This engaging REVISION LESSON has been designed to cover the content of topic 13 (Photosynthesis) of the CIE International A-level Biology specification. Filled with a wide range of activities, that include exam questions with explanations, quick tasks and quiz competitions, the students will be motivated whilst they assess their ability to apply their knowledge. Due to the obvious importance of this reaction, assessment questions are extremely common and so a deep understanding of this topic is key to success and the lesson has been designed to cover the important ideas. The following sub-topics have received particular attention in this lesson: Photophosphorylation An outline of cyclic and non-cyclic photophosphorylation Photolysis of water The light dependent reaction The structure of the chloroplast and the site of the different reactions The Calvin cycle The limiting factors of photosynthesis Investigating the effect of light intensity using DCPIP as a redox indicator and a Hill suspension The effect of temperature on the rate There is a focus on terminology throughout the lesson so that students are comfortable with the terms that will be encountered in exam questions. Revision lessons on the other topics of the specification are uploaded so please take a moment to look at those too

This detailed and engaging REVISION LESSON has been written to cover the content of topic 4 (Cell membranes and transport) of the CIE International A-level Biology specification. The lesson consists of a PowerPoint that contains exam questions, differentiated tasks and quiz competitions and is accompanied by worksheets with further activities. The competitions act to engage the students whilst they assess their understanding of the content and challenges their ability to apply this knowledge to potentially unfamiliar situations. The lesson was designed to cover as much of the specification content as possible but the following sub-topics have received particular attention: Active transport and its applications in animals and plants Facilitated diffusion and the use of channel and carrier proteins The factors that affect diffusion as demonstrated by gas exchange at the alveoli Exocytosis Water potential and the movement of water by osmosis The effect of solutions of different water potentials on animal and plant tissue The fluid mosaic model The plasma cell membrane and the function of its components As well as covering the current topic, the design of this lesson has been conscious to include future topics. For example, a cholinergic synapse was used to challenge the students to spot examples of facilitated diffusion, simple diffusion, active transport and exocytosis. Revision lessons for the other 18 topics are uploaded on TES or are in the process of being uploaded.

This fully-resourced lesson guides students through the use of the Hardy-Weinberg equation to calculate the frequency of alleles, genotypes and phenotypes in a population. Both the detailed PowerPoint and differentiated practice questions on a worksheet have been designed to cover the 2nd part of point 7.2 of the AQA A-level Biology specification which expects students to be able to use this mathematical model The lesson begins by looking at the equation and ensuring that students understand the meaning of each of the terms. The recessive condition, cystic fibrosis, is used as an example so that students can start to apply their knowledge and assess whether they understand which genotypes go with which term. Moving forwards, a step-by-step guide is used to show students how to answer a question. Tips are given during the guide so that common misconceptions and mistakes are addressed immediately. The rest of the lesson gives students the opportunity to apply their knowledge to a set of 3 questions, which have been differentiated so that all abilities are able to access the work and be challenged.

This fully-resourced lesson explores sex-linkage and specifically the inheritance of sex-linked diseases in humans and then challenges the students to apply their knowledge to examples in other animals. The detailed PowerPoint and associated differentiated resources have been designed to cover the part of point 16.2 (b) of the CIE International A-level Biology specification which states that students should be able to use genetic diagrams to solve problems involving sex-linkage. Key genetic terminology is used throughout and the lesson begins with a check on their ability to identify the definition of homologous chromosomes. Students will recall that the sex chromosomes are not fully homologous and that the smaller Y chromosome lacks some of the genes that are found on the X. This leads into one of the numerous discussion points, where students are encouraged to consider whether females or males are more likely to suffer from sex-linked diseases. In terms of humans, the lesson focuses on haemophilia and red-green colour blindness and a step-by-step guide is used to demonstrate how these specific genetic diagrams should be constructed and how the phenotypes should then be interpreted. The final tasks of the lesson challenge the students to carry out a dihybrid cross that involves a sex-linked disease and an autosomal disease before applying their knowledge to a question about chickens and how the rate of feather production in chicks can be used to determine gender. All of the tasks are differentiated so that students of differing abilities can access the work and all exam questions have fully-explained, visual markschemes to allow them to assess their progress and address any misconception

This fully-resourced lesson focuses on the role of meiosis in ensuring genetic variation through the production of non-identical gametes. The detailed PowerPoint and accompanying resource have been designed to cover point 3.9 of the Pearson Edexcel A-level Biology (Salters Nuffield) specification which states that students should be able to describe how crossing over and independent assortment result in genetically unidentical daughter cells. 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.

This lesson focuses on the nature of the genetic code and specifically focuses on the degenerate nature to make a link to gene mutations which is covered later in topic 2. The PowerPoint has been designed to cover point 2.7 of the Pearson Edexcel A-level Biology (Salters Nuffield) specification which states that students should understand how the descriptive terms triplet code, degenerate and non-overlapping relate to the genetic code. The lesson begins by introducing the terms near universal and non-overlapping in addition to degenerate. A quick quiz competition is used to generate the number 20 so that the students can learn that there are 20 proteinogenic amino acids in the genetic code. This leads into a challenge, where they have to use their prior knowledge of DNA to calculate the number of different DNA triplets (64) and the mismatch in number is then discussed and related back to the lesson topic. Moving forwards, substitutions and deletions are briefly introduced so that they can see how although one substitution can change the primary structure, another will change the codon but not the encoded amino acid. The lesson concludes with a brief look at the non-overlapping nature of the code so that the impact of a base deletion can be understood when covered in greater detail with cystic fibrosis

This fully-resourced lesson covers the meaning of the 9 genetic terms that are detailed in point 2.13 (i) of the Pearson Edexcel A-level Biology (Salters Nuffield) specification as well as four other key terms which will need to be used later in topic 2, 3 and 8. In the following lessons, students are expected to be able to demonstrate and apply their knowledge and understanding of genetic diagrams and phenotypic ratios to show patterns of inheritance and this is only possible with a clear understanding of the genetic terminology that will be used in related exam questions. As some of these terms were met at GCSE, this lesson has been designed to 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 act as an understanding check. The 13 terms are genome, gene, chromosome, gene locus, homologous chromosomes, alleles, dominant, recessive, genotype, phenotype, homozygotes and heterozygotes

This is a fully-resourced lesson which looks at the inheritance of genes that are carried on the sex chromosomes in sex-linkage. Students will explore sex-linked diseases in humans and then are challenged to apply their knowledge to examples in other animals. The detailed PowerPoint and associated resources have been designed to cover the second part of point 3.8 (ii) of the Pearson Edexcel A-level Biology (Salters Nuffield) specification which states that students should understand sex-linkage. Key genetic terminology is used throughout and the lesson begins with a check on their ability to identify the definition of homologous chromosomes. Students will recall that the sex chromosomes are not fully homologous and that the smaller Y chromosome lacks some of the genes that are found on the X. This leads into one of the numerous discussion points, where students are encouraged to consider whether females or males are more likely to suffer from sex-linked diseases. In terms of humans, the lesson focuses on haemophilia and red-green colour blindness and a step-by-step guide is used to demonstrate how these specific genetic diagrams should be constructed and how the phenotypes should then be interpreted. The final tasks of the lesson challenge the students to apply their knowledge to a question about chickens and how the rate of feather production in chicks can be used to determine gender.

This fully-resourced lesson looks at how errors in DNA replication can give rise to gene mutations and then links to an earlier topic by exploring how these base changes can affect the primary structure of a polypeptide. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 2.12 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and constantly refers back to points 2.7, 2.8 and 2.9 which detail the genetic code, genes and the structure of proteins. 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 taught in 2.6. 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 quick quiz competition is used to introduce 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 in the previous lesson. 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 fully-resourced lesson looks at the series of oxidation-reduction reactions that form the Krebs cycle and focuses on the products in terms of reduced NAD, FAD and ATP. The engaging PowerPoint and accompanying resource have both been designed to cover the fifth part of point 5.2 of the AQA A-level Biology specification. The lesson begins with a version of the Impossible game where students have to spot the connection between 8 of the 9 terms and will ultimately learn that this next stage is called the Krebs cycle. The main part of the lesson challenges the students to use descriptions of the main steps of the cycle to continue their diagram of the reactions. Students are continually exposed to key terminology such as decarboxylation and dehydrogenation and they will learn where carbon dioxide is lost and reduced NAD and FAD are generated. They will also recognise that ATP is synthesised by substrate level phosphorylation. The final task challenges them to apply their knowledge of the cycle to work out the numbers of the different products and to calculate the number of ATP that must be produced in the next stage This lesson has been designed to tie in with the other uploaded lessons on glycolysis, anaerobic respiration, the Link reaction and oxidative phosphorylation.

This detailed lesson introduces the four stages of aerobic respiration and looks at the relationship between structure and function of the mitochondrion. The engaging PowerPoint and accompanying resource have been designed to cover points 12.2 (a) and (i) of the CIE International A-level Biology specification which states that students should be able to demonstrate and apply an understanding of the inner and outer mitochondrial membranes, cristae, matrix and mitochondrial DNA. The lesson begins with an introduction to glycolysis and students will learn how this first stage of aerobic respiration is also the first stage when oxygen isn’t present. A version of “GUESS WHO” challenges students to use a series of structural clues to whittle the 6 organelles down to just the mitochondrion so that they can learn how the other three stages take place inside this organelle. Moving forwards, the key components of the organelle are identified on a diagram. Students are introduced to the stages of respiration so that they can make a link to the parts of the cell and the mitochondria where each stage occurs. Students will learn that the presence of decarboxylase and dehydrogenase enzymes in the matrix along with coenzymes and oxaloacetate allows the Link reaction and the Krebs cycle to run. Finally, time is taken to introduce the electron transport chain and the enzyme, ATP synthase, so that students can begin to understand how the flow of protons across the inner membrane results in the production of ATP.

This clear and concise lesson looks at the role of the link reaction in the conversion of pyruvate to acetyl coenzyme A which will then enter the Krebs cycle. The PowerPoint has been designed to cover point 12.2 © of the CIE International A-level Biology specification which states that students should be able to explain that this conversion occurs in the matrix when oxygen is present 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 this stage occurs 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. This lesson has been written to tie in with the other uploaded lessons on glycolysis and the Krebs cycle and oxidative phosphorylation.

This fully-resourced lesson explores how glucose as well as the other respiratory substrates, such as lipids and proteins, can enter the respiratory pathway and therefore can be respired to produce molecules of ATP. The engaging PowerPoint and accompanying resources have been designed to cover points 12.1 (f) and (g) of the CIE International A-level Biology specification which states that students should be able to explain the relative energy values of carbohydrates, lipids and proteins and be able to determine respiratory quotients from equations. This lesson has been written to challenge current understanding as well as introduce details of glycolysis, the link reaction and Krebs cycle as these stages have yet to be covered fully. Students will learn that lipids and proteins can be used as respiratory substrates and will recognise the different ways that they enter the respiratory pathway. A quick quiz competition is used to introduce the relative energy value for carbohydrates and students are challenged to predict how the values for lipids and proteins will compare. As a result, students will recognise that a greater number of hydrogen atoms results in a greater availability of protons to form the proton gradient to fuel the production of ATP. The rest of the lesson focuses on the calculation of the respiratory quotient and time is taken to look at how the result can be interpreted to determine which substrates were respired.

This fully-resourced lesson explores how the structure of arteries, veins and capillaries relates to their functions. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 1.3 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification. This lesson has been written to build on any prior knowledge from GCSE or earlier in this topic to enable students to fully understand why a particular type of blood vessel has particular features. Students will be able to make the connection between the narrow lumen and elastic tissue in the walls of arteries and the need to maintain the high pressure of the blood. A quick version of the GUESS WHO game is used to introduce smooth muscle and collagen in the tunica media and externa and again the reason for their presence is explored and explained. Moving forwards, the lesson considers the structure of the veins and students are challenged to explain how the differences to those observed in arteries is due to the lower blood pressure found in these vessels. The final part of the lesson looks at the role of the capillaries in exchange. Links are made to diffusion to ensure that students can explain how the red blood cells pressing against the endothelium results in a short diffusion distance. It is estimated that it will take about 2 hours of allocated A-level Biology teaching time to cover the detail included in this lesson

This detailed lesson describes and explains the blood pressure changes that occur during systole and diastole of the cardiac cycle. The PowerPoint and accompanying resource have been designed to cover point 8.2 © of the CIE International A-level Biology specification. The start of the lesson introduces the cardiac cycle as well as the key term systole, so that students can immediately recognise that the three stages of the cycle are atrial and ventricular systole followed by diastole. Students are challenged on their prior knowledge of the structure of the heart as they have to name and state the function of an atrioventricular and semi-lunar valve from an internal diagram. This leads into the key point that pressure changes in the chambers and the major arteries results in the opening and closing of these sets of valves. Students are given a description of the pressure change that results in the opening of the AV valves and shown where this would be found on the graph detailing the pressure changes of the cardiac cycle. They then have to use this as a guide to write descriptions for the closing of the AV valve and the opening and closing of the semi-lunar valves and to locate these on the graph. By providing the students with this graph, the rest of the lesson can focus on explaining how these changes come about. Students have to use their current and prior knowledge of the chambers and blood vessels to write 4 descriptions that cover the cardiac cycle. The final part of the lesson covers the changes in the volume of the ventricle. This lesson has been written to tie in with the other uploaded lessons on the heart as detailed in topic 8.2

This lesson focuses on the structure of RNA and specifically the similarities and differences between this nucleic acid and DNA. The engaging and detailed PowerPoint and accompanying resource have been designed to cover the second part of point 6.1 (b) of the CIE International A-level Biology specification which states that students should be able to describe the structure of this nucleic acid. Students were introduced to the detailed structure of a nucleotide and DNA in previous lessons, so this lesson is written to tie in with those and continuously challenge prior knowledge as well as the understanding of the current topic. The lesson begins with the introduction of RNA as a member of the family of nucleic acids and this enables students to recognise that this polynuclotide shares a number of structural features that were previously seen in DNA. A quiz round called “A FAMILY AFFAIR” is used to challenge their knowledge of DNA to recognise those features that are also found on RNA such as the chain of linked nucleotides, pentose sugars, nitrogenous bases and phosphodiester bonds. The next task pushes them to consider features that have not been mentioned and therefore are differences as they answer a structured exam-style question on how RNA differs from DNA. Students will learn that RNA is shorter than DNA and this leads into the final part of the lesson where mRNA and tRNA are introduced and again they are challenged to use the new information explain the difference in size. Brief details of transcription and then translation are provided so that students are prepared for the upcoming lessons on protein synthesis

This fully-resourced lesson looks at the structure of genes and explores their role as a base sequence on DNA that codes for the amino acid sequence of a polypeptide. Both the PowerPoint and accompanying resource have been designed to cover point 6.2 (a) of the CIE International A-level Biology specification which states that students should understand how a gene codes for a polypeptide. The lesson begins with a prior knowledge check as the students have to recognise the key term chromosome from a description involving DNA and histones. This allows genes, as sections of a chromosome, to be introduced and the first of a number of quiz rounds is then used to get the students to meet the term locus so that they can understand how each gene has a specific location on a chromosome. Whenever possible, opportunities are taken to make links to the other parts of the CIE specification and this is utilised here as students are reminded that alternative versions of a gene (alleles) can be found at the locus. Moving forwards, students will learn that 3 DNA bases is a triplet and that each triplet codes for a specific amino acid. At this point, the genetic code is introduced and students are challenged to explain how the code contains 64 different triplets. By comparing this number against the number of different amino acids in proteins, students will see how each amino acid is encoded for by more than one triplet and how this explains the degenerate nature of the genetic code which forms a link to an upcoming lesson on gene mutations.

This detailed lesson describes the role of the mRNA, tRNA, amino acids and the ribosome during the second stage of protein synthesis - translation. Both the PowerPoint and accompanying resources have been designed to cover the third part of point 4.2 of the AQA A-level Biology specification and ties in with the previous lessons in this topic on RNA and transcription. Translation is a topic which is often poorly understood and so this lesson has been written to enable the students to understand how to answer the different types of questions by knowing and including the key details of the structures involved. 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, the genetic code 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 that consists of this considerable 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 through the lesson, their confidence to answer this type 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 learnt to answer some questions which involve the genetic code and the mRNA codon table.