This fully-resourced lesson has been designed to cover the content of specification point 5.3.3 (Maintaining water and nitrogen balance in the body) as found in topic 5 of the AQA GCSE Biology specification. This resource contains an engaging and detailed PowerPoint (59 slides) and accompanying worksheets, which have been differentiated so that students of different abilities can access the work. The detail of the content and this resource means that it is likely to take more than 1 lesson to go through the tasks. The resource is filled with a wide range of activities, each of which has been designed to engage and motivate the students whilst ensuring that the key Biological content is covered in good detail. Understanding checks are included throughout so that the students can assess their grasp of the content. In addition, prior knowledge checks make links to content from earlier topics such as homeostasis, osmosis and active transport. The following content is covered in this lesson: The importance of controlled water levels for cellular function The ways that water is lost and removed from the body The formation of urea by deamination Filtration of the blood by the kidney Selective reabsorption of useful molecules from the kidney to the blood The effect of ADH on the permeability of the tubules of the kidney Dialysis and transplant as possible treatment options for kidney failure As stated at the top, this lesson has been designed for GCSE-aged students who are studying the AQA GCSE Biology course, but it can be used with A-level students who need to go back over the key points before looking at the function of the nephron in more detail

This lesson uses a step-by-step guide to describe the role of gibberellins in the germination of barley. The PowerPoint and accompanying resource have been planned to cover point (3) of topic 15.2 of the CIE A-level biology specification (for assessment in 2025 - 27). The lesson begins with a challenge, where the students must identify the term, germination, from a series of clues. They will learn that this is the development of a plant from a seed following a period of dormancy and involves gibberellins. A quick quiz round is then used to introduce the embryo, endosperm and aleurone layer in the structure of a barley seed. The process of seed germination can be divided into a sequence of 9 events and the main task of the lesson challenges the students to order these 9 events. However, this task has an extra level of difficulty as two of the events have been missed out, so the students must use the clues to predict the key biological processes in these events.

This detailed and engaging lesson supports students with their revision in the build up to their PAPER 1 (Biological processes) mocks or final assessment. The wide range of tasks and activities will challenge them on their knowledge of modules 1, 2, 3 and 5 of the OCR A-level biology A specification, allowing them to identify any areas which require further attention before the examinations. Included in the range of tasks are exam-style questions and understanding checks and all answers are embedded into the PowerPoint. There are quiz rounds to maintain engagement and to encourage healthy competition, as well as guided discussion periods to provide opportunities for students to support each other. The following content is directly covered by this revision lesson: The nature of the genetic code Globular and fibrous proteins Protein structure The role of the heart valves in the cardiac cycle The conduction system of the heart The autonomic control of heart rate The mitotic cell cycle DNA replication The events of meiosis that contribute to genetic variation The structure of starch and cellulose The light-dependent and light-independent reactions of photosynthesis The ultrastructure of eukaryotic cells Calculating the size of an object under the optical microscope Saltatory conduction The structure and function of sensory and motor neurones Depolarisation and the initiation of an action potential Many of the tasks have been differentiated to maintain challenge whilst providing access to all. This is an extensive lesson with many tasks so it is estimated that it will take over 3 hours of teaching time if covered in full, but teachers may choose to use sections to focus on a specific topic. If you and your students enjoy this lesson and find it beneficial, a revision challenging the content of modules 1, 2, 4 & 6 as assessed in PAPER 2 (Biological diversity) has also been uploaded.

This lesson describes the role of gibberellin in stem elongation, including the role of the dominant allele, Le, and the recessive allele, le. The PowerPoint and accompanying resources have been designed to cover specification point 16.2 (7) of the CIE A-level biology specification (for assessment in 2025-27). The lesson begins with the introduction of the Le gene loci, along with some initial details of this gene’s regulation of height in some plants. The students met gibberellin in topic 15, so the first of several prior knowledge checks is used to challenge them to recall the name of this plant hormone from a description about seed germination. Moving forwards, the students will learn that the enzyme encoded for by the Le gene is involved in the gibberellin synthesis pathway, where it catalyses the conversion of the inactive precursor GA20 to GA1, which is active gibberellin. As this lesson is part of topic 16, the genetics that underpins the biology is continually referenced, and again, an exam-style question is used to ensure that students recognise that homozygous dominant and heterozygous genotypes would be expressed as tall plants. The rest of the lesson considers the recessive allele, and how the substitution of alanine with threonine affects the shape of the active site, rendering the enzyme as non-functional. All answers to the knowledge checks are embedded into the PowerPoint to allow students to assess their progress.

This lesson describes the role of gibberellin in stem elongation, and considers the experimental evidence which supports this theory. The PowerPoint and accompanying resources have been designed to cover specification point 5.1.5 (d) as set out in the OCR A-level biology A specification. The lesson begins with the introduction of the Le gene loci, along with some initial details of this gene’s regulation of height in some plants. The students met gibberellin in a previous lesson in this module on the roles of plant hormones, so the first of several prior knowledge checks is used to challenge them to recall the name of this plant hormone from a description about seed germination. Moving forwards, the students will learn that the enzyme encoded for by the Le gene is involved in the gibberellin synthesis pathway, where it catalyses the conversion of the inactive precursor GA20 to GA1, which is active gibberellin. As this lesson is normally taught before patterns of inheritance in module 6.2.1, a step-by-step guide is used to describe how to use a genetic diagram to predict the phenotypic outcomes. An exam-style question is used to ensure that students recognise that homozygous dominant and heterozygous genotypes would be expressed as tall plants. The next part of the lesson considers the recessive allele, and how the substitution of alanine with threonine affects the shape of the active site, rendering the enzyme as non-functional. The final part of the lesson looks at examples of investigations which have been used to obtain experimental evidence which support the theory of the role of gibberellin in stem elongation. All answers to the knowledge checks are embedded into the PowerPoint to allow students to assess their progress. The role of gibberellin in seed germination is covered in “The roles of plant hormones” lesson which has been uploaded for free.

This lesson describes the steps involved in the closure of the Venus flytrap as a response to touch by an insect or an arachnid. The PowerPoint and accompanying resources have been designed to cover the detail of point (1) of topic 15.2 of the CIE A-level biology specification (for assessment in 2025 - 27). The lesson begins with a recall of tropisms as directional growth responses in plants and a short amount of time is allocated to discuss the importance of phototropism and gravitropism. This leads into the introduction of thigmotropism as a directional response to touch, before the students will learn that the closure of the Venus flytrap is an example of a thigmonastic response, a response that’s independent of direction. The students are presented with a passage that describes the classification, and structure of the Venus flytrap, as well as the stimulus that results in the closure. They must answer 8 exam-style questions on the content of the passage, which challenges their understanding of the current topic and links to other topics such as organelles and biological molecules. All answers are embedded into the PowerPoint to allow students to assess their progress. The rest of the lesson focuses on the steps involved in the mechanism of closure, including the detection of touch by the sensors in the trigger hairs, the movement of ions, and the elongation of the cells in the lobes of the modified leaves.

This fully-resourced lesson describes the stages of meiosis and specifically the events which contribute to genetic variation. The detailed PowerPoint and accompanying resources have been designed to cover specification points 2.3 (iv) & (v) of the Edexcel A-level Biology B specification and includes description of crossing over, independent assortment and the production of haploid gametes In order to understand how the events of meiosis like crossing over and random assortment and independent segregation can lead to variation, students need to be clear in their understanding that DNA replication in interphase results in homologous chromosomes as pairs of sister chromatids. Therefore the beginning of the lesson focuses on the chromosomes in the parent cell and this first part of the cycle and students will be introduced to non-sister chromatids and the fact that they may contain different alleles which is important for the exchange that occurs during crossing over. Time is taken to go through this event in prophase I in a step by step guide so that the students can recognise that the result can be new combinations of alleles that were not present in the parent cell. Moving forwards, the lesson explores how the independent segregation of chromosomes and chromatids during anaphase I and II results in genetically different gametes. The final part of the lesson looks at the use of a mathematical expression to calculate the possible combinations of alleles in gametes as well as in a zygote following the random fertilisation of haploid gametes. Understanding and prior knowledge checks are interspersed throughout the lesson as well as a series of exam questions which challenge the students to apply their knowledge to potentially unfamiliar situations.