This detailed lesson describes how the movement of water between solutions and cells has differing effects on animal and plant cells. Both the PowerPoint and accompanying resources have been designed to cover specification points 4.2 (a) and (f) as detailed in the CIE International A-level Biology specification. It’s likely that students will have used the term concentration in their osmosis definitions at GCSE, so the aim of the starter task is to introduce water potential to allow students to begin to recognise osmosis as the movement of water molecules from a high water potential to a lower potential, with the water potential gradient. Time is taken to describe the finer details of water potential to enable students to understand that 0 is the highest value (pure water) and that this becomes negative once solutes are dissolved. Exam-style questions are used throughout the lesson to check on current understanding as well as prior knowledge checks which make links to previously covered topics such as the lipid bilayer of the cell membrane. The remainder of the lesson focuses on the movement of water when animal and plant cells are suspended in hypotonic, hypertonic or isotonic solutions and the final appearance of these cells is described, including any issues this may cause.

This fully-resourced lesson describes the role of transcription factors in the regulation of gene expression. The detailed PowerPoint and accompanying resources have been designed to cover the details of specification points 7.2 (i) and (ii) of the Edexcel A-level Biology B course. This is one of the more difficult concepts in this A-level course and therefore key points are reiterated throughout this lesson to increase the likelihood of student understanding and to support them when trying to make links to actual biological examples in living organisms. There is a clear connection to transcription and translation as covered in topic 1.4, so the lesson begins by reminding students that in addition to the structural gene in a transcription unit, there is the promotor region where RNA polymerase binds. Students are introduced to the idea of transcription factors and will understand how these molecules can activate or repress transcription by enabling or preventing the binding of the enzyme. At this point, students are challenged on their current understanding with a series of questions about DELLA proteins so they can see how these molecules prevent the binding of RNA polymerase. Their understanding is then tested again with another example with oestrogen and the ER receptor. The final and main section of the lesson focuses on the lac operon. Students will be able to visualise the different structures that are found in this unit of DNA and time is taken to go through the individual functions. A step by step guide is used to walk students through the sequence of events that occur when lactose is absent and when it is present before they are challenged to apply their understanding to an exam question.

This fully-resourced lesson describes how it’s possible for 1 gene to give rise to multiple products as a result of post-transcriptional modification of mRNA. The detailed PowerPoint and accompanying resources have been designed to cover point 7.2 (iii) of the Edexcel A-level Biology B specification. The lesson begins with a knowledge recall as the students have to recognise the definition of a gene as a sequence of bases on a DNA molecule that codes for a sequence of amino acids in a polypeptide chain. This description was introduced in topic 1 and the aim of the start of the lesson is to introduce the fact that despite this definition, most of the nuclear DNA in eukaryotes doesn’t actually code for proteins. A quick quiz competition is then used to introduce exons as the coding regions within a gene before students are challenged to predict the name of the non-coding regions and then to suggest a function for these introns. At this point, the students will complete a task that acts as a prior knowledge check where they have to identify the 6 errors in the descriptive passage about the lac operon and its role in the regulation of gene expression in prokaryotes. Moving forwards, pre-mRNA as a primary transcript is introduced and students will learn that this isn’t the mature strand that moves off to the ribosome for translation. Instead, a process called splicing takes place where the introns are removed and the remaining exons are joined together. Another quick quiz round leads to an answer of 20000 and students will learn that this is the number of protein-coding genes in the human genome. Importantly, the students are then told that the number of proteins that are synthesised is much higher than this value and a class discussion period encourages them to come up with biological suggestions for this discrepancy between the two numbers. The lesson concludes with a series of understanding and application questions where students will learn that alternative splicing enables a gene to produce more than a single protein and that this natural phenomenon greatly increases biodiversity.

This fully-resourced lesson has been written to support students to develop a clear understanding of 16 key genetic terms, including the 8 that are detailed in specification point 8.2 (i) of the Edexcel A-level Biology B specification. The 16 terms are genome, gene, chromosome, gene locus, homologous chromosomes, alleles, dominant, recessive, genotype, codominance, multiple alleles, autosomes, sex chromosomes, phenotype, homozygous and heterozygous. As some of these terms were met at GCSE, this fully-resourced lesson has been designed to include a wide range of activities that build on this prior knowledge and provide clear explanations as to their meanings as well as numerous examples of their use in both questions and exemplary answers. The main task provides the students with an opportunity to apply their understanding by recognising a dominance hierarchy in a multiple alleles characteristic and then calculating a phenotypic ratio when given a completed genetic diagram. Other tasks include prior knowledge checks, discussion points to encourage students to consider the implementation of the genetic terms and quiz competitions to introduce new terms, maintain engagement and to act as an understanding check.

This fully-resourced lesson describes the ultrastructure of a prokaryotic cell including the cell wall, capsule,plasmid, flagellum, pili, ribosomes, mesosomes and circular DNA. The engaging PowerPoint and accompanying resources have been designed to cover the specification point 3.4 that is detailed in the Pearson Edexcel A-level Biology A specification but also makes continual references to eukaryotic cells as covered in 3.1 - 3.3 so that comparisons can be made. A clear understanding of terminology is important for A-level Biology so this lesson begins with a challenge, where the students have to come up with a 3-letter prefix that they believe will translate as before or in front of . This leads into the discovery of the meaning of prokaryote as before nucleus which acts to remind students that these types of cell lack this cell structure. Links to the previous lessons on the eukaryotic cells are made throughout the lesson and at this particular point, the students are asked to work out why the DNA would be described as naked and to state where it will be found in the cell. Moving forwards, the students will discover that these cells also lack membrane bound organelles and a quick quiz competition challenges them to identify the specific structure that is absent from just a single word. In addition to the naked DNA, students will learn that there are also ribosomes in the cytoplasm and will discover that these are smaller than those found in the cytoplasm of an eukaryotic cell (but the same size as those in chloroplasts and mitochondria). The remainder of the lesson focuses on the composition of the cell wall, the additional features of prokaryotic cells such as plasmids and there is also the introduction of binary fission as the mechanism by which these organisms reproduce so that students can recognise that prokaryotic cells do not contain centrioles

This detailed lesson describes the properties of water to demonstrate the importance of this molecule for living organisms. The engaging PowerPoint and accompanying resource have been designed to cover the details of specification point (b) of AS unit 1, topic 1 of the WJEC A-level Biology course and has been specifically designed to ensure that each role is illustrated using a specific example. As this is only the second lesson in the biological compounds topic, which is a topic that students tend to find difficult or potentially less engaging, the planning has centred around the inclusion of a wide variety of tasks to cover the content whilst maintaining motivation and engagement. These tasks include current understanding and prior knowledge checks, discussion points and quick quiz competitions to introduce key terms and values in a memorable way. The start of the lesson considers the structure of water molecules, focusing on the covalent and hydrogen bonds, and the dipole nature of this molecule. Time is taken to emphasise the importance of these bonds and this property for the numerous roles of water and then over the remainder of the lesson, the following properties are described and discussed and linked to real-life examples: polarity ability to form hydrogen bonds surface tension as a solvent thermal properties as a metabolite The final part of the lesson introduces condensation and hydrolysis reactions and students will learn that a clear understanding of these reactions is critical as they will reappear throughout the topic in the synthesis and breakdown of biological compounds

This fully-resourced lesson describes how DNA is replicated semi-conservatively, including the roles of DNA helicase, polymerase and ligase. The detailed PowerPoint and accompanying resources have been designed to cover point 1.4 (ii) of the Edexcel A-level Biology B specification The main focus of this lesson is the roles of DNA helicase in the breaking of the hydrogen bonds between nucleotide bases, DNA polymerase in forming the growing nucleotide strands and DNA ligase in the joining of the nucleic acid fragments. Time is taken to explain key details, such as the assembly of strands in the 5’-to-3’ direction, so that the continuous manner in which the leading strand is synthesised can be compared against that of the lagging strand. The students are constantly challenged to make links to previous topics such as DNA structure and hydrolysis reactions through a range of exam questions and answers are displayed so that any misconceptions are quickly addressed. The main task of the lesson asks the students to use the information provided in the lesson to order the sequence of events in DNA replication before discussing how the presence of a conserved strand and a newly built strand in each new DNA molecule shows that it is semi-conservative.

This detailed lesson describes the process of translation at the ribosome and includes detailed descriptions of the roles of the mRNA, tRNA and rRNA. The PowerPoint and accompanying resources have been designed to cover the second part of point 1.4 (vi) of the Edexcel A-level Biology B specification and this lesson also includes continual links to the previous lessons in this topic on transcription and the structure of DNA and RNA. Translation is a topic which is often poorly understood and so this lesson has been written with the aim of supporting the students to answer the different types of questions that can arise. The lesson begins by challenging the students to consider why it is so important that the amino acids are assembled in the correct order during the formation of the chain. Moving forwards, a quick quiz round called “LOST IN TRANSLATION” is used to check on their prior knowledge of the mRNA strand, the tRNA molecules and the ribosomes. The next task involves a very detailed description of translation that has been divided into 14 statements which the students have to put into the correct order. By giving them a passage of this detail, they can pick out the important parts to use in the next task where they have to answer shorter questions worth between 3 and 4 marks. These types of questions are common in the assessments and by building up their knowledge across the lesson, their confidence to tackle this type of question should increase. The final two tasks of the lesson involve another quiz, where the teams compete to transcribe and translate in the quickest time before using all that they have absorbed to answer some questions which involve the genetic code and the mRNA codon table

This engaging lesson describes how the structure and properties of phospholipids relate to their functions in cell membranes. The PowerPoint has been designed to cover point 1.2 (iv) as detailed in the Edexcel A-level Biology B specification and includes regular references to the previous lesson on triglycerides to check on knowledge and understanding The role of a phospholipid in a cell membrane provides the backbone to the whole lesson. A quick quiz round called family affair, challenges the students to use their knowledge of the structure of a triglyceride to identify the shared features in a phospholipid. This then allows the differences to be introduced, such as the presence of a phosphate group in place of the third fatty acid. Moving forwards, the students will learn that the two fatty acid tails are hydrophobic whilst the phosphate head is hydrophilic which leads into a key discussion point where the class has to consider how it is possible for the phospholipids to be arranged when both the inside and outside of a cell is an aqueous solution. The outcome of the discussion is the introduction of the bilayer which is critical for the lessons in topic 4 on the fluid mosaic model. The final part of the lesson explains how both facilitated diffusion and active transport mean that proteins are found floating in the cell membrane and this also helps to briefly prepare the students for upcoming topic 4 lessons.

This lesson describes the relationship between gross and net primary productivity and plant respiration and explains how to calculate NPP. The PowerPoint and accompanying resources have been designed to cover points 5.10 (i) and (ii) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification. Due to the fact that the productivity of plants is dependent on photosynthesis, a series of exam-style questions have been written into the lesson which challenge the students to explain how the structure of the leaf as well as the light-dependent and light-independent reactions are linked to GPP. All of the exam questions have displayed mark schemes which are included in the PowerPoint to allow students to immediately assess their understanding. A number of quick quiz competitions as well as guided discussion points are used to introduce the formulae to calculate NPP and N and to recognise the meaning of the components. Once again, this is immediately followed by the opportunity to apply their understanding to selected questions. As well as linking to photosynthesis from earlier in topic 5, this lesson has been specifically planned to challenge students on their understanding of ecosystem terminology from the start of the topic as well as preparing them for the next lesson on the efficiency of biomass and energy transfer

This lesson describes the steps in the emulsion test for lipids and then uses a range of tasks to challenge the students on their knowledge of topic 1.3. The engaging PowerPoint and accompanying resource are part of the last lesson in a series of 3 lessons which have been designed to cover the content of point 1.3 (lipids) of the AQA A-level Biology specification. The first part of the lesson describes the key steps in the emulsion test for lipids, and states the positive result for this test. There is a focus on the need to mix the sample with ethanol, which is a distinctive difference to the tests for reducing sugars and starch. The remainder of the lesson uses exam-style questions with mark schemes embedded in the PowerPoint, understanding checks, guided discussion points and quick quiz competitions to challenge the following specification points: The structure of a triglyceride The relationship between triglyceride property and function The hydrophilic and hydrophobic nature of the phospholipid The phospholipid bilayer of the cell membrane Cholesterol is also introduced so that students are prepared for this molecule when it is met in topic 2.3 (cell membranes)

This lesson explains the effects of temperature on the rate of enzyme activity and includes examples in plants, animals and microorganisms. The PowerPoint and the accompanying resource have been designed to cover point 5.16 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and this lesson has been specifically planned to tie in with a lesson in topic 2 where the roles and mechanism of action of enzymes were introduced. The lesson begins by challenging the students to recognise optimum as a key term from its 6 synonyms that are shown on the board. Time is taken to ensure that the students understand that the optimum temperature is the temperature at which the most enzyme-product complexes are produced per second and therefore the temperature at which the rate of an enzyme-controlled reaction works at its maximum. The optimum temperatures of DNA polymerase in humans and in a thermophilic bacteria and RUBISCO in a tomato plant are used to demonstrate how different enzymes have different optimum temperatures and the roles of the former in the PCR is briefly described to prepare students for this lesson in topic 6. Moving forwards, the next part of the lesson focuses on enzyme activity at temperatures below the optimum and at temperatures above the optimum. Students will understand that increasing the temperature increases the kinetic energy of the enzyme and substrate molecules, and this increases the likelihood of successful collisions and the production of enzyme-substrate and enzyme-product complexes. When considering the effect of increasing the temperature above the optimum, continual references are made to the previous lesson and the control of the shape of the active site by the tertiary structure. Students will be able to describe how the hydrogen and ionic bonds in the tertiary structure are broken by the vibrations associated with higher temperatures and are challenged to complete the graph to show how the rate of reaction decreases to 0 when the enzyme has denatured.

This fully-resourced lesson describes the process of contraction of skeletal muscle in terms of the sliding filament theory. The PowerPoint and accompanying resources have been designed to cover point 7.11 of the Edexcel International A-level Biology specification and includes descriptions of the role of actin, myosin, troponin, tropomyosin, calcium ions, ATP and ATPase. The lesson begins with a study of the structure of the thick and thin filaments. Students will recognise that the protruding heads of the myosin molecule are mobile and this enables this protein to bind to the binding sites when they are exposed on actin. This leads into the introduction of troponin and tropomyosin and key details about the binding of calcium to this complex is explained. Moving forwards, students are encouraged to discuss possible reasons that can explain how the sarcomere narrows during contraction when the filaments remain the same length. This main part of the lesson goes through the main steps of the sliding filament model of muscle contraction and the critical roles of the calcium ions and ATP are discussed. The final task of the lesson challenges the students to apply their knowledge by describing the immediate effect on muscle contraction when one of the elements doesn’t function correctly. This lesson has been written to tie in with the previous lesson on the structure of skeletal muscle fibre (point 7.10)

This lesson describes the role of the cardiovascular control centre in the medulla oblongata in the control of heart rate. The engaging and detailed PowerPoint and accompanying resources have been designed to cover the first part of point 7.13 (ii) of the Edexcel International A-level Biology specification and explains how this regulation enables the rapid delivery of oxygen and the removal of carbon dioxide. This lesson begins with a prior knowledge check where students have to identify and correct any errors in a passage about the conduction system of the heart. This allows the SAN to be recalled as this structure play an important role as the effector in this control system. Moving forwards, the three key parts of a control system are recalled as the next part of the lesson will specifically look at the range of sensory receptors, the coordination centre and the effector. Students are introduced to chemoreceptors and baroreceptors and time is taken to ensure that the understanding of the stimuli detected by these receptors is complete and that they recognise the result is the conduction of an impulse along a neurone to the brain. A quick quiz is used to introduce the medulla oblongata as the location of the cardiovascular centre. The communication between this centre and the SAN through the autonomic nervous system can be poorly understood so detailed explanations are provided and the sympathetic and parasympathetic divisions compared. The final task challenges the students to demonstrate and apply their understanding by writing a detailed description of the control and this task has been differentiated three ways to allow differing abilities to access the work

This lesson reminds students of the meaning of homeostasis and describes the how thermoregulation maintains the body in dynamic equilibrium during exercise. The PowerPoint has been designed to cover point 7.17 of the Edexcel International A-level Biology specification. Students were introduced to homeostasis at GCSE and this lesson has been written to build on that knowledge and to add the key detail needed at this level. Focusing on the three main parts of a homeostatic control system, the students will learn about the role of the internal and peripheral thermoreceptors, the thermoregulatory centre in the hypothalamus and the range of effectors which bring about the responses to restore optimum levels. The following responses are covered in this lesson: Vasodilation Increased sweating Body hairs In each case, time is taken to challenge students on their ability to make links to related topics such as the arterioles involved in the redistribution of blood and the high specific latent heat of vaporisation of water.

This fully-resourced lesson describes how selection pressures act on a gene pool and cause stabilising, directional and disruptive selection. The PowerPoint and accompanying resources have been designed to cover point 8.3 (i) of the Edexcel A-level Biology B specification which states that students should be able to identify each type of selection by its effect on different phenotypes. The lesson begins with an introduction to the mark, release, recapture method to calculate numbers of rabbits with different coloured fur in a particular habitat. This shows changes in numbers of the organisms and sketch graphs are then constructed to show these changes in the population size. A quick quiz competition is used to engage the students whilst introducing the names of the three main types of selection before a class discussion point encourages the students to recognise which specific type of selection is represented by the rabbits. Key terminology including intermediate and extreme phenotypes and selection pressure are used to emphasise their importance during explanations. A change in the environment of the habitat and a change in the numbers of the rabbits introduces directional selection before students will be given time to discuss and to predict the shape of the sketch graph for disruptive selection. Students are challenged to apply their knowledge in the final task of the lesson by choosing the correct type of selection when presented with details of a population and answer related questions.