This detailed 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 ultrafiltration. The aim of the design was to give the students the opportunity to discover this particular function and to be able to explain how the mechanisms found in the glomerulus and the Bowman’s capsule control the movement of small molecules out of the blood plasma. Key terminology is used throughout and students will learn how the combination of the capillary endothelium and the podocytes creates filtration slits that allow glucose, water, urea and ions through into the Bowman’s capsule but ensure that blood cells and plasma proteins remain in the bloodstream. A number of quiz competitions are used to introduce key terms and values in a fun and memorable way whilst understanding and prior knowledge checks allow the students to assess their understanding of the current topic and to challenge themselves to make links to earlier topics. The final task of the lesson challenges the students to apply their knowledge by recognising substances found in a urine sample that shouldn’t be present and to explain why this would cause a problem This lesson has been written for students studying on the OCR A-level Biology A course and ties in nicely with the other 5.1.2 kidney lessons on the structure of the nephron, selective reabsorption, osmoregulation and kidney failure

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 looks at how heart rate is controlled by the cardiovascular control centre in the medulla oblongata. The engaging and detailed PowerPoint and accompanying resources have been designed to cover the first part of point 7.9 (ii) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification but also ties in well with previously covered topics and provides a good introduction to control systems which are covered later in topic 7 and 8. 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 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 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 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 engaging and fully-resourced lesson looks at the myogenic nature of cardiac muscle and explores the roles of the SAN, AVN and Purkyne tissue in the initiation and control of heart action. The PowerPoint and accompanying resources have been designed to cover points 8.2 (d) of the CIE International A-level Biology 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 8.1. 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 detail

This fully-resourced lesson explores how pyruvate can be converted to lactate or ethanol using reduced NAD and that the reoxidation of the coenzyme allows glycolysis to continue. The engaging and detailed PowerPoint and accompanying differentiated resources have been designed to cover points 12.2 (j) and (k) of the CIE International A-level Biology specification which states that students should be able to explain the production of a small yield of ATP in anaerobic conditions and recognise the concept of an oxygen debt The lesson begins with a focus on the coenzyme, NAD, and students are challenged to recall details of its role in the oxidation of triose phosphate. Students will learn that oxidative phosphorylation in aerobic respiration allows these coenzymes to be reoxidised but that another metabolic pathway has to operate when there is no oxygen. Time is taken to go through the lactate and ethanol fermentation pathways and students are encouraged to discuss the conversions before applying their knowledge to complete diagrams and passages about the pathways. Understanding checks in a range of forms are used to enable the students to assess their progress whilst prior knowledge checks allow them to recognise the links to earlier topics. Students will also be introduced to the oxygen debt and will learn how the volume consumed after vigorous exercise is used to catabolise lactic acid and restore the body’s stores to normal levels. This lesson has been written to tie in with the other uploaded lessons on the stages of aerobic respiration.

This fully-resourced lesson looks at the double, closed circulatory system as found in a mammal and considers how the pulmonary circulation differs from the systemic circulation. The engaging PowerPoint and accompanying resources have been designed to cover point 8.1 (a) of the CIE International A-level Biology specification The lesson begins with a focus on the meaning of a double circulatory system and checks that students are clear in the understanding that the blood passes through the heart twice per cycle of the body. Beginning with the pulmonary circulation, students will recall that the pulmonary artery carries the blood from the right ventricle to the lungs. An opportunity is taken at this point to check on their knowledge of inhalation and the respiratory system as well as the gas exchange between the alveoli and the capillary bed. A quick quiz is used to introduce arterioles and students will learn that these blood vessels play a crucial role in the changes in blood pressure that prevent the capillaries from damage. When looking at the systemic circulation, time is taken to look at the coronary arteries and renal artery as students have to be aware of these vessels in addition to the ones associated with the heart. In the final part of the lesson, students are challenged to explain how the structure of the heart generates a higher pressure in the systemic circulation and then to explain why the differing pressures are necessary. As a result of the constant reference to the heart, the blood vessels and the blood, students will be reminded that these are the components of the circulatory system

This fully-resourced looks at the phenomenon known as the Bohr effect and describes and explains how an increased carbon dioxide concentration effects the dissociation of adult oxyhaemoglobin. The PowerPoint and accompanying resources have been designed to cover point 8.1 (g) of the CIE International A-level Biology specification and continually ties in with the previous lesson on the role of haemoglobin in carrying oxygen. The lesson begins with a terminology check to ensure that the students can use the terms affinity, oxyhaemoglobin and dissociation. In line with this, they are challenged to draw the oxyhaemoglobin dissociation curve and are reminded that this shows how oxygen associates with haemoglobin but how it dissociates at low partial pressures. Moving forwards, a quick quiz is used to introduce Christian Bohr and the students are given some initial details of his described effect. This leads into a series of discussions where the outcome is the understanding that an increased concentration of carbon dioxide decreases the affinity of haemoglobin for oxygen. The students will learn that this reduction in affinity is a result of a decrease in the pH of the cell cytoplasm which alters the tertiary structure of the haemoglobin. Opportunities are taken at this point to challenge students on their prior knowledge of protein structures as well as the bonds in the tertiary structure. The lesson finishes with a series of questions where the understanding and application skills are tested as students have to explain the benefit of the Bohr effect for an exercising individual.

This fully-resourced lesson explains how gene mutations can occur by substitution, deletion and insertion and explores how these base pair changes can affect the primary structure of the polypeptide and therefore the phenotype. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 16.2 (e) of the CIE International A-level Biology specification which states that students should understand how these mutations occur and can affect the phenotype. 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 topic 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 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 fully-resourced REVISION lesson has been written to challenge the students on their knowledge of the content of topic 1 (Cell structure) of the CIE International A-level Biology specification. The PowerPoint and accompanying resources will motivate the students whilst they assess their understanding of the content and identify any areas which may require further attention. The wide range of activities have been written to cover as much of the topic as possible but the following specification points have been given particular focus: ATP is produced in mitochondria and chloroplasts and the role of ATP in cells Recognising eukaryotic cell structures and outlining their functions Calculating actual sizes from electron micrographs The structural features of a typical prokaryotic cell The key features of viruses as non-cellular structures Distinguish between resolution and magnification Quiz rounds such as “GUESS WHO of CELL STRUCTURES” and “YOU DO THE MATH” are used to test the students on the finer details of their knowledge of the structure and functions of the organelles and some key numerical facts

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 looks at the use of the polymerase chain reaction (PCR) as an in vitro method to amplify DNA fragments as part of the recombinant DNA technology process. The clear PowerPoint has been designed to cover the second part of point 8.4.1 of the AQA A-level Biology specification. A quick quiz competition is used to introduce the PCR abbreviation before students are encouraged to discuss the identity of the enzyme involved and to recall the action of this enzyme. Students will learn that this reaction involves cyclical heating and cooling to a range of temperatures so the next part of this lesson looks at these particular temperatures so the important parts of each of the steps can be understood. Time is taken to examine the key points in detail, such as the specific DNA polymerase that is used and how it is not denatured at the high temperature as well as the involvement of the primers.