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

This lesson describes and explains the changes in membrane potential of neurones, focusing on resting potential, depolarisation and repolarisation. The detailed PowerPoint and accompanying resources have been planned to cover the content of point (6) of topic 15.1 of the CIE A-level Biology specification. Hyperpolarisation and the refractory period are not covered in this lesson, but during a lesson titled “The refractory period” which covers specification point (8). This topic is commonly assessed in the terminal exams so a lot of time has been taken to design this resource to include a wide range of activities that motivate the students whilst ensuring that the content is covered in the depth of detail that will allow them to have a deep understanding. Interspersed within the activities are understanding checks and prior knowledge checks to enable the students to not only assess their progress against the current topic but also to challenge themselves on the links to earlier topics such as methods of movements across cell membranes. There are also several quiz competitions which introduce key terms and values in a fun and memorable way and discussion points to encourage the students to consider why a particular process or mechanism occurs. Over the course of the lesson, the students will learn and discover how the movement of ions across the membrane causes the membrane potential to change. They will see how the resting potential is maintained through the use of the sodium/potassium pump and potassium ion leakage. There is a real focus on depolarisation to allow students to understand how generator potentials can combine and if the resulting depolarisation then exceeds the threshold potential, a full depolarisation will occur. At this point in the lesson students will discover how the all or nothing response explains that action potentials have the same magnitude and that instead a stronger stimulus is linked to an increase in the frequency of the transmission. The rest of the lesson challenges the students to apply their knowledge to understand repolarisation.

This lesson focuses on the use and explanation of key genetic terms which will support students in their understanding of the topic 16 (inherited change) of the CIE International A-level Biology specification. In this topic, students are expected to use genetic diagrams to solve problems and this is only possible with a clear understanding of the genetic terminology that will be used in related exam questions. As some of these terms were met at GCSE, this fully-resourced lesson has been designed to include a wide range of activities that build on this prior knowledge and provide clear explanations as to their meanings as well as numerous examples of their use in both questions and exemplary answers. The main task provides the students with an opportunity to apply their understanding by recognising a dominance hierarchy in a multiple alleles characteristic and then calculating a phenotypic ratio when given a completed genetic diagram. Other tasks include prior knowledge checks, discussion points to encourage students to consider the implementation of the genetic terms and quiz competitions to introduce new terms, maintain engagement and act as an understanding check. The 16 terms are genome, gene, chromosome, gene locus, homologous chromosomes, alleles, dominant, recessive, genotype, codominance, multiple alleles, autosomes, sex chromosomes, phenotype, homozygous and heterozygous

This lesson acts as an introduction to topic 7.1 of the AQA A-level Biology specification and focuses on 16 key genetic terms that will support students in forming a deep understanding of inheritance. As some of these terms were met at GCSE, this fully-resourced lesson has been designed to include a wide range of activities that build on this prior knowledge and provide clear explanations as to their meanings as well as numerous examples of their use in both questions and exemplary answers. The main task provides the students with an opportunity to apply their understanding by recognising a dominance hierarchy in a multiple alleles characteristic and then calculating a phenotypic ratio when given a completed genetic diagram. Other tasks include prior knowledge checks, discussion points to encourage students to consider the implementation of the genetic terms and quiz competitions to introduce new terms, maintain engagement and act as an understanding check. The 16 terms are genome, gene, chromosome, gene locus, homologous chromosomes, alleles, dominant, recessive, genotype, codominance, multiple alleles, autosomes, sex chromosomes, phenotype, homozygous and heterozygous

This fully-resourced lesson challenges the students to use fully labelled genetic diagrams to interpret the results of monohybrid and dihybrid crosses as detailed in topic 7.1 (Inheritance) of the AQA A-level Biology specification. Step-by-step guides are used to demonstrate how diagrams for the inheritance of one and two genes should be constructed and a focus is given to the areas where students commonly make mistakes, such as in writing out the gametes. The main task of each section of the lesson provides an opportunity for the students to apply their understanding by calculating phenotypic ratios. All of the questions have fully-explained mark schemes and students can assess their progress and address any misconceptions immediately. Key genetic terminology is used throughout the lesson and mirrors that used in actual exam questions.

This fully-resourced REVISION lesson has been designed to enable the students to challenge their knowledge of the content of topic 16 (Inherited change) of the CIE A-level Biology specification. The engaging PowerPoint and accompanying differentiated worksheets 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: Homologous pairs of chromosomes The meanings of haploid and diploid The behaviour of chromosomes in meiosis Crossing over and random assortment as causes of genetic variation The use of key genetic terminology The use of genetic diagrams to solve problems including autosomal and sex-linkage, dihybrid inheritance and gene interactions The use of the chi-squared test Gene mutations Genetic control of protein production in prokaryotes Gibberellins and how they cause the breakdown of DELLA proteins Due to the extensiveness of this resource, it is likely that it will take a number of lessons to go through all of the activities

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 examples of stabilising, directional and disruptive selection as the three main types of selection. The PowerPoint and accompanying resources have been designed to cover the 1st part of point 6.1.2 (e) of the OCR A-level Biology specification which states that students should be able to demonstrate and apply an understanding of the factors that affect the evolution of a species. The lesson begins by making a link to a topic from module 4 as the students are challenged to use the mark, release, recapture method to calculate numbers of rabbits with different coloured fur in a particular habitat. 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 lesson has been designed to tie in with another uploaded lesson on genetic drift which covers the second part of this specification point.

This lesson focuses on the degenerate nature of the genetic code and explains how a mutation may not result in a change to the sequence of amino acids. The PowerPoint has been designed to cover the first part of point 4.3 of the AQA A-level Biology specification and it makes links to the upcoming lesson on gene mutations. The lesson begins by introducing the terms near universal and non-overlapping in addition to degenerate. A quick quiz competition is used to generate the number 20 so that the students can learn that there are 20 proteinogenic amino acids in the genetic code. This leads into a challenge, where they have to use their prior knowledge of DNA to calculate the number of different DNA triplets (64) and the mismatch in number is then discussed and related back to the lesson topic. Moving forwards, base substitutions and base deletions are briefly introduced so that they can see how although one substitution can change the primary structure, another will change the codon but not the encoded amino acid. The lesson concludes with a brief look at the non-overlapping nature of the code so that the impact of a base deletion (or insertion) can be understood when covered in greater detail in topic 8. This lesson has been specifically designed to tie in with the other lessons from topic 4.3 on gene mutations, chromosome mutations and meiosis.

This fully-resourced lesson describes the process of skeletal muscle contraction in terms of the sliding filament theory. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 7.2 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and includes the role of actin, myosin, troponin, tropomyosin, calcium ions and ATP. The lesson begins with a study of the structure of the thick and thin filaments. Students will recognise that the protruding heads of the myosin molecule are mobile and this enables this protein to bind to the binding sites when they are exposed on actin. This leads into the introduction of troponin and tropomyosin and key details about the binding of calcium to this complex is explained. Moving forwards, students are encouraged to discuss possible reasons that can explain how the sarcomere narrows during contraction when the filaments remain the same length. This main part of the lesson goes through the main steps of the sliding filament model of muscle contraction and the critical roles of the calcium ions and ATP are discussed. The final task of the lesson challenges the students to apply their knowledge by describing the immediate effect on muscle contraction when one of the elements doesn’t function correctly. This lesson has been written to tie in with another uploaded lesson on the structure of a muscle fibre which is covered in specification point 7.10

This fully-resourced lesson looks at the external and internal structure of the mammalian heart and explains how the differences in the thickness of the chamber walls is related to function. The engaging and detailed PowerPoint and accompanying resources have been designed to cover points 8.2 (a) and (b) of the CIE International A-level Biology specification As this topic 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. As detailed in specification point (b), time is taken to ensure that students can explain why the atrial walls are thinner than the ventricle 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 topics 8.1 and 8.2 including those which have already been covered like circulatory systems as well as those which are upcoming such as the cardiac cycle. 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.

This detailed and fully-resourced lesson describes and explains the pressure changes in the heart and arteries and the role of the valves movements in the cardiac cycle. The PowerPoint and accompanying resources have been designed to cover point 3.1.2 (f) of the OCR A-level Biology A specification and also covers the use of the equation stroke volume x heart rate to calculate cardiac output 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 next part 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. Moving forwards, the students are introduced to the stroke volume and meet normative values for this and for resting heart rate. This will lead into the calculation for cardiac output and a series of questions are used to test their ability to apply this equation as well as to calculate the percentage change which is a commonly assessed mathematical skill. This lesson has been written to tie in with the other uploaded lessons on the topics detailed in module 3.1.2 (Transport in animals)

This detailed lesson explains how observable features at a microscopic level can be used to classify living organisms into one of the five kingdoms. The engaging PowerPoint and accompanying resources have been designed to cover point 4.2.2 © (i) of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply an understanding of the features of the animalia, plantae, fungi, protoctista and prokaryotae kingdoms. This lesson begins with a knowledge recall as students have to recognise that prior to 1990, kingdom was the highest taxa in the classification hierarchy. Moving forwards, they will recall the names of the five kingdoms and immediately be challenged to split them so that the prokaryotae kingdom is left on its own. An opportunity is taken at this point to check on their prior knowledge of the structure of a bacterial cell from module 2.1.1. These prior knowledge checks are found throughout the lesson (along with current understanding checks) as students are also tested on their knowledge of the structure and function of cellulose. This is found in the section of the lesson where the main constituent of the wall can be used to distinguish between plantae, fungi and prokaryotae. Quick quiz competitions, such as YOU DO THE MATH and SAY WHAT YOU SEE are used to introduce key values and words in a fun and memorable way. The final part of the lesson looks at the protoctista kingdom and students will come to understand how these organisms tend to share a lot of animal or plant-like features. Both of the accompanying resources have been differentiated to allow students of differing abilities to access the work and this lesson has been written to tie in with the previously uploaded lesson on taxonomic hierarchy and the binomial naming system (4.2.2 a & b).

This lesson describes the classification of species into the taxonomic hierarchy and cover point 18.2 (a) of the CIE A-level Biology specification. The engaging PowerPoint and accompanying resources have been designed to show students how the domain, kingdom, phylum, class, order, family, genus and species are used in modern-day classification. The lesson begins by with a knowledge recall as students have to use the provided information about a mule to explain why a horse and donkey are considered to be members of different species. Moving forwards, students will learn that species is the lowest taxon in the modern-day classification hierarchy. The first of a number of rounds of a competition is used to engage the students whilst they learn the names of the 7 other taxa and the horse and the donkey from the earlier example are used to complete the hierarchy. Students are told that a binomial naming system is used in Biology to provide a universal name for each species and the final task of the lesson challenges them to apply their knowledge by completing a hierarchy for a modern-day human, by spotting the correct name for an unfamiliar organism

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

This detailed lesson explains how the process of transcription results in the production of mRNA, either directly from DNA in prokaryotes or following splicing in eukaryotes. Both the detailed PowerPoint and accompanying resource have been designed to specifically cover the second part of point 4.2 of the AQA A-level Biology specification but also provides important information that students can use when being introduced to gene expression in topic 8. 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. They will learn that the RNA strand formed at the end of transcription in eukaryotes is a primary transcript called pre-mRNA and then the details of splicing are explained. An exam-style question is used to check on their understanding before the final task of the lesson looks at the journey of mRNA to the ribosome for the next stage of translation. This lesson has been written to challenge all abilities whilst ensuring that the most important details are fully explained.

This lesson focuses on the structure of RNA and specifically the similarities and differences between this nucleic acid and DNA. The engaging and detailed PowerPoint and accompanying resource have been designed to cover the second part of point 6.1 (b) of the CIE International A-level Biology specification which states that students should be able to describe the structure of this nucleic acid. Students were introduced to the detailed structure of a nucleotide and DNA in previous lessons, so this lesson is written to tie in with those and continuously challenge prior knowledge as well as the understanding of the current topic. The lesson begins with the introduction of RNA as a member of the family of nucleic acids and this enables students to recognise that this polynuclotide shares a number of structural features that were previously seen in DNA. A quiz round called “A FAMILY AFFAIR” is used to challenge their knowledge of DNA to recognise those features that are also found on RNA such as the chain of linked nucleotides, pentose sugars, nitrogenous bases and phosphodiester bonds. The next task pushes them to consider features that have not been mentioned and therefore are differences as they answer a structured exam-style question on how RNA differs from DNA. Students will learn that RNA is shorter than DNA and this leads into the final part of the lesson where mRNA and tRNA are introduced and again they are challenged to use the new information explain the difference in size. Brief details of transcription and then translation are provided so that students are prepared for the upcoming lessons on protein synthesis

This fully-resourced lesson looks at the structure of genes and explores their role as a base sequence on DNA that codes for the amino acid sequence of a polypeptide. Both the PowerPoint and accompanying resource have been designed to cover point 6.2 (a) of the CIE International A-level Biology specification which states that students should understand how a gene codes for a polypeptide. The lesson begins with a prior knowledge check as the students have to recognise the key term chromosome from a description involving DNA and histones. This allows genes, as sections of a chromosome, to be introduced and the first of a number of quiz rounds is then used to get the students to meet the term locus so that they can understand how each gene has a specific location on a chromosome. Whenever possible, opportunities are taken to make links to the other parts of the CIE specification and this is utilised here as students are reminded that alternative versions of a gene (alleles) can be found at the locus. Moving forwards, students will learn that 3 DNA bases is a triplet and that each triplet codes for a specific amino acid. At this point, the genetic code is introduced and students are challenged to explain how the code contains 64 different triplets. By comparing this number against the number of different amino acids in proteins, students will see how each amino acid is encoded for by more than one triplet and how this explains the degenerate nature of the genetic code which forms a link to an upcoming lesson on gene mutations.