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 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 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 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.