This fully-resourced lesson describes the differences between continuous and discontinuous variation. The engaging PowerPoint and accompanying resources have been designed to cover point 17.1 (a) of the CIE A-level Biology specification but also acts as a revision of topic 16 as it challenges students on their knowledge of gene mutations and meiosis. The students begin the lesson by having to identify phenotype and species from their respective definitions so that a discussion can be encouraged where they will recognise that phenotypic variation within a species is due to both genetic and environmental factors. The main part of the the lesson focuses on these genetic factors, and describes how mutation and the events of meiosis contribute to this variation. A range of activities, which include exam-style questions and quick quiz rounds, are used to challenge the students on their knowledge and understanding of substitution mutations, deletions, insertions, the genetic code, crossing over and independent assortment. Moving forwards, the concept of multiple alleles is introduced and students will learn how the presence of more than 2 alleles at a locus increases the number of phenotypic variants. Another quick quiz round is used to introduce polygenic inheritance and the link is made between this inheritance of genes at a number of loci as an example of continuous variation. In line with the title of the lesson, the next task challenges them to recognise descriptions and examples which apply to the different types of variations. The final part of the lesson introduces a few examples where environmental factors affect phenotype, such as chlorosis in plants, so that students are prepared for the following lesson.

This lesson describes the relationship between the structure and function of the polysaccharides, starch and cellulose. The detailed PowerPoint and accompanying resource have been designed to cover point 4.3 of the Edexcel International A-level Biology specification and includes a focus on the role of the hydrogen bonds between the beta-glucose molecules in the formation of cellulose microfibrils. The structure of amylose and amylopectin was described during a lesson in topic 1, so the start of this lesson challenges the students on their recall of these details. They have to complete a comparison table for these two polysaccharides by identifying the monomer and type of glycosidic bonds that are found in each of the structures. Time is taken to explain how the greater resistance to digestion of amylose means that this carbohydrate is important for plant energy storage whereas the multiple chain ends in the branched amylopectin means that this polysaccharide can be hydrolysed quickly when energy is needed. The rest of the lesson describes the structure of cellulose and focuses on the link between the structure and the need for this polysaccharide to support the plant cell as well as the whole plant. Students will see how every other beta glucose monomer is rotated by 180 degrees and will learn that hydrogen bonds form between these molecules on the same chain as well as between adjacent chains in a cellulose microfibril. The lesson concludes with a quick quiz competition where the students have to compete to open a safe using a combination made up of key values associated with glycogen, starch and cellulose.

This engaging and detailed lesson looks at the roles of the Link reaction and the Krebs cycle as the stages of aerobic respiration which occur in the mitochondrial matrix. Both the PowerPoint and the accompanying resource have been designed to cover point 7.5 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification. The lesson begins with a challenge, where the students have to recall the details of glycolysis in order to form the word matrix. This introduces the key point that these two stages occur in this part of the mitochondria and time is taken to explain why the reactions occur in the matrix as opposed to the cytoplasm like glycolysis. Moving forwards, the Link reaction is covered in 5 detailed bullet points and students have to add the key information to these points using their prior knowledge as well as knowledge provided in terms of NAD. The students will recognise that this reaction occurs twice per molecule of glucose and a quick quiz competition is used to test their understanding of the numbers of the different products of this stage. This is just one of the range of methods that are used to check understanding and all answers are explained to allow students to assess their progress. The rest of the lesson focuses on the Krebs cycle. In line with the detail of the specification, students will understand how decarboxylation and dehydrogenation reactions result in the regeneration of the 4C compound. It is estimated that it will take about 2 hours of A-level teaching time to cover the detail of the lesson and therefore the detail of the specification point 7.5

This lesson describes the general structure of the 20 amino acids found in proteins and makes clear links to related topics such as genes. The PowerPoint has been designed to cover specification point 2.1.2 (k) of the OCR A-level Biology A course and provides a clear introduction to the following lesson on the formation of dipeptides and polypeptides. The lesson begins with a prior knowledge check, where the students have to use the 1st letters of 4 answers to uncover a key term. This 4-letter key term is gene and the lesson begins with this word because it is important for students to understand that these sequences of bases on DNA determine the specific sequence of amino acids in a polypeptide. Moving forwards, students are given discussion time to work out that there are 64 different DNA triplets and will learn that these encode for the 20 amino acids that are common to all organisms. The main task of the lesson is an observational one, where students are given time to study the displayed formula of 4 amino acids. They are not allowed to draw anything during this time but will be challenged with 3 multiple choice questions at the end. This task has been designed to allow the students to visualise how the 20 amino acids share common features in an amine and an acid group. A quick quiz round introduces the R group and time is taken to explain how the structure of this side chain is the only structural difference. Students will be introduced to the existence of hydrophobic, hydrophilic, acidic and basic R groups so that they are able to apply this knowledge in future lessons where structure and shape is considered. Some time is also given to look at cysteine in greater detail due to the presence of sulfur atoms and once again a link is made to disulfide bridges for upcoming lessons. The lesson concludes with one more quiz round called LINK TO THE FUTURE where the students will see the roles played by amino acids in the later part of the course such as translation and in the formation of dipeptides.

This detailed lesson uses haemoglobin and collagen to describe the relationship between the structure and functions of globular and fibrous proteins. The engaging PowerPoint and accompanying worksheet have been primarily designed to cover specification point 2.3 © of the CIE International A-level Biology course but due to the detailed coverage of haemoglobin, this resource could also be used when teaching a lesson on the role of this protein in topic 8. The first part of the lesson looks at the structure of haemoglobin, and describes how the presence of an iron-containing haem group on the outside of the 4 polypeptide chains explains its ability to form oxyhaemoglobin. Moving forwards, the importance of the solubility of this protein is considered and related to the direction that the hydrophobic R groups point. At this point of the lesson, the students are challenged to construct a comparison table which can be filled in as the lesson progresses and as they are given more details of collagen. The section of the lesson concerning collagen begins with the introduction of its function in the artery wall so that students can recognise how fibrous proteins have roles associated with mechanical strength. Time is taken to discuss their solubility as well as the presence of repetitive amino acid sequences. The remainder of the lesson considers four more proteins and the final task challenges the students to use their completed table to write a summary passage comparing globular and fibrous proteins.

This fully-resourced lesson describes the beneficial, neutral and harmful effects of gene mutations on the primary structure of a polypeptide. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 6.1.1 (a) of the OCR A-level Biology A specification which states that students should be able to understand how substitutions, deletions and insertions change the base sequence and describe how this affects protein production and function. In order to understand how a change in the base sequence can affect the order of the amino acids, students must be confident in their understanding and application of protein synthesis which was covered in module 2.1.3. Therefore, the start of the lesson focuses on transcription and translation and students are guided through the use of the codon table to identify amino acids. Moving forwards, a task called known as THE WALL is used to introduce to the names of three types of gene mutation whilst challenging the students to recognise terms which are associated with the genetic code and were met back in 2.1.3. The main focus of the lesson is base substitutions and how these mutations may or may not cause a change to the amino acid sequence. The students are challenged to use their knowledge of the degenerate nature of the genetic code to explain how a silent mutation can result. The rest of the lesson looks at base deletions and base insertions and students are introduced to the idea of a frameshift mutation. One particular task challenges the students to evaluate the statement that base deletions have a bigger impact on primary structure than base substitutions. This is a differentiated task and they have to compare the fact that the reading frame is shifted by a deletion against the change in a single base by a substitution

This lesson introduces monomers, polymers, condensation and hydrolysis reactions and chemical bonds to prepare students for the rest of topic 1 (biological molecules). The PowerPoint and accompanying worksheet cover point 1.1 of the AQA A-level Biology course, and as this is likely to be the very first lesson that the students encounter, the range of engaging tasks have been specifically designed to increase the likelihood of the key points and fundamentals being retained. Monomers were previously met at GCSE and so the beginning of the lesson focuses on the recall of the meaning of this key term before the first in a series of quiz rounds is used to introduce nucleotides, amino acids and monosaccharides as a few of the examples that will be met in this topic. Dipeptides and disaccharides are introduced as structures containing 2 amino acids or sugars respectively and this is used to initiate a discussion about how monomers need to be linked together even more times to make the larger chains known as polymers. At this point in the lesson, the students are given the definition of a condensation reaction and then challenged to identify where the molecule of water is eliminated from when two molecules of glucose join. A series of important prefixes and suffixes are then provided and students use these to predict the name of the reaction which has the opposite effect to a condensation reaction - a hydrolysis reaction. Links to upcoming lessons are made throughout the PowerPoint to encourage students to begin to recognise the importance of making connections between topics.

This lesson describes the mass flow hypothesis for the mechanism of translocation in plants and includes details of active loading at the source. Both the detailed PowerPoint and accompanying resources have been designed to cover the 4th part of point 3.4.2 of the AQA A-level Biology specification. The lesson begins by challenging the students to recognise the key term translocation when it is partially revealed and then the rest of the lesson focuses on getting them to understand how this mechanism involves the mass flow of assimilates down the hydrostatic pressure gradient from the source to the sink. It has been written to tie in with an earlier lesson in topic 3.4.2 where the structure of the phloem tissue was initially introduced and the students are continually challenged on this prior knowledge. A step-by-step guide is used to describe how sucrose is loaded into the phloem at the source by the companion cells. Time is taken to discuss key details such as the proton pumping to create the proton gradient and the subsequent movement back into the cells by facilitated diffusion using co-transporter proteins. Students will learn that the hydrostatic pressure at the source is high, due to the presence of the water and sucrose as cell sap, and that this difference when compared to the lower pressure at the sink leads to the movement along the phloem. A number of quick quiz rounds are included in the lesson to maintain engagement and to introduce key terms and the lesson concludes with a game of SOURCE or SINK as students have to identify whether a particular plant structure is one or the other (or both)

This fully-resourced lesson describes the differences between bacteriostatic and bactericidal antibiotics. The engaging PowerPoint and accompanying resources have been designed to cover point 6.13 of the Edexcel International A-level Biology specification but also makes continual links to earlier lessons in topic 6 as well as related topics from the previous year such as protein synthesis from topic 2 The lesson begins by challenging the students to use their knowledge of the previous topic 6 lessons to identify the suffixes cidal and static. Students will learn that when the prefix is added, these form the full names of two types of antibiotics. Their understanding of terminology is tested further as they have to recognise that Polymyxin B is an example of a bactericidal antibiotic as its actions would result in the death of the bacterial cell. Tetracycline is used as the example of a bacteriostatic antibiotic and students will discover that its prevention of the binding of tRNA that inhibits protein synthesis and this reduction and stopping of growth and reproduction is synonymous with these drugs. Students are challenged on their knowledge of translation and will also be given time for a class discussion to understand that these antibiotics encourage the body’s immune system to overcome the pathogen in natural, active immunity. The final part of the lesson uses a quick quiz competition and a series of exam-style questions to ensure that students can recognise the different antibiotics from descriptions.

This revision resource has been designed to include a range of activities that will engage the students whilst they assess their understanding of the content of topic B8 (Gas exchange and respiration) of the CIE IGCSE Combined Science specification for examination in June and November 2020 and 2021. Exam questions, quick tasks and quiz competitions such as “The BIG REVEAL” will challenge the students on their recall of the content as well as their ability to apply this knowledge. The lesson was written to cover as much of the content as possible, but the following topics have received particular attention: The role of cilia, goblet cells and mucus in the trachea and bronchi The effects of the chemicals in tobacco smoke on gas exchange Efficient gas exchange at the alveoli The composition of inhaled and exhaled air Aerobic respiration as the chemical reaction that releases energy The uses of energy in the human body This resource contains an engaging PowerPoint (54 slides) and associated worksheets and is ideal for use at the end of this topic or in the lead up to mocks or the actual terminal exams

This lesson has been designed to provide students with the opportunity to assess their understanding of topic 1 of the AQA A-level biology specification. Included in the lesson is an assessment consisting of 20 multiple choice questions and a PowerPoint containing the answers. The PowerPoint also contains explanations and key points related to the specification, as well as additional knowledge checks to challenge the content which isn’t directly covered by the 20 questions. There are also slides titled “Link to the future” where content is linked to upcoming lessons from topics 2 - 8. This lesson has been planned to be used at the end of topic 1, and/or in the build up to the final A-level assessments. Multiple-choice assessments for the other 7 topics are also uploaded.

This fully-resourced lesson describes the processes of active transport, endocytosis and exocytosis and explains the need for ATP. The PowerPoint and accompanying worksheets have been designed to cover the second part of point 4.2 (a) of the CIE International A-level Biology specification. The first part of 4.2 (a), concerning simple and facilitated diffusion, was covered in the previous lesson. The start of the lesson challenges the students to use their prior knowledge of biological molecules to come up with the abbreviation ATP and they will learn that this is a phosphorylated nucleotide that contains adenine, ribose and three phosphate groups. Students may not have known this as the energy currency from GCSE so time is taken to explain that this molecule must be broken down to release energy and students are challenged to recall which type of reaction will be involved and to predict the products of such a reaction. This hydrolysis of ATP can be coupled to energy-requiring reactions within the cell and the rest of the lesson focuses on the use of this energy for active transport, endocytosis and exocytosis. Students are challenged to answer a series of questions which compare active transport against the forms of passive transport and to use data from a bar chart to support this form of transport. In answering these questions they will discover that carrier proteins are specific to certain molecules and time is taken to look at the exact mechanism of these transmembrane proteins. A quick quiz round introduces endocytosis and the students will see how vesicles are involved along with the energy source of ATP to move large substances in or out of the cell. The lesson concludes with a link to a future topic as the students are shown how exocytosis is involved in a synapse.

This fully-resourced lesson uses the lac operon as an example to describe how gene expression is regulated and controls cell processes and structures. The detailed PowerPoint and accompanying resources have been designed to cover the details of specification point 3.12 of the Pearson Edexcel A-level Biology A 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 2, 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. The 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. The final section of the lesson looks at one further example with oestrogen and the ER receptor.

This revision lesson provides students with the opportunity to assess their understanding of the AQA A-level biology topic 6 content. The lesson includes a multiple-choice assessment of 20 questions which have been written to challenge the content of topic 6 (Organisms respond to changes in their internal and external environments) and a PowerPoint where the answers are revealed, along with explanations and key points related directly to the specification. The PowerPoint also includes other questions about topic 6 that aren’t directly challenged in the 20 questions, as well as prior knowledge checks to encourage the students to make links to content from topics 1 - 5. This resource has been designed to be used at the end of the teaching of topic 6 and/or in the build up to the final A-level assessments. Lessons challenging content from the other 7 specification topics are also uploaded.

This revision lesson provides students with the opportunity to assess their understanding of inheritance (topic 16). 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 16 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 - 15. This lesson has been designed to be used at the end of topic 16, 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 biological molecules (topic 2). 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 2 of the CIE A-level biology specification (2025 - 2027 update) that isn’t directly covered by the 10 questions. This lesson has been designed to be used at the end of topic 2, and in the build up to mocks and the final A-level assessments.

This engaging lesson describes the relationship between the structure and functions of a phopholipid, focusing on the role performed in membranes. The PowerPoint has been designed to cover specification point 2.2 (g) of the CIE International A-level Biology specification and includes constant references to the previous lesson on the structure and function of triglycerides. 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 phospholipid bilayer which is critical for the lesson in topic 4 on the fluid mosaic model. The final part of the lesson describes how proteins found floating in the cell membrane allow both facilitated diffusion and active transport to occur and this also helps to begin the preparations for the upcoming lessons.

This lesson describes the biuret test for proteins and then uses a range of activities to challenge the students on their knowledge of topic 1.4.1. The engaging PowerPoint and accompanying resources are part of the last lesson in a series of 3 lessons which have been designed to cover the content detailed in topic 1.4.1 (General properties of proteins) of the AQA A-level Biology specification. The first section of the lesson describes the steps in the biuret test and challenges the students on their recall of the reducing sugars and starch tests from topic 1.2 to recognise that this is a qualitative test that begins with the sample being in solution. The students will learn that the addition of sodium hydroxide and then copper sulphate will result in a colour change from light blue to lilac if a protein is present. The remainder of the lesson uses exam-style questions with displayed mark schemes, understanding checks and quick quiz competitions to engage and motivate the students whilst they assess their understanding of this topic. The following concepts are tested during this lesson: The general structure of an amino acid The formation of dipeptides and polypeptides through condensation reactions The primary, secondary, tertiary and quaternary structure of a protein Biological examples of proteins and their specific actions (e.g. antibodies, enzymes, peptide hormones)

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 molecular evidence can be used to reveal similarities between closely-related organisms. The PowerPoint and accompanying resources have been primarily designed to cover point 17.3 (b) of the CIE A-level Biology specification and focus on the comparison of protein structure and mitochondrial DNA but can also be used as a revision of related topics that include protein synthesis and gene mutations. The lesson begins with the introduction of convergent evolution, a process where organisms independently evolve to have similar features due to theeir habitation of similar environments. This allows the importance of molecular evidence to be considered to ensure that organisms which are closely related (in terms of evolution) are recognised. The comparison of the primary structure of a protein involved in respiration (cytochrome c) is used to demonstrate how protein sequence data can be useful. At this point, a series of exam-style questions are used to challenge the students on their knowledge of protein synthesis and gene mutations from topics 6 and 16. The remainder of the lesson considers the use of mitochondrial DNA and a study of the mtDNA genomes of 51 gibbons demonstrates how this can provide evidence of relationships, even in organisms that show high taxonomic diversity like these lesser apes.