This lesson has been written to cover the part of specification point 5.1.2 © of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply an understanding of the process of selective reabsorption. It has specifically been designed to build on the knowledge gained in the previous lessons on the structure of the nephron and ultrafiltration. The lesson begins by challenging the students to recall the substances that are found in the glomerular filtrate so that each of them can be considered over the course of the rest of the lesson. Moving forwards, the first of the numerous discussion points which are included in the lesson is used to get students to predict the component of the filtrate which won’t be found in the urine when they are presented with pie charts from each of these situations. Upon learning that glucose is 100% reabsorbed, along with most of the ions and some of the water, the rest of the lesson focuses on describing the relationship between the structure of the PCT and the function of selective reabsorption. Again, this section begins by encouraging the students to discuss and to predict which structures they would expect to find in a section of the kidney if the function is to reabsorb. They are given the chance to see the structure (as shown in the cover image) before each feature is broken down to explain its importance. Time is taken to look at the role of the cotransporter proteins to explain how this allows glucose, along with sodium ions, to be reabsorbed from the lumen of the PCT into the epithelial cells. The final part of the lesson focuses on urea and how the concentration of this substance increases along the tubule as a result of the reabsorption of some of the water. This lesson has been designed for students studying on the OCR-A level Biology A course and ties in nicely with the other lessons from 5.1.2 (c and d) on the structure and function of the kidney

This lesson has been written to cover the detail of specification point 15.1 (f) of the CIE International A-level Biology specification which states that students should be able to explain the importance of myelination. A wide range of activities have been written into this resource to maintain the motivation of the students whilst ensuring that the detail is covered in depth. Interspersed with the activities are understanding checks and prior knowledge checks to allow the students to not only assess their understanding of the current topic but also challenge themselves to make links to earlier topics such as the movement of ions across membranes and biological molecules. Time at the end of the lesson is also given to future knowledge such as the involvement of autonomic motor neurones in the stimulation of involuntary muscles. Over the course of the lesson, students consider the structure of the myelin sheath and specifically how the insulation is not complete all the way along which leaves gaps known as the nodes of Ranvier which allow the entry and exit of ions. Saltatory conduction is poorly explained by a lot of students so time is taken to look at the way that the action potential jumps between the nodes and this is explained further by reference to local currents. The rest of the lesson focuses on the other two factors which are axon diameter and temperature and students are challenged to discover these two by focusing on the vampire squid. This lesson has been designed for students studying the CIE International A-level Biology course and the other part of this specification point which covers the refractory period was explained in the previous lesson on the transmission of the action potential

This fully-resourced lesson is highly detailed and covers all of specification points 14.1 (h, i and j) of the CIE International A-level Biology specification which states that students should be able to describe how blood glucose concentration is regulated using negative feedback mechanisms that release insulin or glucagon and outline the role of cyclic AMP. A wide range of activities will maintain motivation and engagement whilst the content is covered in detail to enable the students to explain how the receptors in the pancreas detect the concentration change and how the hormones attaching to receptor sites on the liver triggers a series of events in this effector organ. This is a topic which has a huge amount of difficult terminology so time is taken to look at all of the key words, especially those which begin with the letter G so students are able to use them accurately in the correct context. The final part of the lesson looks at the role of the secondary messenger, cyclic AMP, and describes how this is involved when glucagon and adrenaline attach to receptors on the liver. The action of adrenaline is also considered and linked to the breakdown of glycogen to glucose during glycogenolysis. This lesson has been written for students studying on the CIE International A-level Biology course and ties in with the other uploaded lessons which cover the content of topic 14.1 (Homeostasis in mammals)

This lesson focuses on the use and explanation of key genetic terms which will support students in their understanding of the topic 16 (inherited change) of the CIE International A-level Biology specification. In this topic, students are expected to use genetic diagrams to solve problems 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 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 act as an understanding check. 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

This fully-resourced lesson explores the contributions of the chromosome mutations that arise during meiosis to genetic variation. The engaging PowerPoint and accompanying worksheets have been designed and written to cover the part of point 4.3 of the AQA A-level Biology specification which states that students should be able to describe how mutations in the numbers of chromosomes can arise spontaneously and significantly contribute to evolution. Over the course of the lesson, students will encounter a number of chromosome mutations but the main focus is chromosome non-disjunction and they will learn that this can result in Down, Turner’s and Klinefelter’s syndromes. Students are guided through a description of the formation of gametes and zygotes with abnormal numbers of chromosomes before being challenged to describe the formation of a zygote with Turner’s syndrome. The key aspects of meiosis, which are taught in a future lesson, are introduced and related to the lead up to the change in chromosome number. Inversion, translocation, duplication and deletion are also introduced and links are made to other topics such as regulatory sequences and gene expression.

This fully-resourced lesson guides students through the use of the Hardy-Weinberg equation to see whether a change in allele frequency is occurring in a population over time. The detailed PowerPoint and differentiated practice questions worksheets have been designed to cover point 4.5 (i) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification which expects students to be able to use this mathematical equation 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 highly detailed and engaging lesson which explains how a nerve impulse (action potential) is conducted along an axon). The PowerPoint and accompanying resources have been designed to cover point 8.3 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification which states that students should be able to describe how the changes in the membrane permeability to sodium and potassium ions results in conduction. This topic is commonly assessed in the terminal exams so a lot of time has been taken to design this resource to include a wide range of activities that motivate the students whilst ensuring that the content is covered in the depth of detail that will allow them to have a real understanding. Interspersed within the activities are understanding checks and prior knowledge checks to enable the students to not only assess their progress against the current topic but also to challenge themselves on the links to earlier topics such as methods of movements across cell membranes and saltatory conduction. There are also a number of quiz competitions which are used to introduce key terms and values in a fun and memorable way and discussion points to encourage the students to consider why a particular process or mechanism occurs. Over the course of the lesson, the students will learn and discover how the movement of ions across the membrane causes the membrane potential to change. They will see how the resting potential is maintained through the use of the sodium/potassium pump and potassium ion leakage. There is a real focus on depolarisation to allow students to understand how generator potentials can combine and if the resulting depolarisation then exceeds the threshold potential, a full depolarisation will occur. At this point in the lesson students will discover how the all or nothing response explains that action potentials have the same magnitude and that instead a stronger stimulus is linked to an increase in the frequency of the transmission. The rest of the lesson challenges the students to apply their knowledge to explain how repolarisation and hyperpolarisation result and to suggest advantages of the refractory period for nerve cells.

This engaging lesson looks at the myogenic nature of cardiac muscle and explores the roles of the SAN, AVN, Bundle of His and Purkyne fibres in the normal electrical activity of the heart. The PowerPoint and accompanying resources have been designed to cover the points 7.8 (i & ii) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification. The lesson begins with the introduction of the SAN as the natural pacemaker and then time is given to study each step of the conduction of the impulse as it spreads away from the myogenic tissue in a wave of excitation. The lesson has been written to make clear links to the cardiac cycle and the structure of the heart and students are challenged on their knowledge of this system from topic 1. Moving forwards, students are encouraged to consider why a delay would occur at the AVN and then they will learn that the impulse is conducted along the Bundle of His to the apex so that the contraction of the ventricles can happen from the bottom upwards. The structure of the cardiac muscle cells is discussed and the final task of the lesson challenges the students to describe the conducting tissue, with an emphasis on the use of key terminology Due to the detailed nature of this lesson, it is estimated that it will take about 2 hours of A-level teaching time to cover the two specification points

This engaging lesson explores the roles of the SAN, AVN, Bundle of His and Purkyne fibres in the transmission of the wave of excitation through the heart. The PowerPoint and accompanying resources have been designed to cover the first part of point 6.1.3 of the AQA A-level Biology specification which states that students should be able to describe the myogenic stimulation of the heart and the subsequent wave of electrical activity. The lesson begins with the introduction of the SAN as the natural pacemaker and then time is given to study each step of the conduction of the impulse as it spreads away from the myogenic tissue in a wave of excitation. The lesson has been written to make clear links to the cardiac cycle and the structure of the heart and students are challenged on their knowledge of this system from topic 3. Moving forwards, students are encouraged to consider why a delay would occur at the AVN and then they will learn that the impulse is conducted along the Bundle of His to the apex so that the contraction of the ventricles can happen from the bottom upwards. The structure of the cardiac muscle cells is discussed and the final task of the lesson challenges the students to describe the conducting tissue, with an emphasis on the use of key terminology

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 clear and concise lesson looks at the calculation of cardiac output as the product of stroke volume and heart rate. This engaging PowerPoint and accompanying resource have both been designed to cover point 7.9 (i) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification which states that students should be able to calculate cardiac output. The lesson begins by challenging the students to recall that the left ventricle is the heart chamber with the thickest myocardial wall. This leads into the introduction of stroke volume as the volume of blood which is pumped out of the left ventricle each heart beat. A quick quiz game is used to introduce a normative value for the stroke volume and students are encouraged to discuss whether males or females would have higher values and to explain why. A second edition of this quiz reveals a normative value for resting heart rate and this results into the introduction of the equation to calculate cardiac output. A series of questions are used to challenge their ability to apply this equation and percentage change is involved as well. The final part of the lesson looks at the hypertrophy of cardiac muscle and students will look at how this increase in the size of cardiac muscle affects the three factors and will be challenged to explain why with reference to the cardiac cycle that was covered in an earlier topic.

This fully-resourced lesson looks at the roles of glycolysis in aerobic and anaerobic respiration and explains how the sequence of reactions results in glucose being converted to pyruvate. The engaging PowerPoint and accompanying differentiated resources have been designed to cover point 7.4 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification. The lesson begins with the introduction of the name of the stage and then explains how the phosphorylation of the hexoses and the production of the ATP, coenzymes and pyruvate are the stages that need to be known for this specification. Time is taken to go through each of these stages and key points such as the use of ATP in phosphorylation are explained so that students can understand how this affects the net yield. A quick quiz competition is used to introduce NAD and the students will learn that the reduction of this coenzyme, which is followed by the transport of the protons and electrons to the cristae for the electron transport chain is critical for the overall production of ATP. Understanding checks, in a range of forms, are included throughout the lesson so that students can assess their progress and any misconceptions are immediately addressed. This lesson has been written to tie in with the other uploaded lessons on the Link reaction, Krebs cycle, oxidative phosphorylation and the production of lactate.

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 fully-resourced lesson looks at the details of glycolysis as the first stage of aerobic and anaerobic respiration and explains how the sequence of reactions results in glucose being converted to pyruvate. The engaging PowerPoint and accompanying differentiated resources have been designed to cover the second part of point 5.2 of the AQA A-level Biology specification which states that students should know glycolysis as the phosphorylation of glucose and the production and subsequent oxidation of triose phosphate. The lesson begins with the introduction of the name of the stage and then explains how the phosphorylation of the hexoses and the production of the ATP, coenzymes and pyruvate are the stages that need to be known for this specification. Time is taken to go through each of these stages and key points such as the use of ATP in phosphorylation are explained so that students can understand how this affects the net yield. A quick quiz competition is used to introduce NAD and the students will learn that the reduction of this coenzyme, which is followed by the transport of the protons and electrons to the cristae for the electron transport chain is critical for the overall production of ATP. Understanding checks, in a range of forms, are included throughout the lesson so that students can assess their progress and any misconceptions are immediately addressed. This lesson has been written to tie in with the other uploaded lessons on anaerobic respiration and the different stages of aerobic respiration (the Link reaction, Krebs cycle and oxidative phosphorylation)

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 the fourth part of point 5.2 of the AQA A-level Biology specification which states that students should know about this conversion and the production of reduced NAD 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 lesson looks at the detailed structure of DNA and builds on the knowledge from topic 1 to explain how this nucleic acid differs in the nucleus, mitochondria and chloroplasts of eukaryotic cells and in prokaryotic cells. Both the engaging PowerPoint and accompanying resources have been designed to cover the first part of point 6.1 (b) of the CIE International A-level Biology specification. As well as focusing on the differences between the DNA found in these two types of cells which includes the length, shape and association with histones, the various tasks will ensure that students are confident to describe how this double-stranded polynucleotide is held together by hydrogen and phosphodiester bonds. These tasks include exam-style questions which challenge the application of knowledge as well as a few quiz competitions to maintain engagement.

This detailed lesson explains how the process of transcription results in the production of messenger RNA (mRNA). Both the detailed PowerPoint and accompanying resource have been designed to specifically cover the first part of point 6.2 (d) of the CIE International A-level Biology specification. The lesson begins by challenging the students to recall that most of the nuclear DNA in eukaryotes does not code for polypeptides. This allows the promoter region and terminator region to be introduced, along with the structural gene. Through the use of an engaging quiz competition, students will learn that the strand of DNA involved in transcription is known as the template strand and the other strand is the coding strand. Links to previous lessons on DNA and RNA structure are made throughout and students are continuously challenged on their prior knowledge as well as they current understanding of the lesson topic. Moving forwards, the actual process of transcription is covered in a 7 step bullet point description where the students are asked to complete each passage using the information previously provided. An exam-style question is used to check on their understanding before the final task of the lesson looks at the journey of mRNA to the ribosome for the next stage of translation. This lesson has been written to challenge all abilities whilst ensuring that the most important details are fully explained.

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