This detailed and engaging lesson covers the detail of specification points 5.1.4 (c and d) of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply an understanding of the histology of the pancreas and the control of insulin secretion. There is a particular emphasis on structure throughout the lesson so that students can recognise the exocrine and endocrine tissues of the pancreas as well as describe their specific functions. The lesson begins with a list of endocrine glands and the students are challenged to select the gland which also has exocrine functions. This leads into a focus on the exocrine tissues of the pancreas, beginning with the enzymes that are secreted and form pancreatic juice. Students will discover how groups of these cells are called acini and the secretion of the enzymes into the lobule at the centre will lead to the intralobular ducts and finally the formation of the pancreatic duct. Moving forwards, students are introduced to the Islets of Langerhans and the specialised alpha and beta cells that are found within this endocrine tissue. The rest of this lesson looks at how the release of insulin from the beta cells is controlled. Some of the structures and substances involved have been met in earlier topics so a fun quiz round is used to see which students can recall these parts first. A series of questions and discussion points challenge the students to verbalise answers and to discuss key points so that the cascade of events that take place in the lead up to the release can be considered. In the final task, students have to describe these events in detail and this task has been differentiated so that students of differing abilities can access the work. This lesson has been specifically designed for students on the OCR A-level Biology A course and ties in well with the other lessons from module 5.1.4 on the control of blood glucose concentration and diabetes mellitus type I and II

This engaging and fully-resourced lesson looks at how genetic drift can arise after a genetic bottleneck or as a result of the Founder effect. The detailed PowerPoint and accompanying resources have been designed to cover the second part of point 6.1.2 (e) of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply an understanding of the factors that affect the evolution of a species. A wide range of examples are used to show the students how a population that descends from a small number of parents will have a reduction in genetic variation and a change in the frequency of existing alleles. Students are encouraged to discuss new information to consider key points and understanding checks in a range of forms are used to enable them to check their progress and address any misconceptions. Students are provided with three articles on Huntington’s disease in South Africa, the Caribbean lizards and the plains bison to understand how either a sharp reduction in numbers of a new population beginning from a handful of individuals results in a small gene pool. Links to related topics are made throughout the lesson to ensure that a deep understanding is gained. This lesson has been designed to tie in with another uploaded lesson on types of selection which is part of this specification point

This engaging and fully-resourced lesson looks at the effects of stabilising, directional and disruptive selection as the three main types of selection. The PowerPoint and accompanying resources have been designed to cover the 3rd part of point 7.3 of the AQA A-level Biology specification which states that students should be able to identify each type of selection by its effect on different phenotypes. The lesson begins with an introduction to the mark, release, recapture method to calculate numbers of rabbits with different coloured fur in a particular habitat. This method is covered later in topic 7 so this section of the lesson is designed purely to generate changes in numbers of the organisms. Sketch graphs are then constructed to show the changes in the population size in this example. A quick quiz competition is used to engage the students whilst introducing the names of the three main types of selection before a class discussion point encourages the students to recognise which specific type of selection is represented by the rabbits. Key terminology including intermediate and extreme phenotypes and selection pressure are used to emphasise their importance during explanations. A change in the environment of the habitat and a change in the numbers of the rabbits introduces directional selection before students will be given time to discuss and to predict the shape of the sketch graph for disruptive selection. Students are challenged to apply their knowledge in the final task of the lesson by choosing the correct type of selection when presented with details of a population and answer related questions.

This fully-resourced lesson explores how new species arise when changes in the gene pool of two populations prevents members from interbreeding and producing fertile offspring. The engaging PowerPoint and accompanying resources have been designed to cover the fifth part of point 7.3 of the AQA A-level Biology specification which states that students should be able to describe allopatric and sympatric speciation. The lesson begins by using the example of a hinny, which is the hybrid offspring of a horse and a donkey, to challenge students to recall the biological classification of a species. Moving forwards, students are introduced to the idea of speciation and the key components of this process, such as isolation and selection pressures, are covered and discussed in detail. Understanding and prior knowledge checks are included throughout the lesson to allow the students to not only assess their progress against the current topic but also to make links to earlier topics in the specification. Time is taken to look at the details of allopatric speciation and how the different mutations that arise in the isolated populations and genetic drift will lead to genetic changes. The example of allopatric speciation in wrasse fish because of the isthmus of Panama is used to allow the students to visualise this process. The final part of the lesson considers sympatric speciation and again a wide variety of tasks are used to enable a deep understanding to be developed.

This clear and concise lesson looks at the phenomenon known as the Bohr effect and describes and explains how an increased carbon dioxide concentration effects the dissociation of oxyhaemoglobin. The PowerPoint has been designed to cover the second part of point 3.4.1 of the AQA A-level Biology specification and continually ties in with the previous lesson on the role of haemoglobin. 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 looks at the cardiac cycle and relates the structure and operation of the mammalian heart to its function. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 1.4 (i) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification As the structure of the heart was covered at GCSE, the lesson has been planned to build on this prior knowledge whilst adding the key details which will enable students to provide A-level standard answers. The primary focus is the identification of the different structures of the heart but it also challenges their ability to recognise the important relationship to function. For example, time is taken to ensure that students can explain why the atrial walls are thinner than the ventricular walls and why the right ventricle has a thinner wall than the left ventricle. Opportunities are taken throughout the lesson to link this topic to the others found in topic 1 including those which have already been covered like circulatory systems as well as those which are upcoming such as the initiation of heart action. There is also an application question where students have to explain why a hole in the ventricular septum would need to be repaired if it doesn’t naturally close over time. The next part 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 cardiac diastole. Students are challenged 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. It is estimated that it will take in excess of 2 hours of allocated A-level teaching time to cover the detail included in this lesson as required by this specification point

This is a fully-resourced lesson which uses exam-style questions, quiz rounds, quick tasks and discussion points to challenge students on their understanding of the content of topics B4 - B6, that will assessed on PAPER 2. It has been specifically designed for students on the OCR Gateway A GCSE Combined Science course who will be taking the FOUNDATION TIER examinations but is also suitable for students taking the higher tier who need to ensure that the fundamentals are known and understood. The lesson has been written to take place at the hospital and the students will visit the various wards and health clinics day to check on their knowledge of the following sub-topics : Cancer The production of gametes by meiosis The meaning of diploid and haploid Sex determination The difference between communicable and non-communicable diseases Diseases caused by bacteria, viruses, fungi and protists Treatment of bacterial infections using antibiotics Evolution by natural selection in bacteria Vaccinations Genetic terminology Inheritance of disorders caused by dominant and recessive alleles Risk factors of non-communicable diseases Ecosystems The carbon cycle and the increase in carbon dioxide levels In order to maintain challenge whilst ensuring that all abilities can access the questions, the majority of the tasks have been differentiated and students can ask for extra support when they are unable to begin a question. Step-by-step guides have also been written into the lesson to walk students through some of the more difficult concepts such as genetic diagrams and interpreting the results and evolution by natural selection. Due to the extensiveness of this revision lesson, it is estimated that it will take in excess of 3 teaching hours to complete the tasks and therefore this can be used at different points throughout the duration of the course as well as acting as a final revision before the PAPER 2 exam.

This lesson describes the light-dependent stage of photosynthesis and focuses on the mechanisms involved in the production of ATP and reduced NADP. The detailed PowerPoint and accompanying resources have been designed to cover the details of point 5.2.1 (d) of the OCR A-level Biology A specification and has been specifically planned to link with the previous lesson on the structure of the chloroplast and photosynthesis and to prepare the students for the next lesson on the light-independent stage. The light-dependent stage is a process which students can find difficult to understand in the necessary detail so this lesson has been planned to walk them through all of the key details. Time is taken to describe the roles of the major protein complexes that are embedded in the thylakoid membrane and this includes the two photosystems, the cytochrome proton pump and ATP synthase. A series of exam-style questions have been written that link to other biological topics in this course such as eukaryotic cell structures and membrane transport as well as application questions to challenge them to apply their understanding. Some of these resources have been differentiated to allow students of differing abilities to access the work and to be pushed at the same time. Students will learn that there are two pathways that the electron can take from PSI and at the completion of the two tasks which describe each of these pathways, they will understand how ATP is generated in non-cyclic and cyclic photophosphorylation. The final task of the lesson asks them to compare these two forms of photophosphorylation to check that they understand when photolysis is involved and reduced NADP is formed. Due to the detail included in this lesson, it is estimated that it will take in excess of 2.5 hours of allocated A-level teaching time to complete.

This lesson describes the mechanism of breathing, including the roles of the ribcage, intercostal muscles and the diaphragm. The content of the engaging PowerPoint has been designed to cover the details of the fifth part of specification point 3.2 of the AQA A-level Biology specification and introduces the antagonistic interaction of the external and internal intercostal muscles. The lesson begins with a focus on the diaphragm and students will discover that this sheet of muscle is found on the floor of the thoracic cavity. Whilst planning the lesson, it was deemed important to introduce this region of the body at an early stage because the best descriptions will regularly reference the changes seen in this cavity. As the mechanism of inhalation is a cascade of events, the details of this process are covered in a step by step format using bullet points. At each step, time is taken to discuss the key details which includes an introduction to Boyle’s law that reveals the inverse relationship between volume and pressure. It is crucial that students are able to describe how the actions of the diaphragm, external intercostal muscles and ribcage result in an increased volume of the thoracic cavity and a subsequent decrease in the pressure, which is below the pressure outside of the body. At this point, their recall of the structures of the mammalian gas exchange system is tested, to ensure that they can describe the pathway the air takes on moving into the lungs. The remainder of the lesson involves a task which challenges the students to describe exhalation and then the accessory muscles involved in forced ventilation are also considered.

This detailed lesson describes the pressure changes that occur during the cardiac cycle and explains how ECG traces can be interpreted. The PowerPoint and accompanying resources have been designed to cover points 4.4 (iii) & (v) of the Edexcel A-level Biology B specification and focuses on the importance of the valves in ensuring unidirectional movement of blood during the cycle. 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. The remainder of the lesson focuses on the ECG and explains how these traces can be interpreted to diagnose heart problems. A quiz competition is used to introduce the reference points of P, QRS and T on a normal sinus rhythm before time is taken to explain their representation with reference to the cardiac cycle. Moving forwards, a SPOT the DIFFERENCE task is used to challenge the students to recognise differences between sinus rhythm and some abnormal rhythms including tachycardia and atrial fibrillation. Bradycardia is used as a symptom of sinus node disfunction and the students are encouraged to discuss this symptom along with some others to try to diagnose this health problem.

This fully-resourced lesson describes how Mycobacterium tuberculosis and Human Immunodeficiency virus infect human cells. The PowerPoint and accompanying resources have been designed to cover point 6.6 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and ties in directly with the previous lesson where the structure of bacteria and viruses were compared. The lesson begins by ensuring that students recognise that TB is caused by the infection of a species of bacteria known as Mycobacterium tuberculosis and they will challenged to use their knowledge of scientific classification to recall that this pathogen is found in the mycobacteria genus. At this point, the students are told that the cell walls of this genus contain mycolic acids and later in the lesson they will have to work out that this specialist feature enables this pathogen to survive phagocytosis. A series of exam-style questions will challenge their knowledge of the respiratory and immune systems as they can understand how the bacterium travels to the alveoli where it is engulfed by a macrophage. Key terms like granuloma and necrosis are introduced and the sequence of events that occur following the formation of this aggregate of cells is described. The structure of viruses was covered during the previous lesson, so this next part of the lesson starts by challenging the students to recall the capsid, genetic material in the form of viral RNA and the lipid envelope. At this point, the students are introduced to gp120, the glycoprotein which is exposed on the surface of the lipid envelope, as this structure is critical for the entry of the virus into host cells. Students will annotate a basic diagram of HIV with these four structures which also has gp41 labelled. A quick quiz competition introduces the names of the enzymes found inside the capsid Moving forwards, the main task of this part of the lesson describes how HIV binds to the helper T cells, injects its capsid and integrates its DNA into the host’s genome in order to replicate to form virus particles (virions). Students are guided through the formation of a detailed answer about the mechanism of HIV and have to input key terms and structures where information is missing. Students will learn that the increase in the number of virus particles and a decrease in helper T cells and other immune cells results in infections like TB and by opportunistic pathogens and that this stage is recognised as AIDS

This lesson describes the principles of hormone production by endocrine glands and the two modes of action on target cells. The detailed PowerPoint and accompanying resources have been primarily designed to cover points 9.2 (i) & (ii) of the Edexcel A-level Biology B specification but can also be used as a revision tool to check on their knowledge of topics like biological molecules and transcription factors Students should have a base knowledge of the endocrine system from GCSE so this lesson has been planned to build on that knowledge and to add the detail needed at this level. The lesson begins by challenging this knowledge to check that they understand that endocrine glands secrete these hormones directly into the blood. Students will learn that most of the secreted hormones are peptide (or protein) hormones and a series of exam-style questions are used to challenge them on their recall of the structure of insulin as well as to apply their knowledge to questions about glucagon. Moving forwards, the students are reminded that hormones have target cells that have specific receptor sites on their membrane. The relationship between a peptide hormone as a first messenger and a second messenger on the inside of the cell is described to allow students to understand how the activation of cyclic AMP triggers a cascade of events on the inside of the cell. The rest of the lesson focuses on steroid hormones and specifically their ability to pass through the membrane of a cell and to bind to transcription factors, as exemplified by oestrogen.

This lesson describes how the chemical formula of an ionic compound can be deduced using the formulae of the constituent ions. The PowerPoint and accompanying worksheet have been designed to cover point 1.26 of the Edexcel GCSE Chemistry specification and also cover the same point in the Chemistry section of the Combined Science course. This lesson builds on the knowledge acquired in previous lessons when students learnt how to identify the charge of an ion based on the group of the atom. A step by step guide is used to show them how the transfer method can be used to write the formulae for compounds including halides and oxides. Time is taken to introduce the formulae for sulphate, carbonate, hydroxide and nitrate ions and the students are shown how brackets may be needed when writing formulae for compounds containing these ions. Understanding checks in the form of questions and quiz competitions are used to allow the students to assess their progress