the lesson once more detailed knowledge has been added. The next part of the lesson introduces the pulmonary artery and vein and a task challenges the students to consider the relationship between the heart and the lungs, and their prior knowledge of the adaptations of the alveoli is also tested. The remainder of the lesson discusses the double circulatory system and the heart valves. Understanding checks are found throughout the lesson and mark schemes are embedded into the PowerPoint to allow the students to assess their progress.

This lesson describes the key steps involved in transcription, the 1st stage of protein synthesis. The PowerPoint and accompanying resource are part of the first lesson in a series of 2 lessons which have been designed to cover the content of point 3.8 of the Edexcel GCSE Biology specification. According to the specification, the students are expected to know this process in considerable detail, and the lesson has been planned to reflect this. In a previous lesson in topic 3, the students were introduced to the definition of a gene as a section of a DNA molecule that codes for the sequence of amino acids in a protein. They will learn that this represents coding DNA, so time is then taken to explain that not all DNA codes for proteins and that there are sections of non-coding DNA located in front and behind each gene. This is vital information as it leads into the start of the process, where the binding of RNA polymerase to a section of non-coding DNA located in front of the gene is the trigger for the start of transcription of that particular gene. Moving forwards, a step by step guide describes the key steps which include the lining up of the RNA nucleotides against the exposed bases and the formation of mRNA through the reactions catalysed by RNA polymerase. Students are given key details of RNA nucleotides, specifically the inclusion of uracil bases, and an understanding check challenges them to determine the sequence of RNA bases that will line up against a template strand. These current understanding checks along with prior knowledge checks are found throughout the lesson to allow the students to assess their progress and to challenge them to make links to previous lessons.

This fully-resourced lesson has been designed to cover the specification point 3.21B (understanding the term co-dominance) as detailed in topic 3 (Reproduction and inheritance) of the Pearson Edexcel IGCSE Biology specification. The lesson uses the inheritance of the ABO blood group system to demonstrate co-dominance. A potentially difficult topic, time has been taken to include guidance sections where students are walked through the interpretation of the different genotypes to find out the phenotypes as well as supporting them through the construction of genetic diagrams and working out the blood groups from pedigree trees. There is a real focus on genetic terminology such as allele, locus, genotype and phenotype so that the understanding is deep and students can use this if they choose to further their studies at A-level. This lesson has been designed for GCSE-aged students studying the Pearson Edexcel IGCSE Biology course but is also suitable for older students who are learning about codominance (and multiple alleles) at A-level

This lesson describes the classification system that consist of a hierarchy of domain, kingdom, phylum, class, order, family, genus and species. The engaging PowerPoint and accompanying resource have been designed to cover point 3.1 (i) of the Edexcel A-level Biology B specification and also includes details of the use of the binomial naming system. The lesson begins by looking at the meaning of a population in Biology so that the term species can be introduced. A hinny, which is the hybrid offspring of a male horse and a female donkey, is used to explain how these two organisms must be members of different species because they are unable to produce fertile offspring. Moving forwards, students will learn that species is the lowest taxon in the modern-day classification hierarchy. A quiz runs throughout the lesson and this particular round will engage the students whilst they learn the names of the other 7 taxa and the horse and the donkey from the earlier example are used to complete the hierarchy. Students will understand that the binomial naming system was introduced by Carl Linnaeus to provide a universal name for each species and they will be challenged to apply their knowledge by completing a hierarchy for a modern-day human, by spotting the correct name for an unfamiliar organism and finally by suggesting advantages of this system.

This fully-resourced lesson describes the action of enzymes as biological catalysts and explains how their specificity is related to their 3D structure. The engaging PowerPoint and accompanying resources have been designed to cover points 2.10 (i) and (ii) of the Pearson Edexcel A-level Biology A specification but also introduces some examples of intracellular and extracellular enzymes to prepare students for the next lesson which covers 2.10 (iii). The lesson has been specifically planned to tie in with related topics that were previously covered such as protein structure, globular proteins and intracellular enzymes. This prior knowledge is tested through a series of exam-style questions along with current understanding and mark schemes are included in the PowerPoint so that students can assess their answers. Students will learn that enzymes are large globular proteins which contain an active site that consists of a small number of amino acids. Emil Fischer’s lock and key hypothesis is introduced to enable students to recognise that their specificity is the result of an active site that is complementary in shape to a single type of substrate. Time is taken to discuss key details such as the control of the shape of the active site by the tertiary structure of the protein. The induced-fit model is described so students can understand how the enzyme-susbtrate complex is stabilised and then students are challenged to order the sequence of events in an enzyme-controlled reaction. The lesson finishes with a focus on ATP synthase and DNA polymerase so that students are aware of these important intracellular enzymes when learning about the details of respiration and DNA replication.

This lesson describes how individuals may develop immunity, focusing on the different types that are active, passive, natural and artificial. The engaging PowerPoint and accompanying resources have been designed to cover point 6.1 of the Edexcel International A-level Biology specification and there is also a description and discussion of herd immunity to increase the relevance to the current epidemic with COVID-19. The lesson begins with a series of exam-style questions which challenge the students to demonstrate and apply their understanding of the immune response as covered in the previous lessons in this topic. In answering and assessing their answers to these questions, the students will recognise the differences between the primary and secondary immune responses and then a discussion period is included to encourage them to consider how the production of a larger concentration of antibodies in a quicker time is achieved. The importance of antibodies and the production of memory cells for the development of immunity is emphasised and this is 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 differences between the roles of the B cells and T cells in the body’s immune response. The PowerPoint and accompanying resources have been designed to cover points 6.9 & 6.10 in unit 4 of the Edexcel International A-level Biology specification and includes descriptions of the role of the antigens and the production of antibodies by plasma (effector) cells In the previous lesson on the non-specific responses, the students were introduced to macrophages and dendritic cells as antigen-presenting cells and the start of this lesson challenges their recall and understanding of this process. Time is taken to discuss how the contact between these cells and lymphocytes is critical for the initiation of the body’s (specific) immune response. Moving forwards, a quick quiz competition is used to introduce the names of the different T cells that result from differentiation. Their specific roles are described including an emphasis on the importance of the release of cytokines in cell signalling to activate other immune system cells. T memory cells are also introduced so that students can understand their role in immunological memory and active immunity as described in an upcoming lesson. The next part of the lesson focuses on the B cells and describes how clonal selection and clonal expansion results in the formation of memory B cells and effector cells. A series of understanding and application questions are then used to introduce the structure of antibodies and to explain how the complementary shape of the variable region allows the antigen-antibody complex to be formed. The lesson concludes by emphasising that the pathogen will be overcome as a result of the combination of the actions of phagocytes, T killer cells and the antibodies released by the effector cells

This lesson describes the principle components of the plasma membrane, focusing on the phospholipid bilayer and membrane proteins. The detailed PowerPoint and accompanying worksheets have been designed to cover the detail in point (a) of AS unit 1, topic 3 of the WJEC 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 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 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 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 describes the inheritance of two genes and guides students through the calculation of phenotypic ratios, before considering linkage. The PowerPoint and the accompanying resources have been designed to cover point [c] in topic 3 of A2 unit 4 of the WJEC A-level Biology specification. As the previous lesson described the construction of genetic crosses and pedigree diagrams, students are aware of the methods involved in writing genotypes and gametes for the inheritance of a single gene. Therefore, the start of this lesson builds on this understanding to ensure that students recognise that genotypes contain 4 alleles and gametes contain 2 alleles when two genes are inherited. The students are taken through the steps of a worked example to demonstrate the key steps in the calculation of a phenotypic ratio before 2 exam-style questions challenge them to apply their newly-acquired knowledge. Mark schemes are displayed within the PowerPoint to allow students to assess their progress. The phenotypic ratio generated as the answer to the next question is 9:3:3:1 and time is taken to explain that this is the expected ratio when two heterozygotes for two unlinked genes are crossed which they may be expected to use when meeting the chi squared test in an upcoming lesson The remainder of the lesson considers how linkage, where two genes have loci on the same chromosome, affects the outcome of dihybrid inheritance. This is a difficult topic which can be poorly understood by students so extra time was taken during the planning to split the concept into small chunks. There is a clear focus on using the number of parent phenotypes and recombinants in the offspring as a way 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 point of contact (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 and a link to the chi squared test which is covered in an upcoming lesson is also made. The main task of the lesson act as understanding check where students are challenged to analyse the results of genetic crosses involving the inheritance of the ABO blood group gene and the nail-patella syndrome gene n humans and also the inheritance of body colour and wing length in Drosophila.

This lesson describes sex linkage, focusing on the the inheritance of genes on the X chromosome that lead to haemophilia and Duchenne muscular dystrophy. The PowerPoint and accompanying resources have been designed to cover specification point [e] in topic 3 of A2 unit 4 of the WJEC A-level Biology specification. 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 and they will be challenged to find evidence to support this decision later in the lesson. In terms of humans, the lesson focuses on haemophilia 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 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 fully-resourced lesson describes the major routes that pathogens take when entering the body and the body’s barriers to this infection. The engaging and detailed PowerPoint and accompanying resources have been designed to cover points 6.7 (i) & (ii) of the Edexcel International A-level Biology specification and includes descriptions of the following barriers: skin the blood clotting process mucous membranes stomach acid vaginal acid and flora skin and gut flora wax in the ear canal There are clear links to topics 1, 2 and 3 in each of these barriers, so these are considered and discussed during each of the descriptions. For example, the presence of keratin in the cytoplasm of the skin cells allows the student knowledge of the properties of this fibrous protein to be checked. Other topics that are revisited during this lesson include protein structure, key terminology and the epithelium that lines the different parts of the airways. All of the exam-style questions have mark schemes that are embedded into the PowerPoint and a number of the tasks have been differentiated to allow students of differing abilities to access the work.

This detailed lesson describes the processes of PCR and electrophoresis to allow students to understand how gene sequencing can be used. The engaging PowerPoint and accompanying resource have been planned to cover the content of point 7.1 of the Edexcel A-level biology B specification. The lesson begins by comparing the number of genes in the genome with the number of base pairs, to allow students to learn that the bases in the genes only accounts for about 1.5% of the genome. This challenges them to recall that most is non-coding DNA, and the importance and usefulness of these sections are explored during the lesson. Moving forward, a step-by-step guide describes the key steps in the polymerase chain reaction, and time is taken at each step to qualify the fine details such as the use of Taq polymerase instead of human DNA polymerase. The remainder of the lesson focuses on the various uses of these DNA samples once they’ve been amplified by the PCR. The steps of the electrophoresis process are described and students will see how DNA profiling can be used in forensic science to identify criminals and for paternity tests. Understanding and prior knowledge checks are found throughout the lesson, along with the answers, to allow students to assess their grasp of the current topic as well as their ability to identify the links with previously covered topics.

This lesson describes the pathway by which the translation of mRNA into proteins can be prevented by siRNA and miRNA molecules. The engaging and detailed PowerPoint and accompanying resources are part of the final lesson in a series of 4 lessons that cover the detail of point 8.2.2 of the AQA A-level biology specification. The lesson begins with an exisiting knowledge check, as the students are challenged to recognise the processes of DNA methylation and histone acetylation, before RNA interference is introduced as another way by which gene expression is controlled in eukaryotes. Moving forwards, a quick quiz round introduces small interfering RNA (siRNA) and students will learn how this double-stranded, non-coding RNA is normally just 21 base pairs long. A step by step guide then describes the action of siRNA in preventing translation, through the cutting of the target mRNA into fragments which are then degraded. Time is taken to consider the possible application of siRNA molecules in the treatment of HIV and then cystic fibrosis, and the latter involves a series of exam-style questions which challenge the students on their understanding of this topic as well as the recall of content from the other 7 AQA topics. The remainder of the lesson focuses on microRNA (miRNA) and students will understand how this molecule is produced and how its action differs to that of siRNA in mammalian cells.