This lesson explains the principles of the polymerase chain reaction (PCR) and the PowerPoint has been designed to cover point 6.1.3 (d) of the OCR A-level Biology A specification A quick quiz competition is used to introduce the PCR abbreviation before students are encouraged to discuss the possible 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 focuses on each temperature and specifically the reasons behind the choice. Time is taken to examine the key points in detail, such as why Taq polymerase has to be used as it is not denatured at the high temperature as well as the involvement of the primers. This process is closely linked to other techniques like electrophoresis which is covered in a later lesson and ties are continuously made throughout the lesson This process is mentioned in other uploaded lessons in this module such as electrophoresis and genetic engineering to allow students to understand how it is critical for DNA analysis

This engaging lesson looks at the role of haemoglobin in transporting oxygen and carbon dioxide and compares the dissociation curves for foetal and adult haemoglobin. The detailed PowerPoint has been designed to cover points 3.1.2 (i & j) of the OCR A-level Biology A specification and includes references to the role of carbonic anhydrase and the formation of haemoglobinic acid and carbaminohaemoglobin. The lesson begins with a version of the quiz show Pointless to introduce haemotology as the study of the blood conditions. Students are told that haemoglobin has a quaternary structure and are challenged to use their prior knowledge of biological molecules to determine what this means for the protein. They will learn that each of the 4 polypeptide chains contains a haem group with an iron ion attached and that it is this group which has a high affinity for oxygen. Time is taken to discuss how this protein must be able to load (and unload) oxygen as well as transport the molecules to the respiring tissues. Students will plot the oxyhaemoglobin dissociation curve and the S-shaped curve is used to encourage discussions about the ease with which haemoglobin loads each molecule. At this point, foetal haemoglobin and its differing affinity of oxygen is introduced and students are challenged to predict whether this affinity will be higher or lower than adult haemoglobin and to represent this on their dissociation curve. The remainder of the lesson looks at the different ways that carbon dioxide is transported around the body that involve haemoglobin. Time is taken to look at the dissociation of carbonic acid into hydrogen ions so that students can understand how this will affect the affinity of haemoglobin for oxygen in an upcoming lesson on the Bohr effect. It is estimated that it will take in excess of 2 hours of A-level teaching time to cover the detail of these two specification points as covered in this lesson

This lesson focuses on the structure of RNA and specifically the similarities and differences between this nucleic acid and DNA so that students are prepared for the upcoming lessons on transcription and translation. The engaging and detailed PowerPoint and accompanying resource have been designed to cover part 1 of point 2.1.3 (g) of the OCR A-level Biology A specification which states that students should be able to describe the structure of molecules of messenger RNA, transfer RNA and ribosomal RNA. Students were introduced to nucleotides and the detailed structure of DNA in previous lessons, so this lesson is written to tie in with those and continuously challenge prior knowledge as well as understanding of the current topic. The lesson begins by reminding students that RNA is a member of the family of nucleic acids and therefore has a number of structural features that are commonly shared with DNA. A quiz round called “A FAMILY AFFAIR” is used to challenge their knowledge of DNA to recognise those features that are also found on RNA such as the chain of linked nucleotides, pentose sugars, nitrogenous bases and phosphodiester bonds. The next task pushes them to consider features that have not been mentioned and therefore are differences as they answer a structured exam-style question on how RNA differs from DNA. Students will learn that RNA is shorter than DNA and this leads into the final part of the lesson where mRNA and tRNA are introduced and again they are challenged to use the new information explain the difference in size. Brief details of transcription and then translation are provided so that students are prepared for the upcoming lessons on protein synthesis.

This revision resource has been designed to include a range of activities such as exam questions, understanding checks and quiz competitions which will motivate the students whilst they assess their understanding of the content found in module 2.1.4 (Enzymes) of the OCR A-level Biology A specification. The resource includes a detailed and engaging Powerpoint (70 slides) and associated worksheets The range of activities have been designed to cover as much of the content as possible but the following sub-topics have been given particular attention: The role of enzymes as biological catalysts that lower the activation energy The lock and key theory and the induced fit hypotheses The mechanism of enzyme action to include the tertiary structure The effect of inhibitors on the rate of enzyme-controlled reactions The effect of pH on the rate of reaction Coenzymes and cofactors The idea of an optimum temperature and explaining the decrease in rate when temperatures increase or decrease Calculating the temperature coefficient In addition to these topics, some topics from other modules such as the PCR and precursor molecules are tested in order to challenge the students on their ability to make links between the modules.

This is a fully-resourced lesson which covers the detail of point 5.1.3 (b) of the OCR A-level Biology A specification which states that students should be able to apply their understanding of the structures and functions of sensory, relay and motor neurones as well as the differences between myelinated and unmyelinated neurones. The PowerPoint has been designed to contain a wide range of activities that are interspersed between understanding and prior knowledge checks that allow the students to assess their progress on the current topics as well as challenge their ability to make links to topics from earlier in the modules. Quiz competitions like SAY WHAT YOU SEE are used to introduce key terms in a fun and memorable way. The students will be able to compare these neurones based on their function but also distinguish between them based on their structural features. Time is taken to look at the importance of the myelin sheath for the sensory and motor neurones. Students will be introduced to the need for the entry of ions to cause depolarisation and will learn that this is only possible at the nodes of Ranvier when there is a myelin sheath. Key terminology such as saltatory conduction is introduced and explained. The final task involves a comparison between the three neurones to check that the students have understood the structures and functions of the neurones. Throughout the lesson, links are made to the upcoming topic of the organisation of the nervous system (5.1.5) and students will be given additional knowledge such as the differences between somatic and autonomic motor neurones. This lesson has been designed for students studying on the OCR A-level Biology A course.

This engaging lesson covers the detail of the 2nd part of specification point 5.1.3 (d) of the OCR A-level Biology specification which states that students should demonstrate and apply an understanding of the importance of synapses in summation and control, including inhibitory and excitatory synapses. This is a topic which is generally poorly understood by students or brushed over so considerable time has been taken to design the activities to motivate the students so that the content is memorable whilst still being covered in detail. Links are continually made to earlier topics in this module such as synapses and generator potentials but also to topics covered in the previous year and still to be covered. The lesson begins by challenging the students to recognise a description of generator potential and they will then discover that this is also known as an EPSP. Students will recall that a small depolarisation may not lead to the opening of the voltage gated channels and therefore the full depolarisation which is needed for the initiation of an action potential and will discuss how this problem could be overcome. Lots of discussion points like this are included in the lesson to encourage the students to challenge and debate why a particular process of mechanism occurs. Students will therefore learn that EPSPs can be combined and this is known as summation. A quiz round is used to introduce temporal and spatial summation. Moving forwards, students are presented with a number of examples where they have to decide why type of summation is involved. Again, the lesson has been written to include real-life examples such as chronic pain conditions so the chances of the content sticking is increased. The final part of the lesson introduces IPSPs and the effect of these on summation and action potentials is discussed. This lesson has been designed for students studying on the OCR A-level Biology course and ties in well with the other uploaded lessons from module 5.1.3 on sensory receptors, neurones, nerve impulses and cholinergic synapses

This is a detailed lesson resource that covers the content of point 5.1.3 (a) of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply their understanding of the roles of mammalian sensory receptors. There is a particular focus on the Pacinian corpuscle to demonstrate how these receptors act as transducers by converting one form of energy into electrical energy which is then conducted as an electrical impulse along the sensory neurone. The lesson begins by looking at the different types of stimuli that can be detected. This leads into a written task where students have to form sentences to detail how thermoreceptors, rods and cones, hair cells in the inner ear and vibration receptors in the cochlea convert different forms of energy into electrical energy. Students will be introduced to the term transducer and will be challenged to work out what these cells carry out by using their sentences. As stated above, students will meet a Pacinian corpuscle and learn that this receptors detects pressure changes in the skin using the concentric rings of connective tissue in its structure. The rest of the lesson focuses on how ions are involved in the maintenance of resting potential and then depolarisation. Time is taken to look into the key details of these two processes so students are confident with this topic when met again during a lesson on the generation of action potentials. All of the tasks are differentiated to allow students of different abilities to access the work. As well as understanding checks to allow the students to assess their progress against the current topic, there are also a number of prior knowledge checks on topics like inorganic ions and methods of movement. This lesson has been designed for students studying the OCR A-level Biology course

This fully-resourced lesson describes the relationship between the structure, properties and functions of triglycerides in living organisms. The engaging PowerPoint and accompanying worksheets have been designed to be the first lesson in a series of two that cover specification points 2.1.2 (h), (i) & (j) of the OCR A-level Biology A course and the lesson contains numerous references to relevant future topics such as the importance of the myelin sheath for the conduction of an electrical impulse. The lesson begins with a focus on the basic structure and roles of lipids, including the elements that are found in this biological molecule and some of the places in living organisms where they are found. Moving forwards, the students are challenged to recall the structure of the carbohydrates from earlier in the sub-module so that the structure of a triglyceride can be introduced. Students will learn that this macromolecule is formed from one glycerol molecule and three fatty acids and have to use their understanding of condensation reactions to draw the final structure. Time is taken to look at the difference in structure and properties of saturated and unsaturated fatty acids and students will be able to identify one from the other when presented with a molecular formula. The final part of the lesson explores how the various properties of a triglyceride mean that it has numerous roles in organisms including that of an energy store and source and as an insulator of heat and electricity.

This lesson describes how random and non-random sampling strategies can be carried out to measure the biodiversity of a habitat. The PowerPoint and accompanying worksheets are part of the first lesson in a series of 2 which have been designed to cover the content of point 4.2.1 (b) (i) of the OCR A-level Biology A specification and this lesson specifically focuses on sampling plant species. The second lesson covers the sampling of animal species using apparatus such as pooters and sweeping nets. The lesson begins with a challenge, where the students have to recognise the terms random and stratified from descriptions that were met in modules 2.1.6 and 3.1.1. This introduces the concept of sampling and emphasises its importance in the measurement of biodiversity and the students will learn that there is random sampling as well as non-random sampling, and that one of these strategies is known as stratified. The next part of the lesson focuses on the random sampling of a habitat where the results found with a quadrat are used to estimate the population of sessile species like plants. Due to the heavy mathematical content in the A-level Biology exams, a step by step guide is used to walk the students through the key stages in these calculations and includes the extra steps needed when the quadrat does not have an area of 1 metre squared. A series of exam-style questions will then challenge them to apply their understanding and mark schemes are embedded in the PowerPoint to allow them to immediately assess their progress. The use of quadrats that have been divided into 100 squares and point frames to estimate percentage ground cover are also discussed and the overall advantages and disadvantages of random sampling are considered. Moving forwards, the stratified, opportunistic and systematic strategies of non-random sampling are discussed and again the advantages and disadvantages of all three are considered. Time is taken to focus on line and belt transects and students will learn that the latter can be particularly useful when an abiotic factor appears to change across a habitat.

This lesson discusses how biodiversity may be considered at different levels and describes how to calculate Simpson’s Index of diversity. The PowerPoint and accompanying worksheets have primarily been designed to cover points 4.2.1 (a, c and d) of the OCR A-level Biology A specification but also make links to the upcoming topics of classification, natural selection and adaptations A quiz competition called BIOLOGICAL TERMINOLOGY SNAP runs over the course of the lesson and this will engage the students whilst challenging them to recognise species, population, biodiversity, community and natural selection from their respective definitions. Once biodiversity as the variety of living organisms in a habitat is revealed, the students will learn that this can relate to a range of habitats, from those in the local area to the Earth. Moving forwards, the students will begin to understand that biodiversity can be considered at a range of levels which include within a habitat, within a species and within different habitats so that they can be compared. Species richness as a measure of the number of different species in a community is met and a biological example in the rainforests of Madagascar is used to increase its relevance. However, students will also be introduced to species evenness and will learn that in order for a habitat to be deemed to be biodiverse, it must be both species rich and even. The students are introduced to an unfamiliar formula that calculates the heterozygosity index and are challenged to apply their knowledge to this situation, as well as linking a low H value to natural selection. The rest of the lesson focuses on the calculation of Simpson’s Index of diversity and a 4-step guide is used to walk students through each part of the calculation. This is done in combination with a worked example to allow students to visualise how the formula should be applied to actual figures. Using the method, they will then calculate a value of D for a comparable habitat to allow the two values to be considered and the significance of a higher value is explained. All of the exam-style questions have mark schemes embedded in the PowerPoint to allow students to continuously assess their progress and understanding.

This lesson describes how the structure, actions and function of the loop of Henle in the kidney is pivotal in the production of urine. The PowerPoint and accompanying resource are part of a series of 4 lessons which have been designed to cover point 5.1.2 [c] of the OCR A-level biology A specification, which is titled "the structure, mechanisms of action and functions of the mammalian kidney. The lesson begins by challenging the students to recognise that the glomerular filtrate entering the loop will only contain water, ions and urea if the kidneys are functioning properly. Time is then taken to look at the structure of the loop of Henle, focusing on the descending and ascending limbs, and their differing permeabilities. Students will be reminded that this part of the nephron is located in the renal medulla, before a step-by-step guide is used to describe how the transfer of ions from the ascending limb to the descending limb, creates a very negative water potential in this region of the kidney. This allows water to move out of the descending limb to the tissue fluid and then into the capillaries. The next part of the lesson challenges students to consider the bigger picture as they learn that this decreasing water potential in the medulla allows water to be reabsorbed from the filtrate in the collecting duct too. The remainder of the lesson uses the real-world examples of the hopping mouse and kangaroo rat to check student understanding, and there are also prior knowledge checks to encourage students to make links to relevant content from earlier topics. All answers are embedded into the PowerPoint.

This lesson describes succession as the gradual, progressive changes in a ecosystem, moving from colonisation by the pioneer species to a climax community. The detailed PowerPoint and accompanying resources have been designed to cover point 6.3.1 (d) of the OCR A-level Biology specification, and therefore the lesson also describes deflected succession and the formation of a plagioclimax community. As shown in the cover image, the lesson uses a step by step guide to describe primary succession, introducing the different species at each stage, and explaining the vital roles they each perform. Time is taken to explain how the initial colonisation by algae and lichens as pioneer species is critical to form soil, which wasn’t previously present on the bare ground. The real-world example of Surtsey is used to increase relevance and students will hear about the changes that have occurred on this island over the last 67 years. Understanding checks are included at regular points to allow the students to assess their progress, and prior knowledge checks challenge them to recall content from earlier modules. Answers to all of the checks are embedded in the PowerPoint. The final part of the lesson considers how many ecosystems are prevented from reaching their climax community and this is known as deflected succession. Human influences are explored and again, real examples are used.

This lesson describes the nervous pathways of a range of reflex actions, including spinal reflex arcs and a cranial reflex, and their survival value is explored. The PowerPoint and accompanying resources have been planned to cover the content of point 5.1.5 (i) of the OCR A-level biology A specification. The lesson begins with a challenge, where the students have to spot the connections between 3 groups of 3 terms, and this will introduce different neurones, muscle tissues and reflexes for reference throughout. There are prior knowledge checks throughout the lesson, and one is immediately used to check on the students’ knowledge of the functions of the different structures in a nervous pathway and the order they are involved. The spinal reflex after an individual presses on a sharp pin is used to check that they can apply their knowledge to a real biological example. At this point, the potential for a reflex to be overridden if an unmyelinated relay neurone is involved is introduced and this is explained in detail later in the lesson. The knee jerk reflex is then discussed and students will understand that this is the choice for a reflex test because of the direct communication between the sensory and motor neurone. The final part of the lesson describes the corneal reflex as a cranial reflex and students will learn how it can be inhibited through conscious control by the higher part of the brain, as happens when an individual puts contact lenses on.

This clear and concise lesson explains how the inheritance of two or more genes that have loci on the same autosome demonstrates autosomal linkage. The engaging PowerPoint and associated resource have been designed to cover the part of point 6.1.2 (b[ii]) of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply their knowledge and understanding of the use of phenotypic ratios to identify autosomal linkage. This is a topic which can cause confusion for students so time was taken in the design to split the concept into small chunks. There is a clear focus on how the number of original phenotypes and recombinants can be used to determine linkage and suggest how the loci of the two genes compare. Important links to other topics such as crossing over in meiosis are made to enable students to understand how the random formation of the chiasma determines whether new phenotypes will be seen in the offspring or not. Linkage is an important cause of variation and the difference between observed and expected results and this is emphasised on a number of occasions. The main task of the lesson acts as an understanding check where students are challenged to analyse a set of results involving the inheritance of the ABO blood group gene and the nail-patella syndrome gene to determine whether they have loci on the same chromosome and if so, how close their loci would appear to be. This lesson has been written to tie in with the other lessons from module 6.1.2 (Patterns of Inheritance)

This is a detailed, engaging and fully-resourced REVISION LESSON which allows students of all abilities to assess their understanding of the content in module 2.1.3 (Nucleotides and nucleic acids) of the OCR A-level Biology A specification. Considerable time has been taken to design the lesson to include a wide range of activities to motivate the students whilst they evaluate their knowledge of DNA, RNA and the roles of these nucleic acids in DNA replication and protein synthesis. Most of the tasks have been differentiated so that students of differing abilities can access the work and move forward as a result of the tasks at hand. This lesson has been planned to cover as much of the specification as possible but the following sub-topics have received particular attention: The structure of DNA Phosphorylated nucleotides DNA replication Transcription and translation Gene mutations and their affect on the primary structure of a polypeptide The structure of RNA In addition to a focus on the current topic, links are made throughout the lesson to other topics such as the journey of an extracellular protein following translation and the cell cycle. If you like the quality of this revision lesson, please look at the other uploaded revision lessons for this module and for this specification

A detailed and engaging lesson presentation (74 slides) which consists of a series of exam questions, quick tasks and competitions to enable the students to assess their understanding of the topics found within Module 2. All of the exam questions have displayed mark schemes with explanations so that students can recognise errors and misconceptions and address them. Students will thoroughly enjoy the numerous competitions which include "Name the 007 bonds" and "Biology catchphrase".