This lesson describes how the eyepiece graticule and stage micrometer are used to measure the size of an object with an optical microscope. The PowerPoint and accompanying resource have been designed to cover the second part of point 2.1.3 of the AQA A-level Biology specification The main task of this concise lesson involves a step by step guide which walks students through the methodology and the use of the scale on the stage micrometer to identify the size of the divisions of the eyepiece graticule. This will need them to convert between units and as this was covered in the previous lesson, a number of prior knowledge checks will check that they are able to do this. Moving forwards, the students are challenged to apply this method to a series of exam-style questions and the mark scheme is displayed on the PowerPoint so that they can assess their understanding.

This detailed and engaging lesson looks at the culture of transformed host cells as an in vivo method to amplify DNA fragments. Both the PowerPoint and accompanying resources have been designed to cover the third part of point 8.4.1 of the AQA A-level Biology specification and ties in with the previous two lessons in this sub-topic on producing DNA fragments and the polymerase chain reaction. The lesson begins with the introduction of the terms transgenic and transformed. Students will learn that bacterial cells are the most commonly transformed cells so the next task challenges their recall of the structures of these cells so that plasmid DNA can be examined from that point onwards. A quick quiz competition is used to introduce the key term, vector, and then the rest of the lesson looks at the details of the five steps involved in the transformation of the host cell: Remove and prepare the plasmid to act as a vector Insert the DNA fragment into the vector Transfer the recombinant plasmid into the host cell Identify the cells which have taken up the recombinant plasmid All the transformed host cells to replicate and express the novel gene Time is taken to explore the finer details of each step such as the addition of the promoter and terminator regions, use of the same restriction enzyme to cut the plasmid as was used to cut the gene and the different types of marker genes. Links are continuously made to the previous lessons in this topic so that students feel confident to answer assessment questions which bring in knowledge from all of the sections.

This lesson looks at the homologous series of alcohols, focusing on the properties that they share and guiding students through naming and drawing displayed formula to represent them. It has been designed for GCSE students and time is taken to embed a few selected key details as dictated by the exam board specification. The lesson begins with students meeting the formula for ethanol. This substance will provide the backbone to their understanding as they are guided through drawing the displayed formula so they can visualise how it is done and use to draw diagrams for the others. Students are shown how the general formula for the alkanes and alkenes can be worked out and then challenged to use this to work out the general formula for the alcohols. There is a brief look at the reactions with oxygen and the products that can be made depending upon whether sufficient oxygen is available or not.

This fully-resourced lesson describes the ultrastructure of a prokaryotic cell and the function of the structures found in these cells. The engaging PowerPoint and accompanying resources have been designed to cover specification point 3.5 (i) & (ii) as detailed in the Edexcel International A-level Biology specification and also compares these cells against the eukaryotic cells that were met in the previous lesson. A clear understanding of terminology is important for A-level Biology so this lesson begins with a challenge, where the students have to recognise a prefix that they believe translates as before or in front of . This leads into the discovery of the meaning of prokaryote as before nucleus and this acts to remind students that these types of cell lack this cell structure. Links to the previous lessons on the eukaryotic cells are made throughout the lesson and at this particular point, the students are asked to work out why the DNA would be described as naked and to state where it will be found in the cell. Moving forwards, the students will discover that these cells also lack membrane bound organelles and a quick quiz competition challenges them to identify the specific structure that is absent from just a single word. In addition to the naked DNA, students will learn that there are also ribosomes in the cytoplasm and will discover that these are smaller than those found in the cytoplasm of an eukaryotic cell (but the same size as those in chloroplasts and mitochondria). The remainder of the lesson focuses on the composition of the cell wall, the additional features of prokaryotic cells such as plasmids and there is also the introduction of binary fission as the mechanism by which these organisms reproduce

This engaging lesson covers the final details of specification point 6.4.2 of the AQA A-level Biology specification which states that students should be able to describe the causes and control of diabetes mellitus type I and II. The lesson has been designed to take place in a diabetes clinic where students will be challenged to perform a number of roles such as diagnosing a patient with either type I or II and to write a letter to this patient explaining how the disease was caused and any treatments that will be recommended to control the disease. It has been planned to build on the knowledge that they will have of these diseases from GCSE and links are made to other A-level topics such as the beta cells of the pancreas which they considered during the lesson on the control of blood glucose concentration. This lesson has been designed for students taking the AQA A-level Biology course and runs alongside the uploaded lesson on the control of blood glucose concentration as well as the other lessons that have been added on topic 6

This concise lesson covers the content of specification point 5.1.5 (l) of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply an understanding of the action of neuromuscular junctions. Due to a number of similarities between these structures and cholinergic synapses, this lesson uses prior knowledge of these connections between neurones to build a good understanding of the junctions. Students will discover that the events that occur at an axon tip mirror those which happen at the pre-synaptic bulb and this is then developed to look at the differences in terms of the events once the acetylcholine has bound to its receptor sites. There is a focus on the structure of the sarcolemma and time is taken to explain how the action potential is passed from this membrane to the transverse tubules in order to stimulate the release of calcium ions from the sarcoplasmic reticulum. As a result, this lesson ties in nicely with the following lesson on the contraction of skeletal muscle and students will be able to link the binding to troponin in that lesson to the release of these ions from this lesson. Both of the main tasks of the lesson have been differentiated so that students of all abilities can access the work and make progress. This lesson has been designed for those students studying on the OCR A-level Biology course and ties in nicely with the other uploaded lessons on module 5.1.5 (Animal and plant responses)

This lesson describes the structure of the chromosome, including DNA, histone proteins, chromatids, centromeres and telomeres. The PowerPoint and accompanying worksheets have been primarily designed to cover point 5.1 (a) of the CIE A-level Biology specification but has been specifically planned to provides links to the upcoming topics of the cell cycle, mitosis, meiosis and DNA replication. The lesson begins with a prior knowledge check, where the students have to recall why the DNA in prokaryotic cells is described as being naked. This re-introduces histone proteins, and then time is taken to describe that the wrapping of DNA molecules around these proteins forms the linear chromosomes in the nucleus of eukaryotic cells. A series of 7 exam-style questions are used throughout the lesson and challenge the students to apply their knowledge and understanding to unfamiliar situations and challenge their knowledge of topics 1 and 2 (cell structure and biological molecules). The mark schemes for all of these questions are embedded into the PowerPoint to allow the students to assess their progress. Moving forwards, a quiz competition is used to introduce the terms diploid, chromatid and centromere and the S phase of interphase in a fun and memorable way. Students will learn that the duplication of chromosomes results in pairs of identical sister chromatids that are joined by a centromere. The importance of the splitting of the centromere in mitosis is explained and then the students are challenged to explain why the non-sister chromatids are involved in crossing over, when variation is needed. The final part of the lesson considers the repetitive nucleotide sequences found on the end of chromosomes that are known as telomeres and students will gain an initial understanding about their structure so they are prepared for the upcoming lesson on their significance

This detailed, concise lesson describes and explains how the electron transport chain and chemiosmosis are involved in the synthesis of ATP by oxidative phosphorylation. The PowerPoint has been designed to cover point 7.6 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and also looks at the role of the enzyme, ATP synthase. The lesson begins with a discussion about the starting point of the reaction. In the previous stages, the starting molecule was the final product of the last stage but in this stage, it is the reduced coenzymes which release their hydrogen atoms. Moving forwards, the process of oxidative phosphorylation is covered in 7 steps and at each point, key facts are discussed and explored in detail to enable a deep understanding to be developed. Students will see how the proton gradient is created and that the flow of protons down the channel associated with ATP synthase results in a conformational change and the addition of phosphate groups to ADP. Understanding checks are included throughout the lesson to enable the students to assess their progress. This lesson has been written to tie in with the other uploaded lessons on glycolysis, the Link reaction and Krebs cycle and anaerobic respiration.

A detailed and engaging lesson presentation (52 slides) and accompanying worksheet that looks at competition between organisms and the different types of relationships that exist as a result of this interaction. The lesson begins by looking at the meaning of the biological term, "competition", and then introduces this when it occurs between the same species and different species. Students are challenged to consider the different resources that animals compete for before an activity based competition is used to get them to recognise how this competition can cause changes to the population size. Moving forwards, students will meet the three main types of ecological relationship and look at them in greater detail, with predation being a main focus. There are regular progress checks throughout the lesson (with displayed answers) so that students can assess their understanding. This lesson has been designed for GCSE students but can be used with more-able KS3 students who are looking at ecosystems and the relationships that exist within them

This lesson describes how to calculate the cardiac output as the product of stroke volume and the heart rate. The PowerPoint and accompanying resource have been designed to cover point 7.13 (i) of the Edexcel International A-level Biology specification. The lesson begins by challenging the students to recognise that the left ventricle has the most muscular wall of all of the heart chambers. This allows the stroke volume to be introduced as the volume of blood ejected from the left ventricle each heart beat and then a quiz competition is used to introduce normative values for the stroke volume and the heart rate. Moving forwards, students will learn that the cardiac output is the product of the stroke volume and the heart rate. A series of exam-style questions will challenge the students to use this formula and to manipulate it and to work out the percentage change. The final part of the lesson looks at the adaptation of the heart to aerobic training in the form of cardiac hypertrophy and then the students are challenged to work out how this would affect the stroke volume, the cardiac output and the resting heart rate.

This lesson describes how an interaction of muscles, tendons, the skeleton and ligaments is needed for movement of the human body. The PowerPoint and accompanying resources have been designed to cover point 7.9 of the Edexcel International A-level Biology specification and also includes descriptions of antagonistic muscle pairs, extensors and flexors. At the start of the lesson, the prep room skeleton is used as the example to show that bones without muscles are bones that are unable to move (unaided). Moving forwards, the students will learn that skeletal muscles are attached to bones by bundles of collagen fibres known as tendons and as they covered the relationship between the structure and function of collagen in topic 2, a task is used that challenges their recall of these details. This will allow them to recognise that the ability of this fibrous protein to withstand tension is important for the transmission of the force from the muscle to pull on the moveable bone. A series of quick quiz competitions introduce the key terms of flexion and antagonistic and then an exam-style question challenges them to recognise the structures involved in extension at the elbow. The remainder of the lesson focuses on the role of ligaments and one final example of extension at the knee joint will demonstrate how the interaction of all of the structures met over the course of the lesson is needed for movement

This lesson describes how solutes are selectively reabsorbed in the proximal tubule. The PowerPoint and accompanying resource have been designed to cover the first part of specification point 7.20 of the Edexcel International A-level Biology specification and builds on the knowledge gained in the previous lessons on the microscopic 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 reminds students of the meaning of homeostasis and describes the how thermoregulation maintains the body in dynamic equilibrium during exercise. The PowerPoint has been designed to cover point 7.17 of the Edexcel International A-level Biology specification. Students were introduced to homeostasis at GCSE and this lesson has been written to build on that knowledge and to add the key detail needed at this level. Focusing on the three main parts of a homeostatic control system, the students will learn about the role of the internal and peripheral thermoreceptors, the thermoregulatory centre in the hypothalamus and the range of effectors which bring about the responses to restore optimum levels. The following responses are covered in this lesson: Vasodilation Increased sweating Body hairs In each case, time is taken to challenge students on their ability to make links to related topics such as the arterioles involved in the redistribution of blood and the high specific latent heat of vaporisation of water.

This fully-resourced lesson explains how the transcription of target genes can be stimulated or inhibited by transcription factors. Both the PowerPoint and the accompanying resources have been designed to cover the first part of point 8.2.2 of the AQA A-level Biology specification and links are continuously made throughout the lesson to the topic of protein synthesis which was covered in topic 4.2. The lesson begins with a recall of the meaning of the terms genome and proteome so that a discussion can begin on whether a cell wants to express every gene and produce all of the possible proteins all of the time. As the answer to this is no, the idea of transcription factors is introduced. In order to fully understand this topic, students need to recall that the role of the promoter region is to bind RNA polymerase to initiate transcription. Students will learn that the factors have a DNA-binding domain and that some also have ligand-binding domains which allow molecules like hormones to bind. Moving forwards, the students are introduced to a group of substances called DELLA proteins which inhibit plant development. The way that transcription begins once the inhibition by the proteins has been removed is similar to the action of oestrogen and students are able to use this information as a guide during the final task where they have to order the sequence of events that take place once this steroid hormone binds to its transcription factor.

An engaging lesson presentation (36 slides) that looks at the three types of muscle that are found in the body and then focusses on the structure and features of the involuntary muscles, cardiac and smooth. The lesson begins by challenging the students to recall the names of the different types and then gets them to recognise that cardiac and smooth are able to contract without conscious thought. Moving forwards, time is taken to look at the details of these muscles and key terminology such as intercalated discs and gap junctions are introduced so that students can understand how they perform their different functions. There are regular progress checks throughout the lesson so that students can assess their understanding. This lesson has been designed for A-level Biology lessons.

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 lesson describes how an increased carbon dioxide concentration affects the dissociation of oxyhaemoglobin, the Bohr effect. The PowerPoint and accompanying resources have been designed to cover the second part of point 4.5 (i) of the Edexcel A-level Biology B specification and continually ties in with the previous lesson on the role of haemoglobin and dissociation curves. 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 lesson describes the structure and function of synapses in nerve impulse transmission and focuses on acetylcholine as a neurotransmitter. The PowerPoint and accompanying resources have been designed to cover point 8.6 (i) of the Edexcel International A-level Biology specification, using a cholinergic synapse as the main example The lesson begins by using a version of the WALL from “Only Connect” which asks the students to group 12 words into three groups of 4. Not only will this challenge their prior knowledge from topics earlier in this topic but it will also lead to the discovery of four of the structures that are found in a synapse. Moving forwards, students are introduced to acetylcholine as the neurotransmitter involved at cholinergic synapses and they will start to add labels to the structures found in the pre-synaptic bulb. Time is taken to focus on certain structures such as the voltage gated channels as these types of channel were met previously when looking at the depolarisation of a neurone. There is plenty of challenge and discovery as students are pushed to explain why organelles like mitochondria would be found in large numbers in the bulb. With this process being a cascade of events, a bullet point format is used to ensure that the key content is taken in by the students and again key points like exocytosis and the action of acetylcholinesterase are discussed further. Understanding checks and prior knowledge checks are included throughout the lesson so that students can not only assess their progress against the current topic but also see whether they can make links to earlier topics.

This lesson describes the similarities and differences between the structure and function of haemoglobin and myoglobin. The PowerPoint and accompanying resource have been designed to cover point 4.5 (iii) of the Edexcel A-level Biology B specification Students have already covered the structure and function of haemoglobin in topics 1.3 and 4.5, so this concise lesson has been planned to challenge that knowledge. Students are introduced to myoglobin and will learn that this is an oxygen-binding protein found in the skeletal muscle tissue. Therefore the first part of the lesson focuses on slow twitch muscle fibres, where the content of myoglobin is high, and this presents an opportunity for links to be made to respiration, mitochondria and capillaries. The main part of the lesson challenges the students to compare the two proteins on structure and function including the number of polypeptide chains and affinity for oxygen and students can assess their understanding through use of the displayed mark schemes to the series of exam-style questions.

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.