A Science teacher by trade, I've also been known to be found teaching Maths and PE! However, strange as it may seem, my real love is designing resources that can be used by other teachers to maximise the experience of the students. I am constantly thinking of new ways to engage a student with a topic and try to implement that in the design of the lessons.
A Science teacher by trade, I've also been known to be found teaching Maths and PE! However, strange as it may seem, my real love is designing resources that can be used by other teachers to maximise the experience of the students. I am constantly thinking of new ways to engage a student with a topic and try to implement that in the design of the lessons.
A highly engaging and information lesson presentation (46 slides) which guides students through the steps needed to construct an accurate distance-time graph and then teaches them how to interpret the motions that are shown by the different lines. The lesson challenges the students to work out the type of graph that should be used to present the data and to suggest which factor from the blank table should go on the x-axis. Using the results that they obtain, a step-by-step guide is used to walk students through constructing the graph. This includes deciding on scales to ensure they are even and make the most of the available paper. Student will see the four key terms of motion associated with these graphs (acceleration, deceleration, constant speed and stationary) and will be able to use their graph to work out which lines go with which motion. Moving forwards, students will be shown how to calculate speed from the graph. There are progress checks throughout the lesson so that students can assess their understanding of the topic.
This lesson has been designed for GCSE students but is perfectly suitable for KS3 students too.
This fully-resourced lesson provides examples of anatomical, behavioural and physiological adaptations of organisms to their environment. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 4.19 in unit 2 of the Edexcel International A-level Biology specification and also describes the concept of a niche and makes continual links to related topics such as natural selection
A quick quiz competition at the start of the lesson introduces the different types of adaptation and a series of tasks are used to ensure that the students can distinguish between anatomical, behavioural and physiological adaptations. The Marram grass is used to test their understanding further, before a step by step guide describes how the lignified cells prevent a loss of turgidity. Moving forwards, the students are challenged to explain how the other adaptations of this grass help it to survive in its environment. A series of exam-style questions on the Mangrove family will challenge them to make links to other topics such as osmosis and the mark schemes are displayed to allow them to assess their understanding. The final part of the lesson focuses on the adaptations of the anteater but this time links are made to the upcoming topic of taxonomy so that students are prepared for this lesson on species and classification hierarchy.
This lesson describes the adaptations of gas exchange surfaces in single-celled organisms, insects, bony fish and dicotyledonous plants. The PowerPoint and accompanying worksheets are part of the first lesson in a series of 6 lessons that have been designed to cover the detail of point 3.2 (Gas exchange) of the AQA A-level Biology specification.
The lesson has been intricately planned to challenge the students on their understanding of the surface area to volume ratio (as covered in the previous lesson) and to make direct links to upcoming lessons on gas exchange and transport systems in humans. The lesson begins by explaining that single-celled organisms are able to diffuse oxygen and carbon dioxide across their body surface but that as organisms increase in size and their SA/V ratio decreases, they need adaptations at their gas exchange surfaces to be able to obtain the oxygen to meet their metabolic demands. This leads into the next part of the lesson which describes the roles of the following structures in insects and bony fish:
spiracles, tracheae, tracheoles and tracheole fluid
operculum, gill arch, gill filaments and lamellae
The next task challenges the students to use their knowledge of topics 1 and 2 to come up with the letters that form the key term, countercurrent flow. This is a key element of the lesson and tends to be a principle that is poorly understood, so extra time is taken to explain the importance of this mechanism. Students are shown two diagrams, where one contains a countercurrent system and the other has the two fluids flowing in the same direction, and this is designed to support them in recognising that this type of system ensures that the concentration of oxygen is always higher in the oxygenated water than in the blood in the lamellae.
The final part of the lesson describes the role of the stomata and the mesophyll cells in the gas exchange of a dicotyledonous plant. Students will learn that guard cells contain chloroplasts which generate ATP and then they are challenged to order a series of statements to form a description of the events that result in the opening of the stomata. The differing structures of the spongy mesophyll and palisade mesophyll cells are then considered before the students are challenged to explain how carbon dioxide moves through the leaf after entering via the stomata and then how water vapour and oxygen leave. Clear links are made to the loss of water vapour by transpiration so students are prepared for the lessons covering this biological process later in topic 3.
This lesson describes the role of the cardiovascular control centre in the medulla oblongata in the control of heart rate. The engaging and detailed PowerPoint and accompanying resources have been designed to cover the first part of point 7.13 (ii) of the Edexcel International A-level Biology specification and explains how this regulation enables the rapid delivery of oxygen and the removal of carbon dioxide.
This lesson begins with a prior knowledge check where students have to identify and correct any errors in a passage about the conduction system of the heart. This allows the SAN to be recalled as this structure play an important role as the effector in this control system. Moving forwards, the three key parts of a control system are recalled as the next part of the lesson will specifically look at the range of sensory receptors, the coordination centre and the effector. Students are introduced to chemoreceptors and baroreceptors and time is taken to ensure that the understanding of the stimuli detected by these receptors is complete and that they recognise the result is the conduction of an impulse along a neurone to the brain. A quick quiz is used to introduce the medulla oblongata as the location of the cardiovascular centre. The communication between this centre and the SAN through the autonomic nervous system can be poorly understood so detailed explanations are provided and the sympathetic and parasympathetic divisions compared. The final task challenges the students to demonstrate and apply their understanding by writing a detailed description of the control and this task has been differentiated three ways to allow differing abilities to access the work
The Pearson Edexcel A-level Biology A (Salters Nuffield) specification states that a minimum of 10% of the marks across the assessment papers will require the use of mathematical skills. This revision lesson has been designed to include a wide range of activities that challenge the students on these exact skills because success in the maths in biology questions can prove the difference between one grade and the next!
Step-by-step guides are used to walk students through the application of a number of the formulae and then exam-style questions with clear mark schemes (which are included in the PowerPoint) will allow them to assess their progress. Other activities include differentiated tasks, group discussions and quick quiz competitions such as “FROM NUMBERS 2 LETTERS” and “YOU DO THE MATH”.
The lesson has been written to cover as much of the mathematical requirements section of the specification as possible but the following have been given particular attention:
Hardy-Weinberg equation
Chi-squared test
Calculating size
Converting between quantitative units
Standard deviation
Estimating populations of sessile and motile species
Percentages and percentage change
Cardiac output
Geometry
Due to the detail and extensiveness of this lesson, it is estimated that it will take in excess of 2/3 hours of A-level teaching time to work through the activities and it can be used throughout the duration of the course
This lesson is fully-resourced, engaging and detailed and explains how the Contact process is one of the 3 steps involved in making sulfuric acid. The PowerPoint and accompanying resources, which are differentiated, have been written to cover point C6.1(d) of the OCR Gateway A GCSE Chemistry specification.
The lesson begins with a challenge where students have to use the 1st letters of the answers to questions on previously covered topics to come up with the word CONTACT. At this point, the students are introduced to the contact process as the 2nd step in a 3 stage process to make sulfuric acid. The lesson goes through the details of each of the 3 steps but particular time is spent exploring the conditions needed for the contact process in step 2. Students are continuously tested on their knowledge of reversible reactions and the key concepts to do with equilibrium position and equilibrium yield are explained so they can understand how the conditions of 2 atmospheres and 450 degrees celsius are chosen. Again through a prior knowledge check of empirical formula, the students will be introduced to vanadium oxide as the catalyst. As well as exam-style questions with displayed answers to check on current understanding, there are discussion points as well as quick quiz competitions to introduce key terms and values in a memorable way.
This fully-resourced lesson describes how magnification and resolution can be achieved using light and electron microscopy. The engaging PowerPoint and accompanying resources have been designed to cover the content of points 3.7 (i) & (ii) of the Edexcel International A-level Biology specification and also considers how specimens are stained.
To promote engagement and focus throughout this lesson, the PowerPoint contains a quiz competition with 7 rounds. The quiz rounds found in this lesson will introduce the objective lens powers, the names of the parts of a light microscope and emphasise some of the other key terms such as resolution. The final round checks on their understanding of the different numbers that were mentioned in the lesson, namely the differing maximum magnifications and resolutions. Time is taken to explain the meaning of both of these microscopic terms so that students can recognise their importance when considering the organelles that were met earlier in topic 3. By the end of the lesson, the students will be able to explain how a light microscope uses light to form an image and will understand how electrons transmitted through a specimen or across the surface will form an image with a TEM or a SEM respectively.
This fully-resourced lesson describes how post-transcriptional changes to mRNA enable 1 gene to give rise to multiple proteins. The detailed PowerPoint and accompanying resources have been designed to cover point 3.19 of the Edexcel International A-level Biology specification.
The lesson begins with a knowledge recall as the students have to recognise the definition of a gene as a sequence of bases on a DNA molecule that codes for a sequence of amino acids in a polypeptide chain. This description was introduced in topic 2 and the aim of the start of the lesson is to introduce the fact that despite this definition, most of the nuclear DNA in eukaryotes doesn’t actually code for proteins. A quick quiz competition is then used to introduce exons as the coding regions within a gene before students are challenged to predict the name of the non-coding regions and then to suggest a function for these introns. Moving forwards, pre-mRNA as a primary transcript is introduced and students will learn that this isn’t the mature strand that moves off to the ribosome for translation. Instead, a process called splicing takes place where the introns are removed and the remaining exons are joined together. Another quick quiz round leads to an answer of 20000 and students will learn that this is the number of protein-coding genes in the human genome. Importantly, the students are then told that the number of proteins that are synthesised is much higher than this value and a class discussion period encourages them to come up with biological suggestions for this discrepancy between the two numbers. The lesson concludes with a series of understanding and application questions where students will learn that alternative splicing enables a gene to produce more than a single protein and that this natural phenomenon greatly increases biodiversity.
This lesson describes the roles of glycolysis in aerobic and anaerobic respiration and links to the upcoming lessons on the link reaction and lactate formation. The engaging PowerPoint and accompanying resources have been designed to cover point 7.2 as detailed in the Edexcel International A-level Biology specification and includes details of the phosphorylation of the hexoses, the production of ATP by substrate-level phosphorylation, reduced NAD, pyruvate and lactate
The lesson begins with the introduction of the name of the stage and then explains how the phosphorylation of the hexoses, the breakdown into GP and the production of the ATP, reduced 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 describes the similarities and differences between the structure, position and function of the xylem, phloem and the sclerenchyma fibres. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 4.5 in unit 2 of the Edexcel International A-level Biology specification.
The lessons begins by challenging the students to identify the substances that a plant needs for the cellular reactions, where they are absorbed and where these reactions occur in a plant. The aim of this task is to get the students to recognise that water and mineral ions are absorbed in the roots and needed in the leaves whilst the products of photosynthesis are in the leaves and need to be used all over the plant. Students will be reminded that the xylem and phloem are part of the vascular system responsible for transporting these substances and then the rest of the lesson focuses on linking structure to function. A range of tasks which include discussion points, exam-style questions and quick quiz rounds are used to describe how lignification results in the xylem as a hollow tube of xylem cells to allow water to move as a complete column. They will also learn that the narrow diameter of this vessel allows capillary action to move water molecules up the sides of the vessel. The same process is used to enable students to understand how the structures of the companion cells allows assimilates to be loaded before being moved to the sieve tube elements through the plasmodesmata.
The final part of the lesson introduces the sclerenchyma tissue as part of the vascular bundle and along with the structure and function, the students will observe where this tissue is found in the stem in comparison to the xylem and phloem.
It is estimated that it will take in excess of 2 hours of A-level teaching time to cover the detail which has been written into this lesson
This detailed lesson describes the roles of the link reaction and the Krebs cycle in the complete oxidation of glucose which occur in the mitochondrial matrix. The PowerPoint and the accompanying resource have been designed to cover point 7.3 of the Edexcel International A-level Biology specification and includes descriptions of the formation of carbon dioxide, ATP, reduced NAD and FAD
The lesson begins with a challenge, where the students have to recall the details of glycolysis in order to form the word matrix. This introduces the key point that these two stages occur in this part of the mitochondria and time is taken to explain why the reactions occur in the matrix as opposed to the cytoplasm like glycolysis. Moving forwards, the Link reaction is covered in 5 detailed bullet points and students have to add the key information to these points using their prior knowledge as well as knowledge provided in terms of NAD. The students will recognise that this reaction occurs twice per molecule of glucose and a quick quiz competition is used to test their understanding of the numbers of the different products of this stage. This is just one of the range of methods that are used to check understanding and all answers are explained to allow students to assess their progress. The rest of the lesson focuses on the Krebs cycle. In line with the detail of the specification, students will understand how decarboxylation and dehydrogenation reactions result in the regeneration of the oxaloacetate
This fully-resourced lesson describes the meaning of the terms stem cell, pluripotency, totipotency, morula and blastocyst. The PowerPoint and accompanying worksheets have been designed to cover points 3.17 (i) and (ii) of the Edexcel International A-level Biology specification and contains discussions about the decisions that the scientific community have to make about the use of stem cells in medical therapies.
The lesson begins with a knowledge recall of the structure of eukaryotic cells and the students have to use the first letters of each of the four answers to reveal the key term, stem cell. Time is then taken to consider the meaning of cellular differentiation, and this leads into the key idea that not all stem cells are equal when it comes to the number of cell types that they have the potential to differentiate into. A quick quiz round introduces the five degrees of potency, and then the students are challenged to use their understanding of terminology to place totipotency, pluripotency, multipotency, oligopotency and unipotency in the correct places on the potency continuum. Although the latter three do not have to be specifically known based on the content of specification point 3.17 (i), an understanding of their meaning was deemed helpful when planning the lesson as it should assist with the retention of knowledge about totipotency and pluripotency. These two highest degrees of potency are the main focus of the lesson, and key details are emphasised such as the ability of totipotent cells to differentiate into any extra-embroyonic cell, which the pluripotent cells are unable to do. The morula, and inner cell mass and trophoblast of the blastocyst are then introduced and used to demonstrate these differences in potency. The final part of the lesson discusses the decisions that the scientific community have to make about the use of embryonic stem cells, adult stem cells and also foetal stem cells which allows for a link to chorionic villus sampling from topic 2.
There is also a Maths in a Biology context question included in the lesson (when introducing the morula) to ensure that students continue to be prepared for the numerous calculations that they will have to tackle in the terminal exams. This resource has been differentiated two ways to allow students of differing abilities to access the work
This lesson describes classification as a means of organising the variety of life based on relationships between organisms. The engaging PowerPoint and accompanying resource have been designed to cover point 4.14 (i) of the Edexcel International A-level Biology specification and focuses on the classification hierarchy where species is the lowest taxon but also describes the binomial naming system which uses the genus and species. The lesson also contains links to the next lesson where molecular phylogeny is described and the three-domain system is covered in greater detail with a focus on the results of Carl Woese’s rRNA study
The lesson begins by looking at the meaning of a population in Biology so that the term species can be introduced. A hinny, which is the hybrid offspring of a horse and a donkey, is used to explain how these two organisms must be members of different species because they are unable to produce fertile offspring. Moving forwards, students will learn that classification is a means of organising the variety of life based on relationships between organisms using differences and similarities in phenotypes and in genotypes and is built around the species concept and that in the modern-day classification hierarchy, species is the lowest taxon. A quiz runs throughout the lesson and this particular round will engage the students whilst they learn (or recall) the names of the other 7 taxa and the horse and the donkey from the earlier example are used to complete the hierarchy. Students will understand that the binomial naming system was introduced by Carl Linnaeus to provide a universal name for each species and they will be challenged to apply their knowledge by completing a hierarchy for a modern-day human, by spotting the correct name for an unfamiliar organism and finally by suggesting advantages of this system.
This fully-resourced lesson looks at the use of electrocardiograms to aid the diagnosis of abnormal heart rhythms. The engaging PowerPoint and accompanying resources have been designed to cover point 7.12 (iii) of the Edexcel International A-level Biology specification but also can be used as a revision lesson as the students are challenged on their prior knowledge of the cardiac cycle and heart structure as covered in topic 1.
The lesson has been written to take place in an imaginary cardiology ward where the students are initially challenged on their knowledge of the symptoms and risk factors of CVD before looking at testing through the use of ECGs and diagnosis. The main focus of the lesson is the ECG and a quiz competition is used to introduce the reference points of P, QRS and T before time is taken to explain their representation with reference to the cardiac cycle. Moving forwards, a SPOT the DIFFERENCE task is used to challenge the students to recognise differences between sinus rhythm and some abnormal rhythms including tachycardia and atrial fibrillation. Bradycardia is used as a symptom of sinus node disfunction and the students are encouraged to discuss this symptom along with some others to try to diagnose this health problem.
This lesson has been designed to tie in with the lesson that covers the previous specification point on the normal electrical activity of the heart and the myogenic nature of cardiac muscle
This detailed and engaging lesson covers the detail of specification points 5.1.4 (c and d) of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply an understanding of the histology of the pancreas and the control of insulin secretion. There is a particular emphasis on structure throughout the lesson so that students can recognise the exocrine and endocrine tissues of the pancreas as well as describe their specific functions.
The lesson begins with a list of endocrine glands and the students are challenged to select the gland which also has exocrine functions. This leads into a focus on the exocrine tissues of the pancreas, beginning with the enzymes that are secreted and form pancreatic juice. Students will discover how groups of these cells are called acini and the secretion of the enzymes into the lobule at the centre will lead to the intralobular ducts and finally the formation of the pancreatic duct. Moving forwards, students are introduced to the Islets of Langerhans and the specialised alpha and beta cells that are found within this endocrine tissue. The rest of this lesson looks at how the release of insulin from the beta cells is controlled. Some of the structures and substances involved have been met in earlier topics so a fun quiz round is used to see which students can recall these parts first. A series of questions and discussion points challenge the students to verbalise answers and to discuss key points so that the cascade of events that take place in the lead up to the release can be considered. In the final task, students have to describe these events in detail and this task has been differentiated so that students of differing abilities can access the work.
This lesson has been specifically designed for students on the OCR A-level Biology A course and ties in well with the other lessons from module 5.1.4 on the control of blood glucose concentration and diabetes mellitus type I and II
This fully-resourced lesson describes the structure of the cell surface membrane and references Singer and Nicholson’s fluid mosaic model. The detailed and engaging PowerPoint and accompanying resources have been designed to cover specification point 4.2 (i) of the Edexcel A-level Biology B specification and also makes clear links are made to related topics such as the binding of hormones as covered in topic 9 and the electron transport chain as covered in topic 5.
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 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 topic 9 so that students can understand how hormones or drugs will bind to target cells in this way and cause the release of cAMP on the interior of the cell. 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 detailed lesson has been planned to cover the 1st part of specification point 6.4.3 of the AQA A-level Biology specification which states that students should be able to describe the detailed structure of the nephron and understand its role in ultrafiltration, selective reabsorption and osmoregulation. The lesson was designed at the same time as the other lessons in this topic on ultrafiltration, selective reabsorption and osmoregulation so that a common theme runs throughout and students can build up their knowledge gradually in order to develop a deep understanding of this organ.
Students will come to recognise the renal cortex and renal medulla as the two regions of the kidney and learn the parts of the nephron which are found in each of these regions. Time is taken to look at the vascular supply of this organ and specifically to explain how the renal artery divides into the afferent arterioles which carry blood towards the glomerulus and the efferent arterioles which carry the blood away. The main task of the lesson challenges the students to relate structure to function. Having been introduced to the names of each of the parts of the nephron, they have to use the details of the structures found at these parts to match the function. For example, they have to make the connection between the microvilli in the PCT as a sign that this part is involved in selective reabsorption.
This lesson has been designed for students studying on the AQA A-level Biology course
This lesson describes the overall reaction of aerobic respiration, introducing the 4 stages before the finer details are covered in the upcoming lessons. The engaging PowerPoint and accompanying resource have been designed to cover points 7.1 (i) and (ii) of the Edexcel International A-level Biology specification and explains how each step in this many-stepped process is catalysed by a specific intracellular enzyme.
The lesson begins with an introduction to glycolysis and students will learn how this first stage of aerobic respiration is also the first stage when oxygen is not present. This stage involves 10 reactions and an opportunity is taken to explain how each of these reactions is catalysed by a different, specific intracellular enzyme. A version of “GUESS WHO” challenges students to use a series of structural clues to whittle the 6 organelles down to just the mitochondrion so that they can learn how the other three stages take place inside this organelle. Moving forwards, the key components of the organelle are identified on a diagram. Students are introduced to the stages of respiration so that they can make a link to the parts of the cell and the mitochondria where each stage occurs. Students will learn that the presence of decarboxylase and dehydrogenase enzymes in the matrix along with coenzymes and oxaloacetate allows the link reaction and the Krebs cycle to run and that these stages produce the waste product of carbon dioxide. Finally, time is taken to introduce the electron transport chain and the enzyme, ATP synthase, so that students can begin to understand how the flow of protons across the inner membrane results in the production of ATP and the the formation of water when oxygen acts as the final electron acceptor.
This lesson describes how the electron transport chain and the chemiosmosis are involved in the synthesis of ATP by oxidative phosphorylation. The PowerPoint has been designed to cover point 7.4 of the Edexcel International A-level Biology 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 specifically written to tie in with the other uploaded lessons on glycolysis, the link reaction and Krebs cycle.
This lesson describes how the surfaces in insects, fish and mammals are adapted for gas exchange. The PowerPoint and accompanying worksheets have been designed to cover the detail of point 4.3 (i) of the Edexcel A-level Biology B specification.
The lesson has been intricately planned to challenge the students on their understanding of the surface area to volume ratio (as covered in topic 4.1) and to make direct links to upcoming lessons on the transport systems in humans. The lesson begins by explaining that single-celled organisms are able to diffuse oxygen and carbon dioxide across their body surface but that as organisms increase in size and their SA/V ratio decreases, they need adaptations at their gas exchange surfaces to be able to obtain the oxygen to meet their metabolic demands. This leads into the next part of the lesson which describes the roles of the following structures in insects and bony fish:
spiracles, tracheae, tracheoles and tracheole fluid
operculum, gill arch, gill filaments and lamellae
The next task challenges the students to use their knowledge of topics 1, 2 and 3 to come up with the letters that form the key term, countercurrent flow. This is a key element of the lesson and tends to be a principle that is poorly understood, so extra time is taken to explain the importance of this mechanism. Students are shown two diagrams, where one contains a countercurrent system and the other has the two fluids flowing in the same direction, and this is designed to support them in recognising that this type of system ensures that the concentration of oxygen is always higher in the oxygenated water than in the blood in the lamellae.
As the alveoli as a structure of gas exchange was introduced at GCSE, this final part of the lesson has been written to challenge the recall of that knowledge and to build on it.
The main focus is the type of epithelium found lining the alveoli and students will discover that a single layer of flattened cells known as simple, squamous epithelium acts to reduce the diffusion distance. Again, students will have met this in a lesson in topic 2 on specialised cells (and tissues) so a number of prior knowledge checks are used alongside current understanding checks.
The following features of the alveolar epithelium are also covered:
Surface area
Moist lining
Production of surfactant
The maintenance of a steep concentration gradient
As a constant ventilation supply is critical for the maintenance of the steep concentration gradient, the final task considers the mechanism of ventilation