This lesson describes the uses and implications of pre-implantation genetic diagnosis, amniocentesis and chorionic villus sampling. The lesson PowerPoint and accompanying worksheets have been primarily designed to cover point 2.17 of the Edexcel International A-level Biology specification but there are regular checks of their knowledge of the content of topic 2, where topics including monohybrid inheritance and cystic fibrosis are tested. The lesson begins by challenging them to use this prior knowledge of topic 2 to identify the letters in the abbreviations PGD and CVS. The involvement of IVF to obtain the embryos (or oocytes) is then discussed and a series of exam-style questions are used to get them to understand how this method screens embryos prior to implantation, so that those identified as having genetic diseases or being carriers are not inserted into the female’s uterus. Mark schemes for all of the questions included in this lesson are embedded into the PowerPoint so students can constantly assess their progress. Moving forwards, Down syndrome (trisomy 21) is used as an example of a chromosomal abnormality that can be tested for using CVS or amniocentesis. Time is taken to describe the key details of both of these procedures so students have a clear understanding of the implications and the invasiveness to the female being tested. The link between amniocentesis and an increased risk of miscarriage is considered and the results of a 2006 study are used to challenge them on their data skills.

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 how the standard deviation and the t-test are used to analyse data. The detailed PowerPoint and accompanying resources are part of the first lesson in a series of 2 lessons that have been designed to cover point 10.1 (vi) of the Edexcel A-level Biology B specification. The next lesson, which uses skills covered in this lesson and has also been uploaded, describes how to analyse data using the Spearman rank correlation coefficient A step by step guide walks the students through each stage of the calculation of the standard deviation and gets them to complete a worked example with the class before applying their knowledge to another set of data. This data looks at the birth weights of humans on one day in the UK and this is used again later in the lesson to compare against the birth weights of babies in South Asia when using the student’s t-test. The null hypothesis is re-introduced, as it will encountered when considering the chi squared test in topic 8, and students will learn to accept or reject this based upon a comparison of their value against one taken from the table based on the degrees of freedom.

This lesson describes the effects of pH on enzyme activity. The PowerPoint and accompanying resources are part of the first lesson in a series of 3 lessons which have been designed to cover the content of point 2.1.4 (d)(i)of the OCR A-level Biology A specification. The lesson begins with a short discussion, where the students are challenged to identify how the stomach and the small intestine differ in terms of a particular condition and to explain why the conditions in these neighbouring digestive organs are so important. This introduces pepsin and trypsin and these protease enzymes play a key role throughout the lesson as they are good examples of how different extracellular enzymes have different optimum pH values (which are not necessarily 7.0). Moving forwards, students will discuss how the rate of an enzyme-controlled reaction will change if there are small or large changes in pH, and then time is taken to ensure that students can explain these changes with reference to tertiary structure bonds and the shape of the active site. Through the use of a quick quiz competition, the students will be reminded of the key term “buffer” and a series of questions are used to challenge their understanding of how these substances could be used in a practical investigation. They will also learn how buffers are found in blood plasma as well as in red blood cells in the form of haemoglobin. With there being such a considerable proportion of marks for Maths in a Biology context questions in the A-level assessments, the remainder of the lesson challenges the students to use a given formula to calculate the pH of blood when given the hydrogen ion concentration and to calculate percentage decrease. These questions have been differentiated to give assistance to those that need the support Please note that this is a lesson which describes the effect on enzyme activity, as described in 2.1.4 (d)(i), and not the details of the practical investigation which is covered in a later lesson

This lesson describes the structure of DNA as a double-stranded polymer coiled into a double helix and focuses on nucleotides as the monomers. The PowerPoint and accompanying resources have been designed to cover the detail of point 3.4 of the Edexcel GCSE Biology & Combined Science specifications. The lesson begins with a reveal of the acronym DNA and students will learn that this stands for deoxyribonucleic acid. There is a focus on the use and understanding of key terminology throughout the lesson so time is taken to look at the meanings of the prefixes poly and mono as well as the suffix -mer. This leads into the description of DNA as a polymer which is made up of many monomers known as nucleotides. Students will be introduced to the three components of a DNA nucleotide and will learn that four different bases can be attached to the sugar. An observational task is used to get them to recognise that DNA consists of two strands and that complementary bases are joined by hydrogen bonds. Understanding checks are interspersed throughout the lesson along with mark schemes so that students can assess their progress

This fully-resourced lesson has been designed to cover both the foundation and higher tier content of specification point 5.3.2 (Control of blood glucose concentration) as found in topic 5 of the AQA GCSE Biology & Combined Science specifications. This resource contains an engaging PowerPoint (37 slides) and accompanying worksheets, some of which have been differentiated so that students of different abilities can access the work. The resource is filled with a wide range of activities, each of which has been designed to engage and motivate the students whilst ensuring that the key Biological content is covered in detail. Understanding checks are included throughout so that the students can assess their grasp of the content. In addition, previous knowledge checks make links to content from earlier topics such as the endocrine system and literacy checks ensure that the students can spell and recognise the key words, which is extremely important considering how many terms begin with the letter g in this homeostatic control system. The following content is covered in this lesson: The receptors, coordination centre and effectors in the control of blood glucose concentration The release of insulin when high blood glucose levels are detected The conversion of glucose to glycogen for storage in liver and muscle cells The causes and treatments of diabetes type I and II The release of glucagon when low blood glucose levels are detected The interaction of insulin and glucagon in a negative feedback cycle As stated at the top, this lesson has been designed for GCSE-aged students who are studying the AQA GCSE Biology or Combined Science courses, but it can be used with A-level students who need to go back over the key points before looking at the homeostatic control in more detail

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 engaging and fully-resourced lesson covers the content of specification points 5.1.4 (e and f) of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply an understanding of the differences between diabetes mellitus type I and II and the potential treatments of this disease. 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. The final part of the lesson looks at the potential treatments which include the genetic modification of bacteria. This topic is covered in greater detail in module 6.1.3 so this section of the lesson focuses on the enzymes involved as well as the plasmid DNA from a bacterial cell. This lesson has been designed for students studying the OCR A-level Biology A course and runs alongside the uploaded lesson on the control of blood glucose concentration as well as the other lessons that have been added for module 5.1.4

This fully-resourced lesson challenges students to identify environmental factors that limit the rate of photosynthesis. The PowerPoint and accompanying resources have been designed to cover the fourth part of point 5.1 of the AQA A-level Biology specification and focuses on light intensity, carbon dioxide concentration and temperature. The lesson has been specifically written to tie in with the three previous lessons in this topic which covered the structure of the chloroplast, the light-dependent reactions and the light-independent reactions. Exam-style questions are included throughout the lesson and these require the students to explain why light intensity is important for both reactions as well as challenging them on their ability to describe how the relative concentrations of GP, TP and RuBP would change as carbon dioxide concentration decreases. There are also links to previous topics such as enzymes when they are asked to explain why an increase in temperature above the optimum will limit the rate of photosynthesis. Step by step guides are included to support them to form some of the answers and mark schemes are always displayed so that they can quickly assess their understanding and address any misconceptions.

This fully-resourced lesson describes the ultrastructure of a prokaryotic cell and the function of the structures found in these cells. The engaging PowerPoint and accompanying resources have been designed to cover specification point 3.5 (i) & (ii) as detailed in the Edexcel International A-level Biology specification and also compares these cells against the eukaryotic cells that were met in the previous lesson. A clear understanding of terminology is important for A-level Biology so this lesson begins with a challenge, where the students have to recognise a prefix that they believe translates as before or in front of . This leads into the discovery of the meaning of prokaryote as before nucleus and this acts to remind students that these types of cell lack this cell structure. Links to the previous lessons on the eukaryotic cells are made throughout the lesson and at this particular point, the students are asked to work out why the DNA would be described as naked and to state where it will be found in the cell. Moving forwards, the students will discover that these cells also lack membrane bound organelles and a quick quiz competition challenges them to identify the specific structure that is absent from just a single word. In addition to the naked DNA, students will learn that there are also ribosomes in the cytoplasm and will discover that these are smaller than those found in the cytoplasm of an eukaryotic cell (but the same size as those in chloroplasts and mitochondria). The remainder of the lesson focuses on the composition of the cell wall, the additional features of prokaryotic cells such as plasmids and there is also the introduction of binary fission as the mechanism by which these organisms reproduce

This fully-resourced lesson describes how evolution can come through natural selection and acts on variation to bring about adaptations. The PowerPoint and accompanying resources have been designed to cover specification points 3.2 (i) & (ii) of the Edexcel A-level Biology B specification and considers a range of different behavioural, anatomical and physiological adaptations. President Trump’s error ridden speech about antibiotics is used at the beginning of the lesson to remind students that this is a treatment for bacterial infections and not viruses as he stated. 2 quick quiz competitions are used to introduce MRSA and then to get the students to recognise that they can use this abbreviation to remind them to use mutation, reproduce, selection (and survive) and allele in their descriptions of evolution through natural selection. The main task of the lesson challenges the students to form a description that explains how this strain of bacteria developed resistance to methicillin to enable them to see the principles of natural selection. This can then be used when describing how the anatomy of the modern-day giraffe has evolved over time. The concept of convergent evolution is introduced and links are made to the need for modern classification techniques. Moving forwards, students will understand how natural selection leads to adaptations and a quick quiz competition 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. The final part of the lesson focuses on the adaptations of the anteater and links are made to the topic of classification hierarchy which was covered at the start of topic 3… Due to the extensiveness of this lesson and the detail contained within the resources, it is estimated that it will take in excess of 2 hours of allocated A-level teaching time to deliver this lesson.

This fully-resourced lesson describes how reproductive isolation can lead to allopatric and sympatric speciation. The engaging PowerPoint and accompanying resources have been designed to cover point 3.2 (iii) of the Edexcel A-level Biology B specification. The lesson begins by using the example of a hinny, which is the hybrid offspring of a horse and a donkey, to challenge students to recall the biological classification of a species. Moving forwards, students are introduced to the idea of speciation and the key components of this process, such as isolation and selection pressures, are covered and discussed in detail. Understanding and prior knowledge checks are included throughout the lesson to allow the students to not only assess their progress against the current topic but also to make links to earlier topics in the specification. Time is taken to look at the details of allopatric speciation and how the different mutations that arise in the isolated populations and genetic drift will lead to genetic changes. The example of allopatric speciation in wrasse fish because of the isthmus of Panama is used to allow the students to visualise this process. The final part of the lesson considers sympatric speciation and again a wide variety of tasks are used to enable a deep understanding to be developed.

This lesson describes and explains how increasing the concentration of inhibitors affects the rate of an enzyme-controlled reaction. The PowerPoint and accompanying resource are the last in a series of 5 lessons which cover the content detailed in point 1.4.2 of the AQA A-level Biology specification and describes the effect of both competitive and non-competitive inhibitors. The lesson begins with a made up round of the quiz show POINTLESS called “Biology opposites” and this will get the students to recognise that inhibition is the opposite of stimulation. This introduces inhibitors as substances that reduce the rate of a reaction and students are challenged to use their general knowledge of enzymes to identify that inhibitors prevent the formation of the enzyme-substrate complex. Moving forwards, a quick quiz competition generates the abbreviation EIC (representing enzyme-inhibitor complex) and this introduces competitive inhibitors as substances that occupy the active site. The students are asked to apply their knowledge to a new situation to work out that these inhibitors have a similar shape to the enzyme’s substrate molecule. A series of exam-style questions are used throughout the lesson and at this point, the students are challenged to work out that an increase in the substrate concentration would reduce the effect of a fixed concentration of a reversible competitive inhibitor. The rest of the lesson focuses on non-competitive inhibitors and time is taken to ensure that key details such as the disruption of the tertiary structure is understood and biological examples are used to increase the relevance. Again, students will learn that increasing the concentration of the inhibitor results in a greater inhibition and a reduced rate of reaction but that increasing the substrate concentration cannot reduce the effect as was observed with competitive inhibitors.

This lesson describes how the immune system uses molecules on the surface of a cell to identify it, focusing on the identification of pathogens by their antigens. The PowerPoint and accompanying resources which are differentiated are part of the 1st lesson in the series of 7 that cover the content detailed in topic 2.4 of the AQA A-level Biology specification. As this is the first lesson in topic 2.4, it has been specifically planned to introduce a number of key concepts which include phagocytosis, T and B cells, antibodies and memory cells so that students are prepared for upcoming lessons. The lesson begins by challenging the students to use their knowledge of cells to recall the common internal components of a cell before they are informed that all cells also have molecules on their outer membrane. Students will recognise that these molecules are used by the immune system for identification before a quick quiz competition reveals that this allows toxins, abnormal body cells and pathogens to be identified. Moving forwards, the next part of the lesson focuses on the antigens that are found on the outside of a pathogen and links are made to upcoming lesson topics which include: phagocytosis following the identification of a pathogen antigen-presentation by macrophages and dendritic cells production of antibodies which are specific to the antigens the use of antigens in a vaccination program The final task challenges the students to describe and explain how antigen variability will affect disease and disease prevention and this task has been differentiated two ways to allow students of differing abilities to be challenged and supported.

This lesson describes the mode of actions of macrophages, neutrophils and lymphocytes. The engaging PowerPoint and accompanying resource have been primarily designed to cover point 6.7 (i) of the Edexcel A-level Biology B specification but includes an introduction to antigen-presentation so that the students are prepared for upcoming lessons on the cell-mediated and humoral responses. At the start of the lesson, the students are challenged to recall that cytosis is a suffix associated with transport mechanisms and this introduces phagocytosis as a form of endocytosis which takes in pathogens and foreign particles. This emphasis on key terminology runs throughout the course of the lesson and students are encouraged to consider how the start or end of a word can be used to determine meaning. The process of phagocytosis is then split into 5 key steps and time is taken to discuss the role of opsonins as well as the fusion of lysosomes and the release of lysozymes. A series of application questions are used to challenge the students on their ability to make links to related topics including an understanding of how the hydrolysis of the peptidoglycan wall of a bacteria results in lysis. Students will be able to distinguish between neutrophils and monocytes from a diagram and at this point, the role of macrophages and dendritic cells as antigen-presenting cells is described so that it can be used in the next lesson. The lesson concludes with an introduction to lymphocytes so that initial links between phagocytosis and the specific immune responses are made.

This lesson describes the role of the hypothalamus and the mechanisms of thermoregulation that maintain the body in dynamic equilibrium during exercise. The PowerPoint has been designed to cover point 7.12 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification. Students were introduced to homeostasis at GCSE and this lesson has been written to build on that knowledge and to add the key detail needed at this level. Focusing on the three main parts of a homeostatic control system, the students will learn about the role of the internal and peripheral thermoreceptors, the thermoregulatory centre in the hypothalamus and the range of effectors which bring about the responses to restore optimum levels. The following responses are covered in this lesson: Vasodilation Increased sweating Body hairs In each case, time is taken to challenge students on their ability to make links to related topics such as the arterioles involved in the redistribution of blood and the high specific latent heat of vaporisation of water.

This lesson describes and explains how production is affected by a range of farming practices designed to increase the efficiency of energy transfer. The PowerPoint and accompanying resources are part of the third lesson in a series of 3 which have been designed to cover the detail included in specification point 5.3 of the AQA A-level Biology specification. Over the course of the lesson, a range of tasks which include exam-style questions with displayed mark schemes, guided discussion periods and quick quiz competitions will introduce and consider the following farming practices: raising herbivores to reduce the number of trophic levels in a food chain intensely rearing animals to reduce respiratory losses in human food chains the use of fungicides, insecticides and herbicides the addition of artificial fertilisers The ethical issues raised by these practices are also considered and alternative methods discussed such as the addition of natural predators and the use of organic fertilisers like manure As this is the last lesson in topic 5.3, it has been specifically planned to challenge the students on their knowledge of the previous two lessons and this includes a series of questions linking farming practice to the formula to calculate net production

This detailed lesson describes how the ventilation rate is controlled by the ventilation centre in the medulla oblongata. The engaging PowerPoint and accompanying resource have been designed to cover the second part of point 7.13 (ii) in unit 5 of the Edexcel International A-level Biology specification. The previous lesson described the control of heart rate so this lesson has been written to tie in with this and to use this knowledge to further the students understanding of the control of ventilation rate. The lesson begins with a focus on the muscles involved in ventilation, specifically the diaphragm and external intercostal muscles, so that students can understand how their contraction results in an increase in the volume of the thoracic cavity. Boyle’s law is briefly introduced to allow students to recognise the relationship between volume and pressure so that the movement of air with the pressure gradient can be described. Time is then taken to consider the importance of inhalation and an exam-style question challenges the students to explain that a constant supply of oxygen to the alveoli is needed to maintain a steep concentration gradient with the surrounding capillaries. The students are then tasked with writing a description of exhalation at rest using the description of inhalation as their guide. The rest of the lesson focuses on the mechanisms involved in increasing the rate and depth of breathing during exercise. Students will use their knowledge of the control of heart rate to recall that chemoreceptors detect changes in oxygen and carbon dioxide and blood pH and that the medulla oblongata processes the sensory information that it receives before coordinating a response. The final task challenges them to use the information provided in this lesson and the previous one to order 10 detailed descriptions so they can form a complete passage about this control system

This lesson describes the processes that take place during interphase, mitosis and cytokinesis and outlines how checkpoints regulate the cell cycle. The PowerPoint and accompanying resources have been designed to cover points 2.1.6 (a & b) of the OCR A-level Biology specification and prepares the students for the upcoming lessons on the main stages of mitosis and its significance in life cycles The students were introduced to the cell cycle at GCSE so this lesson has been planned to build on that knowledge and to emphasise that the M phase which includes mitosis (nuclear division) only occupies a small part of the cycle. The students will learn that interphase is the main stage and that this is split into three phases, G1, S and G2. A range of tasks which include exam-style questions, guided discussion points and quick quiz competitions are used to introduce key terms and values and to describe the main processes that occur in a very specific order. There is also a focus on the checkpoints, such as the restriction point that occurs before the S phase to ensure that the cell is ready for DNA replication. Extra time is taken to ensure that key terminology is included and understood, such as sister chromatid and centromere, and this focus helps to show how it is possible for genetically identical daughter cells to be formed at the end of the cycle. Important details of mitosis are introduced so students are ready for the next lesson, before the differences in cytokinesis in animal and plant cells are described.