This lesson describes how iPS cells are formed from fibroblasts and discusses why this method is less controversial than the use of embryonic stem cells. The PowerPoint and accompanying resources are part of the 2nd lesson in a series of 2 lessons which covers the content of point 7.3 (stem cells) of the Edexcel A-level biology B specification. The lesson begins with a SPOT THE ERRORS task, where students have to use their knowledge of pluripotent cells from the previous lesson to identify the 3 errors and make corrections. The aim of this task is to remind them that pluripotent cells are found in embryos and can divide in unlimited numbers before finally becoming fully differentiated somatic cells. Moving forwards, the students are introduced to fibroblasts as examples of these somatic cells and the opportunity is taken to challenge their knowledge of collagen as this is a substance produced by these cells. The answers are embedded into the PowerPoint to allow the students to assess their recall of this topic 1 content. A quick quiz is used to introduce the acronym iPS and students will learn that fibroblasts can be reprogrammed to form induced pluripotent cells using specific transcription factors. The remainder of the lesson challenges them to answer questions about the use of iPS cells in regenerative medicine after reading a passage about an example. This allows them to recognise that deriving these cells from adult tissues as opposed to embryonic stem cells raises less problems and the transplant into the same person reduces the risk of rejection.

This lesson has been designed to cover the content of the 1st part of specification point 6.1.2 of the AQA A-level Biology specification which states that students should know the basic structure of a Pacinian corpuscle and be able to use its function as a representation of sensory receptors. By the end of the lesson students will understand that sensory receptors respond to specific stimuli and how a generator potential is established. The lesson begins by using a quiz to get the students to recognise the range of stimuli which can be detected by receptors. This leads into a task where the students have to form 4 sentences to detail the stimuli which are detected by certain receptors and the energy conversion that happen as a result. Students will be introduced to the idea of a transducer and learn that receptors always convert to electrical energy which is the generator potential. The remainder of the lesson focuses on the Pacinian corpuscle and how this responds to pressure on the skin. The involvement of sodium and potassium ions is introduced so discussions on how the membrane potential changes from resting potential in the establishment of a generator potential are encouraged. This lesson has been written for students studying on the AQA A-level Biology course and ties in nicely with other uploaded lessons which cover the content of topic 6

This lesson describes the biological meaning of species, populations, gene pool and allele frequency and explains how these terms are linked. The PowerPoint and accompanying resources are part of the 1st lesson in a series of 2 lessons that cover the detail of specification point 7.2 (Populations) of the AQA A-level biology. The two living species of the African elephant, the forest and bush elephant, are used as examples to demonstrate the meaning of species and to show how they exist as one or more populations. A quick quiz introduces the term gene pool in an engaging way and then the allele frequency of three versions of the GBA gene demonstrates how these frequencies can change in small populations. In doing so, students are briefly introduced to genetic drift which they will encounter in an upcoming topic. The students are challenged throughout the lesson with understanding checks and prior knowledge checks as well as exam-based questions where they have to comment on the validity of a scientist’s conclusion. The other lesson in topic 7.2 is the Hardy-Weinberg principle.

A short lesson which includes a lesson presentation (27 slides) and a hint worksheet and looks at redox reactions that involve oxygen and electrons. When focussing on oxygen, the lesson uses the example of extracting metals by reacting them with carbon to show how the metal is reduced and the carbon is oxidised. Key terminology such as reducing agents are also discussed. The important topic of electrolysis is used when teaching about the redox reactions that involve electrons and students are reminded about half equations. This lesson has been designed for GCSE students (14 - 16 year olds in the UK) but is suitable for other ages

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 is a fast-paced lesson which goes through the main steps of selective breeding and looks at the potential risks of this process. The lesson begins by looking at the characteristics of a number of organisms that would be selected. Time is taken to ensure that students understand that selective breeding is not a new thing and has been going on for a very long time and therefore some of the problems associated with this are now being experienced. The actual process is reduced down into 5 steps which can be recalled and applied to questions. The remainder of the lesson looks at the potential issues with selective breeding. The reduction in the nose size of pugs is explored as an example of the health problems which bred animals may face. This lesson has been written for GCSE students.

This lesson describes how to prepare and examine microscope slides and the use of staining in light microscopy. The PowerPoint and accompanying resources have been designed to cover points 2.1.1 (b & c) of the OCR A-level Biology A specification and describe how the eyepiece graticule and stage micrometer are used to measure the size of an object with a light microscope and the use of eosin and methylene blue. The main task of this 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 and this will need them to convert between units. 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. In the last lesson, they were briefly introduced to the idea that some specimens need to be stained as light passes completely through transparent samples and the remainder of the lesson builds on this knowledge. Students will learn that cell populations, structures within cells and biological tissues can be distinguished using stains and a series of questions will challenge them to make links to biological molecules, organelles and infections. Links are also made to the upcoming topic of epithelial tissue in the respiratory system. This lesson has been specifically written to tie in with the previous lesson on light and electron microscopes and 2 rounds of the sub-module quiz competition are found in this lesson.

This lesson describes how communication occurs between cells by cell signalling. The PowerPoint and accompanying resource have been designed to cover point 5.1.1 (b) of the OCR A-level Biology A specification and focuses on the use of the nervous system for communication between the CNS and effectors and the release of hormones to bring about responses. As this is one of the first lessons to be delivered in module 5, this lesson has been specifically planned to prepare students for the upcoming topics of neuronal and hormonal communication. Students begin by learning that cell signalling governs the basic activities of cells and coordinates multiple cell actions. Moving forwards, the next part of the lesson focuses on the nervous system and students will learn that an electrical impulse will be conducted on a somatic or an autonomic motor neurone depending upon the type of muscle to be stimulated. This provides some introductory information for modules 5.1.3 and 5.1.5. The remainder of the lesson describes how the hormones that are secreted by the cells of endocrine glands allow communication with target cells and the different actions of peptide and steroid hormones is considered.

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.

Amino acids are the monomers of polypeptides and this lesson describes their structure and makes links to related topics such as genes and dipeptides. The engaging PowerPoint has been designed to cover the first part of point 1.4.1 of the AQA A-level Biology specification and provides a clear introduction to the following lesson on the formation of dipeptides and polypeptides. The lesson begins with a prior knowledge check, where the students have to use the 1st letters of 4 answers to uncover a key term. This 4-letter key term is gene and the lesson begins with this word because it is important for students to understand that these sequences of bases on DNA determine the specific sequence of amino acids in a polypeptide. Moving forwards, students are given discussion time to work out that there are 64 different DNA triplets and will learn that these encode for the 20 amino acids that are common to all organisms. The main task of the lesson is an observational one, where students are given time to study the displayed formula of 4 amino acids. They are not allowed to draw anything during this time but will be challenged with 3 multiple choice questions at the end. This task has been designed to allow the students to visualise how the 20 amino acids share common features in an amine and an acid group. A quick quiz round introduces the R group and time is taken to explain how the structure of this side chain is the only structural difference, before cysteine is considered in greater detail due to the presence of sulfur atoms. Students are briefly introduced to disulfide bridges so they will recognise how particular bonds form between the R groups in the tertiary structure which is covered in the next lesson. The lesson concludes with one more quiz round called LINK TO THE FUTURE where the students will see the roles played by amino acids in the later part of the course such as translation and mineral ions.

A whole lesson on the topic of active transport which includes a concise lesson presentation (20 slides) and a set of questions that are used to check on the students’ understanding. This lesson is designed for GCSE students (14 - 16 year olds in the UK) but could be used with A-level students who are covering the topic of movement across cell membranes. The main focus of the lesson is to get students to understand that this is an active process which moves substances against the concentration gradient and therefore needs energy for this process. The final part of the lesson looks at the different types of questions that can accompany this topic and a step-by-step guide is used to answer a difficult longer answer question as a class.

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 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

A fully-resourced lesson which includes a lesson presentation (24 slides) and a worksheet which is differentiated so that students can judge their understanding of the topic of writing half equations for electrolysis and access the work accordingly. The lesson uses worked examples and helpful hints to show the students how to write half equations at both the cathode and anode. Time is taken to remind students about the rules at the electrodes when the electrolyte is in solution so that they can work out the products before writing the equations. This lesson has been designed for GCSE students (14 - 16 years old in the UK) but could be used with older students.

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 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 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 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)

This lesson revisits the topic of random and systematic errors and also challenges students on other scientific skills such as identifying variables. Students tend to find this topic confusing, so the PowerPoint and accompanying resources have been designed to support them to identify whether an error is random or systematic and then to understand what to do next. The lesson guides the students through a series of real life examples and shows them how to spot each type of error. There is a considerable mathematical element to this lesson, including the calculation of means or missing values in a table. The lesson concludes with a series of exam-style questions where the students have to apply their understanding of identifying errors, variables and calculating means.

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.