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 the meaning of an isotope and explains how to calculate the relative atomic mass using the relative masses and abundance of its isotopes. The PowerPoint and accompanying resources have been designed to cover the detail of points 1.9, 1.11 & 1.12 of the Edexcel GCSE Chemistry & Combined Science specifications. The early topic 1 lessons covered the meaning of the atomic and mass number and the calculation of the number of subatomic particles, and this lesson begins by challenging the recall of this key information. Moving forwards, a quick quiz competition is used to introduce the term “isotope” and then the students have to calculate the number of subatomic particles in K-39, K-40 and K-41 before using their answers to complete a definition about these types of substances. Time is taken to explain how isotopes are represented in standard annotation and the importance of the mass number is emphasised. A series of application questions are used to challenge them to apply their understanding and knowledge and mark schemes are embedded into the PowerPoint to allow the students to self-mark. The remainder of the lesson explains how the existence of isotopes results in some elements having relative atomic masses that are not whole numbers and then explains how these masses can be calculated. Once an example is demonstrated, the students are again given the chance to apply their understanding to a series of questions, and this exam question worksheet has been differentiated two ways

This lesson introduces and explains the meaning of 11 key terms associated with the genetic inheritance topic. The PowerPoint and accompanying resources have been designed to cover point 6.1.6 of the AQA GCSE Combined Science 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 challenges their recall of the structure of this chemical as a double helix, its location in an eukaryotic cell in the nucleus and an understanding that the gene codes for the sequence of amino acids in a specific protein. 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 succession as the gradual, progressive changes that occur in a community over time. The PowerPoint and accompanying resources are part of lesson 3 in a series of 4 lessons which have been planned to cover the content included in topic 7.4 of the AQA A-level biology specification. In line with the specification, the lesson describes primary succession and explains how the community changes from the initial colonisation by the pioneer species to the establishment of a climax community. Time is taken to focus on the lichen as a pioneer species and to explain how their actions lead to the production of soil and the subsequent colonisation by more hardy species. The island of Surtsey is used as a real-world example to deepen student understanding. Understanding checks and prior knowledge checks are embedded throughout the lesson (along with the answers) so students can assess their progress on the current topic and also test their ability to link to previously covered topics. Due to the high mathematical content of the AQA assessments, a maths in a biology context question has also been included.

This lesson describes the biological meaning of species, populations, gene pool and allele frequency and explains how these terms are linked. The PowerPoint and accompanying resources are part of the 1st lesson in a series of 2 lessons that cover the detail of specification point 7.2 (Populations) of the AQA A-level biology. The two living species of the African elephant, the forest and bush elephant, are used as examples to demonstrate the meaning of species and to show how they exist as one or more populations. A quick quiz introduces the term gene pool in an engaging way and then the allele frequency of three versions of the GBA gene demonstrates how these frequencies can change in small populations. In doing so, students are briefly introduced to genetic drift which they will encounter in an upcoming topic. The students are challenged throughout the lesson with understanding checks and prior knowledge checks as well as exam-based questions where they have to comment on the validity of a scientist’s conclusion. The other lesson in topic 7.2 is the Hardy-Weinberg principle.

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

This 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.

This revision lesson provides students with the opportunity to assess their understanding of nucleic acids and protein synthesis (topic 6). The lesson includes a multiple-choice assessment of 10 questions and a PowerPoint containing the answers, where each answer slide shows the exact specification code to enable students to note the areas which may require extra attention. The PowerPoint also contains additional questions to challenge content from topic 6 of the CIE A-level biology specification (2025 - 2027 update) that isn’t directly covered by the 10 questions, and prior knowledge checks to encourage students to make links to content from topics 1 - 5. This lesson has been designed to be used at the end of topic 6, and in the build up to mocks and the final A-level assessments.

This revision lesson provides students with the opportunity to assess their understanding of homeostasis (topic 14). The lesson includes a multiple-choice assessment of 10 questions and a PowerPoint containing the answers, where each answer slide shows the exact specification code to enable students to note the areas which may require extra attention. The PowerPoint also contains additional questions to challenge content from topic 14 of the CIE A-level biology specification (2025 - 2027 update) that isn’t directly covered by the 10 questions, and prior knowledge checks to encourage students to make links to content from any of topics 1 - 13.

This revision lesson uses a multiple-choice assessment to challenge the students on their understanding of topic 8, the control of gene expression. In addition to the 20 question assessment, this lesson includes a PowerPoint where the answers are revealed and additional questions are posed about the content of topic 8 which isn’t directly challenged in the questions. The PowerPoint also contains prior knowledge checks on content from topics 1, 3, 4 and 6. Revision lessons of this format which challenge topics 1 - 7 are also uploaded.

This lesson guides students through the stages of the nitrogen cycle, focusing on the vital roles performed by microorganisms in this cycle. The detailed PowerPoint and accompanying resources are part of the 1st lesson in a series of 3 lessons which have been planned to cover point 5.4 (nutrient cycles) of the AQA A-level biology specification. The lesson begins by challenging students to recall two monomers containing nitrogen that were met in topic 1, allowing them to recognise that this chemical element is a key component of nucleotides in DNA and amino acids, which are needed to synthesise proteins. Moving forwards, they will learn that despite the high % of nitrogen in the Earth’s atmosphere, it cannot be used directly by plants, and therefore plants need a supply of “fixed” nitrogen. A diagram is constantly updated and displayed as new information is introduced and this supports their understanding. The students will discover that microorganisms are involved in nitrogen fixation, decomposition and ammonification, nitrification, and denitrification. As each of these biological actions is introduced, time is spent considering key details and understanding checks are used to allow the students to assess their progress. There are also several prior knowledge checks, where students are encouraged to make links to content met in topics 1 - 4. Answers to all questions are embedded into the PowerPoint.

This lesson describes the main characteristics of benign and malignant tumours. The PowerPoint and accompanying resource are part of the 1st lesson in a series of 2 lessons which have been planned to cover the content of point 8.2.3 of the AQA A-level biology specification. This lesson begins by challenging the students to recognise the process of mitosis from a single clue. This single clue is “a controlled process” and has been designed to remind them that mitosis is a process controlled by genes. A quick quiz round challenges their recall of the details of the mitotic cell cycle to reveal the key term, tumour, and this introduces the idea that a mutation to one of the genes leads to uncontrolled cell division and the formation of tumours. Moving forwards, the lesson considers the features of benign tumours, beginning with the key point that these masses of cells are not cancerous. Students will learn that their growth rate is slower than malignant tumours, and due to a covering of fibrous connective tissue, the cells do not invade neighbouring tissues. However, the lesson points out that due to mass effect, benign tumours can cause secondary pathological effects such as organ damage. This leads into a task where the students are challenged on their knowledge of osmoregulation, digestion and blood glucose regulation to identify the tissues which are impacted. The rest of the lesson describes the features of malignant tumours and time is spent considering how the ability of these cells to metastasise makes them so dangerous.