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

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 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 detailed lesson describes and explains the pressure and volume changes and associated valve movements that occur during the cardiac cycle to maintain the unidirectional flow of blood. The PowerPoint and accompanying resource have been designed to cover the 5th part of point 3.4.1 of the AQA A-level Biology specification. The start of the lesson introduces the cardiac cycle as well as the key term systole, so that students can immediately recognise that the three stages of the cycle are atrial and ventricular systole followed by diastole. Students are challenged on their prior knowledge of the structure of the heart as they have to name and state the function of an atrioventricular and semi-lunar valve from an internal diagram. This leads into the key point that pressure changes in the chambers and the major arteries results in the opening and closing of these sets of valves. Students are given a description of the pressure change that results in the opening of the AV valves and shown where this would be found on the graph detailing the pressure changes of the cardiac cycle. They then have to use this as a guide to write descriptions for the closing of the AV valve and the opening and closing of the semi-lunar valves and to locate these on the graph. By providing the students with this graph, the rest of the lesson can focus on explaining how these changes come about. Students have to use their current and prior knowledge of the chambers and blood vessels to write 4 descriptions that cover the cardiac cycle. The final part of the lesson covers the changes in the volume of the ventricle. This lesson has been written to tie in with the other uploaded lessons on the circulatory system as detailed in topic 3.4.1 (Mass transport in animals)

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 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 detailed lesson describes the structure and properties of the cell membrane, focusing on the phospholipid bilayer and membrane proteins. Fully resourced, the PowerPoint and accompanying worksheets have been designed to cover the first part of point 2.3 of the AQA A-level Biology specification and clear links are made to Singer and Nicholson’s fluid mosaic model The fluid mosaic model is introduced at the start of the lesson so that it can be referenced at appropriate points throughout the lesson. Students were introduced to phospholipids in topic 1 and so an initial task challenges them to spot the errors in a passage describing the structure and properties of this molecule. This reminds them of the bilayer arrangement, with the hydrophilic phosphate heads protruding outwards into the aqueous solutions on the inside and the outside of the cell. In a link to some upcoming lessons on the transport mechanisms, the students will learn that only small, non-polar molecules can move by simple diffusion and that this is through the tails of the bilayer. This introduces the need for transmembrane proteins to allow large or polar molecules to move into the cell by facilitated diffusion and active transport. Proteins that act as receptors as also introduced and an opportunity is taken to make a link to an upcoming topic so that students can understand how hormones or drugs will bind to target cells in this way. Moving forwards, the structure of cholesterol is covered and students will learn that this hydrophobic molecule sits in the middle of the tails and therefore acts to regulate membrane fluidity. The final part of the lesson challenges the students to apply their newly-acquired knowledge to a series of questions where they have to explain why proteins may have moved when two cells are used and to suggest why there is a larger proportion of these proteins in the inner mitochondrial membrane than the outer membrane.

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.

This lesson describes the movement across cell membranes by simple and facilitated diffusion and describes how the rate is increased. The PowerPoint and accompanying resources have been designed to cover the second part of specification point 2.3 of the AQA A-level Biology course and the limitations imposed by the phospholipid bilayer and the role of channel and carrier proteins are described in detail. The structure and properties of cell membranes was covered in the previous lesson so this one has been written to include continual references to the content of these lessons. This enables links to be made between the movement across a cell membrane with the concentration gradient, the parts of the membrane that are involved and any features that may increase the rate at which the molecules move. A series of questions about the alveoli are used to demonstrate how a large surface area, a short diffusion distance and the maintenance of a steep concentration gradient will increase the rate of simple diffusion. One of two quick quiz rounds is then used to introduce temperature and size of molecule as two further factors that can affect simple diffusion. The remainder of the lesson focuses on facilitated diffusion and describes how transmembrane proteins are needed to move small, polar or large molecules from a high concentration to a lower concentration across a partially permeable membrane.

This lesson describes the relationship between the structure and function of the vacuole, chloroplast and cell wall, as found in plant cells. Additional structures, such as the nucleus and mitochondria, were covered in the previous lesson on the structure of eukaryotic animal cells and the detailed content of these two lessons has been designed in parallel to cover the main content of point 2.1.1 of the AQA A-level Biology specification. The lesson begins with a task called REVERSE GUESS WHO which will challenge the students to recognise a cell structure from a description of its function. This will remind students that plant cells are eukaryotic and therefore contain a cell-surface membrane, a nucleus (+ nucleolus), a mitochondria, a Golgi apparatus, ribosomes and rough and smooth endoplasmic reticulum like the animal cells. Moving forwards, the rest of the lesson focuses on the relationship between the structure and function of the vacuole, chloroplast and cellulose cell wall. When considering the vacuole, key structures such as the tonoplast are described as well as critical functions including the maintenance of turgor pressure. A detailed knowledge of the structure of the chloroplast at this early stage of their A-level studies will increase the likelihood of a clear understanding of photosynthesis when covered in topic 5. For this reason, time is taken to consider the light-dependent and light-independent reactions and to explain how these stages are linked. The final part of the lesson challenges the students on their knowledge of cellulose as a polysaccharide as previously covered in topic 1. In addition to the focus on plant cells, the presence of chloroplasts and a cell wall in algae and the latter in fungi is also described. The previous lesson which contains the content that ties in closely with this one has been uploaded under the title “Structure of eukaryotic (animal) cells”

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 fully-resourced lesson explores the contributions of the chromosome mutations that arise during meiosis to genetic variation. The engaging PowerPoint and accompanying worksheets have been designed and written to cover the part of point 4.3 of the AQA A-level Biology specification which states that students should be able to describe how mutations in the numbers of chromosomes can arise spontaneously and significantly contribute to evolution. Over the course of the lesson, students will encounter a number of chromosome mutations but the main focus is chromosome non-disjunction and they will learn that this can result in Down, Turner’s and Klinefelter’s syndromes. Students are guided through a description of the formation of gametes and zygotes with abnormal numbers of chromosomes before being challenged to describe the formation of a zygote with Turner’s syndrome. The key aspects of meiosis, which are taught in a future lesson, are introduced and related to the lead up to the change in chromosome number. Inversion, translocation, duplication and deletion are also introduced and links are made to other topics such as regulatory sequences and gene expression.

This 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 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 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 fully-resourced lesson looks at the details of glycolysis as the first stage of aerobic and anaerobic respiration and explains how the sequence of reactions results in glucose being converted to pyruvate. The engaging PowerPoint and accompanying differentiated resources have been designed to cover the second part of point 5.2 of the AQA A-level Biology specification which states that students should know glycolysis as the phosphorylation of glucose and the production and subsequent oxidation of triose phosphate. The lesson begins with the introduction of the name of the stage and then explains how the phosphorylation of the hexoses and the production of the ATP, coenzymes and pyruvate are the stages that need to be known for this specification. Time is taken to go through each of these stages and key points such as the use of ATP in phosphorylation are explained so that students can understand how this affects the net yield. A quick quiz competition is used to introduce NAD and the students will learn that the reduction of this coenzyme, which is followed by the transport of the protons and electrons to the cristae for the electron transport chain is critical for the overall production of ATP. Understanding checks, in a range of forms, are included throughout the lesson so that students can assess their progress and any misconceptions are immediately addressed. This lesson has been written to tie in with the other uploaded lessons on anaerobic respiration and the different stages of aerobic respiration (the Link reaction, Krebs cycle and oxidative phosphorylation)

This fully-resourced lesson is clear and concise and has been written to explain how the inheritance of two or more genes that have loci on the same chromosome demonstrates linkage. The engaging PowerPoint and associated resource have been designed to cover point 3.8 (i and ii) of the Pearson Edexcel A-level Biology (Salters Nuffield) specification which states that students should know the meaning of a gene locus and understand the linkage of genes on a chromosome. 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.