This revision lesson contains an assessment of 20 multiple-choice questions and a PowerPoint with the answers and related key points from the specification. The 20 questions have been written to cover the content of topic 4 of the AQA A-level biology specification, providing the students with an opportunity to assess their understanding and highlight those areas which need further attention. All 7 sub-topics of topic 4 are covered by at least one question and there are several questions which challenge mathematical skills, which aligns with the high mathematical content of the final assessments.

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 how recombinant DNA can be produced, including the role of restriction endonucleases and DNA ligase. The PowerPoint and accompanying resources have been designed to cover the content of point 7.4 (i) of the Edexcel A-level Biology B specification. This lesson begins with the introduction of recombinant DNA technology as a process where fragments of DNA are transferred from one species to another. Over the course of the lesson, the students are guided through 5 steps in the production of the recombinant DNA, with a focus on the enzymes involved, which are reverse transcriptase, DNA polymerase, restriction endonuclease, and DNA ligase. Understanding checks and prior knowledge checks are used throughout the lesson and the answers are embedded into the PowerPoint to allow the students to assess their progress.

This lesson describes how iPS cells are formed from fibroblasts and discusses why this method is less controversial than the use of embryonic stem cells. The PowerPoint and accompanying resources are part of the 2nd lesson in a series of 2 lessons which covers the content of point 7.3 (stem cells) of the Edexcel A-level biology B specification. The lesson begins with a SPOT THE ERRORS task, where students have to use their knowledge of pluripotent cells from the previous lesson to identify the 3 errors and make corrections. The aim of this task is to remind them that pluripotent cells are found in embryos and can divide in unlimited numbers before finally becoming fully differentiated somatic cells. Moving forwards, the students are introduced to fibroblasts as examples of these somatic cells and the opportunity is taken to challenge their knowledge of collagen as this is a substance produced by these cells. The answers are embedded into the PowerPoint to allow the students to assess their recall of this topic 1 content. A quick quiz is used to introduce the acronym iPS and students will learn that fibroblasts can be reprogrammed to form induced pluripotent cells using specific transcription factors. The remainder of the lesson challenges them to answer questions about the use of iPS cells in regenerative medicine after reading a passage about an example. This allows them to recognise that deriving these cells from adult tissues as opposed to embryonic stem cells raises less problems and the transplant into the same person reduces the risk of rejection.

This detailed lesson describes how gene expression can be changed by epigenetic modification, which is important in ensuring cell differentiation. The PowerPoint and accompanying resources describe DNA methylation, histone modification, and non-coding RNA as methods of modification and are part of the final lesson in a series of 3 lessons that cover the content in point 7.2 of the Edexcel A-level biology B specification (Factors affecting gene expression). HIV, atherosclerosis and cystic fibrosis are included in the lesson to demonstrate the application of this control of gene expression in real biological examples. Students are challenged throughout the lesson on their current understanding as well as their knowledge of previously covered topics which have links and the answers are embedded into the PowerPoint to allow them to assess their progress. The other lessons in this series are uploaded and are titled “transcription factors” and “RNA splicing”.

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 lesson describes how epigenetic changes like DNA methylation and histone modification can modify the activation of certain genes. The PowerPoint and accompanying resources have been planned to cover points 3.14 ii & iii of the Pearson Edexcel A-level biology (Salters-Nuffield) specification. The lesson begins by introducing the prefix epi- as meaning on or above in Greek to allow students to recognise that epigenetics refers to changes in gene function due to factors beyond the genetic code. Moving forwards, they will learn that DNA methylation involves the attachment of a methyl group to cytosine and will come to understand how this inhibits transcription. They are challenged to recognise the pathogenesis of atherosclerosis through a variety of tasks before reading through a source detailing the results of a study between this cardiovascular condition and DNA methylation. The remainder of the lesson considers how the acetylation of histone proteins affects the expression of genes. Understanding and prior knowledge checks are embedded throughout the lesson (along with the answers) to allow the students to assess their progress on this topic and to encourage them to make links to the content of topics 1 - 2.

This lesson describes how epigenetics, in the form of increased DNA methylation and decreased histone acetylation, controls gene expression. The PowerPoint and accompanying resources are part of the second lesson in a series of 4 which cover the content of point 8.2.2 (regulation of transcription and translation) of the AQA A-level biology specification. As shown in the cover image, the lesson begins with a challenge, where the students have to recognise the prefix epi. They will learn that this prefix means on or above in Greek meaning epigenetics can be described as factors causing changes to gene function beyond the genetic code. One of several discussion periods is used to encourage them to identify what is not involved here (i.e. gene mutations), and so, epigenetics is introduced as heritable changes in gene function without changes to the base sequence. Moving forwards, the process of DNA methylation is introduced, and students are challenged to predict how the addition of a methyl group could inhibit transcription before they have to use their prior knowledge of key terms to complete a passage about this concept. The details of a study which considered the correlation between DNA methylation and atherosclerosis are provided to broaden their knowledge and then they have to answer questions about the study using their knowledge of content from topics 1 - 7. The remainder of the lesson discusses acetylation and students will learn that the removal of acetyl groups from histones causes the chromatin to become highly condensed and prevents the transcription of the gene.

This lesson describes how only part of a cell’s DNA is translated and explains how the potency of a stem cell determines its ability to specialise. The engaging and detailed PowerPoint and accompanying resources have been planned to cover all of the content in point 8.2.1 of the AQA A-level biology specification. The lesson begins by challenging the students to recall any existing knowledge of stem cells, to check that they remember that these cells differentiate, before the concept of cell potency is introduced to allow them to recognise that not all cells can differentiate into the same amount of cell types. A quick quiz is used to introduce pluripotency, unipotency, totipotency and multipotency before they are challenged to use their understanding of language to order these along the potency continuum. Beginning with totipotency, time is taken to go through details of each of these cell types, including where these cells are located. During the section of the lesson considering pluripotency, induced pluripotent stem cells are discussed and their potential for use in regenerative medicine is explored. Understanding checks through exam-based questions are embedded throughout the lesson (as well as the answers) to allow students to assess their current understanding and to address any gaps immediately. There are also prior knowledge checks so students can link to other topics from the specification and there is a maths in biology question so their mathematical skills are challenged in line with that element of the course.

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 fully-resourced lesson describes the stages of succession from colonisation to climax community. The PowerPoint and accompanying worksheets have been designed to cover the content of point 5.4 of the Edexcel A-level Biology A specification. As you can see from the cover image, this lesson uses a step-by-step method to guide the students through each stage of the process of succession, explaining each of the gradual, progressive changes that occur in a community over time. At each stage, time is taken to consider the organisms involved. There is a focus on lichens as examples of pioneer species and students will understand how colonisation by these organisms is critical to provide organic matter and to turn the bare ground into soil so it is habitable by other species. The island of Surtsey in Iceland is used as real-world example and shows how different parts of an area can be at different stages of succession. Understanding and prior knowledge checks are embedded into the PowerPoint (along with the answers) to allow students to assess their progress against the current topic and to encourage them to make links to previously-covered work.

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 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 extensive revision lesson challenges students on their knowledge and understanding of the content of topics 5 - 8 of the AQA A-level specification. The PowerPoint and accompanying resources are detailed and engaging and contain a selection of tasks which challenge the following points: Directional, stabilising and disruptive selection Saltatory conduction and other factors affecting conductance speed The structure of a motor neurone Sensory receptors, depolarisation and initiation of an action potential Hardy-Weinberg principle Genetic terminology Codominance and sex-linkage Autosomal linkage Chi-squared test Phosphorylation The stages of aerobic respiration Explaining lower ATP yields in anaerobic respiration Skeletal muscle contraction Structure and function of slow and fast twitch muscle fibres The control of heart rate Electrophoresis and genetic fingerprinting The secondary messenger model The students are tested through a variety of tasks including exam questions, understanding checks, and quiz rounds to maintain engagement. Due to the mathematical content in all A-level exams, there is also a focus on these skills. The answers to all questions are embedded into the PowerPoint so students can use this resource outside of the classroom. The delivery of the whole lesson will likely need at least 2 or 3 hours of contact time so this resource could be used with students in the final weeks building up to their paper 2 exam, or alternatively with students before their mocks on these topics.