This lesson explains the meaning of 11 key terms associated with the genetic inheritance topic and challenges the students to use them in context. The PowerPoint and accompanying resources have been designed to cover point 6.1.6 of the AQA GCSE Biology specification and include explanations of genome, chromosome, gene, allele, genotype, homozygous, heterozygous, phenotype, dominant, recessive and gamete. The key term, genome, was met earlier in topic 6 so the lesson begins with a knowledge retrieval with the definition for this term. As the genome is the entire DNA of an organism, the next task challenges the students to identify three errors in a passage about DNA. This leads into discussions about chromosomes and genes and time is taken to explain that homologous chromosomes have the same genes at the exact same gene loci. The students will learn that alternative forms of the gene (alleles) can be found at these loci and that these structures explain the differences in inherited characteristics. Moving forwards, the main section of the lesson describes the link between the dominant and recessive alleles, homozygous and heterozygous genotypes, and the physical expression as the phenotype. The final key term is gamete, and the students are challenged to recognise a definition for this term using their knowledge of meiosis. Two progress and understanding checks complete the lesson and check on the students’ ability to recognise and write definitions for these 11 terms and to use them accurately in a written description

This lesson describes how the alveoli are adapted for gas exchange by diffusion between the air in the lungs and the blood capillaries. The PowerPoint and accompanying resource are part of the second lesson in a series of 2 which have been designed to cover the content of point 8.2 & 8.3 of the Edexcel GCSE Biology and Combined Science specifications. During the 1st lesson in this series, the students were shown how to calculate the surface area to volume ratio and so this lesson begins by challenging them to recall that the larger the organism, the smaller the ratio. This is done through the PLAY YOUR CARDS RIGHT format as shown in the cover picture, and leads into the key idea that complex multicellular organisms like humans have developed a range of different adaptations to increase this ratio at their exchange surfaces. Moving forwards, time is taken to consider and discuss how the following adaptations of the alveoli affect the rate of diffusion: large surface area lining of the alveoli consisting of a single layer of flattened cells maintenance of a steep concentration gradient Each feature is related to diffusion and current understanding and prior knowledge checks are used to allow the students to assess their progress and to challenge them to make links to other topics of the course. All exam questions have mark schemes embedded into the PowerPoint

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 lesson uses step by step guides to describe how to calculate the surface area to volume ratio. The PowerPoint and accompanying resources are part of the first lesson in a series of 2 lessons which have been designed to cover the detail of points 8.2 and 8.3 of the Edexcel GCSE Biology & Combined Science specifications. The calculation of the SA/V ratio can be an area of the course that students find difficult so this lesson breaks the calculation into parts to guide them through each step. The students are shown how to calculate the surface area, then the volume and then how to express the answer of the division calculation as a ratio against 1. After each step, the students are given the opportunity to apply their understanding and all questions have mark schemes with full workings embedded into the PowerPoint to allow the students to self-assess. Students also tend to struggle to see the relevance to Biology so the remainder of the lesson involves the calculation of the ratio for the alveoli in the human body. Students will discover that the surface area to volume ratio is significantly increased in these gas exchange surfaces which leads into the upcoming lesson on the adaptations of the alveoli to overcome the overall low ratio in larger organisms.

This lesson describes the role of meiotic cell division, including a detailed explanation of how 4 genetically unidentical daughter cells are formed. The PowerPoint and accompanying resources have been designed to cover point 3.3 of the Edexcel GCSE Biology and Combined Science specifications. The students covered the mitotic cell cycle in topic 2 and their knowledge of this type of cell division is utilised throughout the lesson to help with the understanding of this cycle. The lesson begins by challenging the students to recall the meaning of diploid and they will learn that the parent cell at the start of the meiotic cell cycle is a diploid cell. Time is taken to remind them of the events of interphase and then the lessons focuses on the 2 sets of division in meiosis which produces four haploid daughter cells. The identity of these cells as gametes is emphasised. The final part of the lesson uses a series of exam questions to challenge the students on their understanding of the cycle and the mark schemes are embedded into the PowerPoint to allow the students to assess their progress.

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 meaning of the terms stroke volume and heart rate and explains how to use them to calculate the cardiac output. The PowerPoint and accompanying resources have been designed to cover the content of specification point 8.12 of the Edexcel GCSE Biology & Combined Science specifications. The lesson begins by challenging the students to use their knowledge of the structure of the heart chambers to identify the one which has the most muscular wall. Their discussions should lead to the left ventricle and following the introduction of the key term stroke volume using a quick quiz competition, they will learn that this factor is the volume of blood pumped out of the left ventricle each heart beat. Another competition introduces the normative values for stroke volume and the resting heart rate and then the students are challenged to use the provided equation to calculate the cardiac output and to write a definition for this factor using their current understanding. The remainder of the lesson considers how these three factors change during exercise and they are challenged to apply their understanding through a series of exam questions. This worksheet is differentiated two ways and the mark scheme is embedded into the PowerPoint to allow the students to assess their progress.

This lesson describes the structure of DNA as a double-stranded polymer coiled into a double helix and focuses on nucleotides as the monomers. The PowerPoint and accompanying resources have been designed to cover the detail of point 3.4 of the Edexcel GCSE Biology & Combined Science specifications. The lesson begins with a reveal of the acronym DNA and students will learn that this stands for deoxyribonucleic acid. There is a focus on the use and understanding of key terminology throughout the lesson so time is taken to look at the meanings of the prefixes poly and mono as well as the suffix -mer. This leads into the description of DNA as a polymer which is made up of many monomers known as nucleotides. Students will be introduced to the three components of a DNA nucleotide and will learn that four different bases can be attached to the sugar. An observational task is used to get them to recognise that DNA consists of two strands and that complementary bases are joined by hydrogen bonds. Understanding checks are interspersed throughout the lesson along with mark schemes so that students can assess their progress

This lesson describes the effects of pH on the rate of an enzyme-catalysed reaction. The PowerPoint and accompanying resources are part of the second lesson in a series of 4 lessons which have been designed to cover the content of point 3.2 (a) of the CIE A-level Biology specification. The lesson begins with a short discussion, where the students are challenged to identify how the stomach and the small intestine differ in terms of a particular condition and to explain why the conditions in these neighbouring digestive organs are so important. This introduces pepsin and trypsin and these protease enzymes play a key role throughout the lesson as they are good examples of how different extracellular enzymes have different optimum pH values (which are not necessarily 7.0). Moving forwards, students will discuss how the rate of an enzyme-controlled reaction will change if there are small or large changes in pH, and then time is taken to ensure that students can explain these changes with reference to tertiary structure bonds and the shape of the active site. Through the use of a quick quiz competition, the students will be reminded of the key term “buffer” and a series of questions are used to challenge their understanding of how these substances could be used in a practical investigation. They will also learn how buffers are found in blood plasma as well as in red blood cells in the form of haemoglobin. As there is a considerable proportion of marks for Maths in a Biology context questions in the A-level assessments, the remainder of the lesson challenges the students to use a given formula to calculate the pH of blood when given the hydrogen ion concentration and to calculate percentage decrease. These questions have been differentiated to give assistance to those that need the support

This lesson describes the effects of pH on enzyme activity. The PowerPoint and accompanying resources are part of the first lesson in a series of 3 lessons which have been designed to cover the content of point 2.1.4 (d)(i)of the OCR A-level Biology A specification. The lesson begins with a short discussion, where the students are challenged to identify how the stomach and the small intestine differ in terms of a particular condition and to explain why the conditions in these neighbouring digestive organs are so important. This introduces pepsin and trypsin and these protease enzymes play a key role throughout the lesson as they are good examples of how different extracellular enzymes have different optimum pH values (which are not necessarily 7.0). Moving forwards, students will discuss how the rate of an enzyme-controlled reaction will change if there are small or large changes in pH, and then time is taken to ensure that students can explain these changes with reference to tertiary structure bonds and the shape of the active site. Through the use of a quick quiz competition, the students will be reminded of the key term “buffer” and a series of questions are used to challenge their understanding of how these substances could be used in a practical investigation. They will also learn how buffers are found in blood plasma as well as in red blood cells in the form of haemoglobin. With there being such a considerable proportion of marks for Maths in a Biology context questions in the A-level assessments, the remainder of the lesson challenges the students to use a given formula to calculate the pH of blood when given the hydrogen ion concentration and to calculate percentage decrease. These questions have been differentiated to give assistance to those that need the support Please note that this is a lesson which describes the effect on enzyme activity, as described in 2.1.4 (d)(i), and not the details of the practical investigation which is covered in a later lesson

This lesson describes the effects of pH on the rate of enzyme-controlled reactions. The PowerPoint and accompanying resources are part of the third lesson in a series of 5 lessons which have been designed to cover the content of point 1.4.2 (Many proteins are enzymes) of the AQA A-level Biology specification. The lesson begins with a short discussion, where the students are challenged to identify how the stomach and the small intestine differ in terms of a particular condition and to explain why the conditions in these neighbouring digestive organs are so important. This introduces pepsin and trypsin and these protease enzymes play a key role throughout the lesson as they are good examples of how different extracellular enzymes have different optimum pH values (which are not necessarily 7.0). Moving forwards, students will discuss how the rate of an enzyme-controlled reaction will change if there are small or large changes in pH, and then time is taken to ensure that students can explain these changes with reference to tertiary structure bonds and the shape of the active site. Through the use of a quick quiz competition, the students will be reminded of the key term “buffer” and a series of questions are used to challenge their understanding of how these substances could be used in a practical investigation. They will also learn how buffers are found in blood plasma as well as in red blood cells in the form of haemoglobin. With there being such a large proportion of marks for Maths in a Biology context questions in the AQA assessments, the remainder of the lesson challenges the students to use a given formula to calculate the pH of blood when given the hydrogen ion concentration and to calculate percentage decrease. These questions have been differentiated to give assistance to those that need the support

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 engaging lesson describes how chromosome mutations result in changes to the number or structure of chromosomes The PowerPoint and accompanying resources are part of the second lesson in a series of 2 lessons that have been designed to cover specification points (f) in topic 3 of A2 unit 4 of the WJEC A-level Biology specification, and there is a key focus on Down syndrome 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 Down, 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 Down 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 lesson describes the effects of gene mutations can have on amino acid sequences, as illustrated by sickle cell anaemia. The engaging and detailed PowerPoint and accompanying resources are part of the first lesson in a series of 2 lessons which have been designed to cover point (f) in topic 3 of A2 unit 4 of the WJEC A-level Biology specification and includes substitutions, deletions and insertions In order to understand how a change in the base sequence can affect the order of the amino acids, students must be confident in their understanding and application of protein synthesis which was covered earlier in this topic. Therefore, the start of the lesson focuses on transcription and translation and students are guided through the use of the codon table to identify amino acids. Moving forwards, a task called known as THE WALL is used to introduce to the names of three types of gene mutation whilst challenging the students to recognise three terms which are associated with the genetic code. The main focus of the lesson is substitutions and how these mutations may or may not cause a change to the amino acid sequence. The students are challenged to use their knowledge of the degenerate nature of the genetic code to explain how a silent mutation can result. Students will learn that a substitution is responsible for the new allele that causes sickle cell anaemia and they are tested on their understanding through an exam-style question. As with all of the questions, a mark scheme is included in the PowerPoint which can be displayed to allow the students to assess their understanding. The rest of the lesson looks at base deletions and base insertions and students are introduced to the idea of a frameshift mutation. One particular task challenges the students to evaluate the statement that base deletions have a bigger impact on primary structure than base substitutions. This is a differentiated task and they have to compare the fact that the reading frame is shifted by a deletion against the change in a single base by a substitution

This lesson guides students through the use of a chi-squared test to determine the significance of the difference between observed and expected results. It is fully-resourced with a detailed PowerPoint and differentiated worksheets that have been designed to cover point (d) in topic 3 of A2 unit 4 of the WJEC A-level Biology specification The lesson includes a step-by-step guide to demonstrates how to carry out the test in small chunks. At each step, time is taken to explain any parts which could cause confusion and helpful hints are provided to increase the likelihood of success in exam questions on this topic. Students will understand how to use the phenotypic ratio to calculate the expected numbers and then how to find the critical value in order to compare it against the chi-squared value. A worked example is used to show the working which will be required to access the marks and then the main task challenges the students to apply their knowledge to a series of questions of increasing difficulty. This lesson has been specifically designed to tie in with the previous lessons in this topic as there are regular references to dihybrid inheritance as well as to topics in the AS units like meiosis

This 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 fully-resourced lesson guides students through the principles of monohybrid inheritance, focusing on the importance of alleles. The PowerPoint and accompanying resources have been designed to cover points (a & b) in topic 3 of A2 unit 4 of the WJEC A-level Biology specification and includes the inheritance of alleles that demonstrate codominance. In order to minimise the likelihood of errors and misconceptions, step by step guides have been included throughout the lesson to support the students with the following: Writing parent genotypes Working out the different gametes that are made following meiosis Interpreting Punnett crosses to work out phenotypic ratios Students can often find pedigree trees the most difficult to interpret and to explain so exemplar answers are used as well as differentiated worksheets provided to support those students who need extra assistance