This fully-resourced lesson has been designed to cover the specification point 3.21B (understanding the term co-dominance) as detailed in topic 3 (Reproduction and inheritance) of the Pearson Edexcel IGCSE Biology specification. The lesson uses the inheritance of the ABO blood group system to demonstrate co-dominance. A potentially difficult topic, time has been taken to include guidance sections where students are walked through the interpretation of the different genotypes to find out the phenotypes as well as supporting them through the construction of genetic diagrams and working out the blood groups from pedigree trees. There is a real focus on genetic terminology such as allele, locus, genotype and phenotype so that the understanding is deep and students can use this if they choose to further their studies at A-level. This lesson has been designed for GCSE-aged students studying the Pearson Edexcel IGCSE Biology course but is also suitable for older students who are learning about codominance (and multiple alleles) at A-level

This resource has been designed to cover the higher tier content of specification point 7.8 as detailed in the Edexcel GCSE Biology & Combined Science specifications. The lesson takes the format of a day at a fertility clinic and students will see how three couples, who are at different stages of their currently unsuccessful journey to getting pregnant, are advised and the treatments that could be on offer to them. Discussion points are included throughout the lesson to encourage the students to talk about the Biology and to allow any misconceptions to be addressed if and when they arise. In addition, previous knowledge checks are regular so that the links between this topic and earlier ones such as the hormones in the menstrual cycle and contraception can be made. Students will be introduced to the abbreviation ART before learning how clomifene is used to treat infertility in women do not ovulate. Time is taken to explore alternative fertility drugs and students are challenged to explain why FSH and LH would be the reproductive hormones contained in these substances. The main focus of the lesson is IVF treatment and the main task culminates with students gaining a number of key points in the for and against argument before being challenged to continue this as a set homework in the form of an evaluation. Quiz competitions are used to introduce key terms in a fun and memorable way and the final task is a mathematical skills check where students will be able to compare the high number of multiple births that are associated with this treatment as compared to the number from natural births. This lesson has been designed for students studying the Edexcel GCSE Biology or Combined Science course but is also suitable for older students who are looking at this topic

This resource, which consists of an engaging and detailed PowerPoint and a differentiated worksheet, has been designed to cover the content in the supplement section of topic 14.4 in the CIE IGCSE Biology specification, specifically the control of blood glucose concentration and the symptoms and treatment of diabetes type I. A wide range of activities are found across the lesson which will engage and motivate the students whilst the important content is covered and understanding and previous knowledge checks are included at regular points so students can assess their progress. The following content is covered across this resource: The release of insulin by the pancreas when high glucose levels are detected The role of the liver and muscle cells in the conversion of glucose to glycogen Negative feedback in this homeostatic control mechanism Diagnosis and treatment of type I diabetes Type I diabetes as an autoimmune disease (link to topic 10) The release of glucagon and the role of the liver cells when blood glucose concentration is low As shown above, links are made to other topics where possible so students can recognise the importance of making connections between related subjects. This lesson has been designed for students studying on the CIE IGCSE Biology course but is suitable for older students who are looking at this topic at A-level and need to recall the key details

The engaging PowerPoint and accompanying differentiated worksheets which come as part of this lesson resource have been designed to cover the SUPPLEMENT section of topic 13.1 of the CIE IGCSE Biology specification which states that students should be able to describe the structure and function of the kidneys. Students will initially be introduced to the gross anatomy of the kidneys with the cortex and medulla and the associated ureter before moving on to the fine anatomy of the tubules and focusing on the key functions like ultrafiltration and selective reabsorption. Lots of discussion points and student discovery have been written into the lesson to encourage students to think about why a certain process takes place before attempting to explain it using the Biology. In addition, there are lots of understanding checks and prior knowledge checks so that students are challenged on their knowledge of previously learned topics such as active transport and the components of blood. The final task of the lesson challenges the students to use their knowledge of the formation of urea from earlier in topic 13 and combine it with what they have learnt in this lesson to arrange statements about the journey of this molecule into the right order This lesson has been designed for students who are studying the CIE IGCSE Biology course but is suitable for older students who are studying the kidney at A-level and want to recall some of the key details of the structure and function of this organ

This lesson has been designed to cover the content set out in specification point 2.5 (g) of the WJEC GCSE Biology specification which states that students should understand that hormones are chemical messengers which control many body functions. A wide range of activities have been written into the lesson with the aim of engaging and motivating the students whilst ensuring that the content is covered in detail. These activities include a number of quiz competitions which will challenge the students to identify an endocrine organ when presented with three organs as well as introducing them to the names of some of the hormones released by the pituitary gland. The following content is covered in this lesson: The location of the pituitary, adrenal and thyroid glands in the human body The location of the pancreas, ovaries and testes in the human body The hormones which are secreted by the endocrine glands The effects of the hormones on their target organs This lesson has been written for GCSE-aged students who are studying on the WJEC Biology course but it is suitable for younger students who are looking at this as one of the different organ systems

This engaging REVISION lesson has been designed to cover the content of topic 3 (Enzymes) of the CIE International A-level Biology specification. A wide range of activities have been written into the lesson to engage the students whilst they assess their understanding of the topic content. All of the exam questions contain detailed answers which students can use to identify missed marks and quiz competitions are used, like FROM NUMBERS 2 LETTERS (shown in the cover image) to recall key concepts and check on the finer details. The lesson has been planned to cover as much of the specification content as possible but the following sub-topics have received particular attention: Enzymes as globular proteins that act as biological catalysts Formation of the enzyme-substrate complex The lock and key theory and induced-fit hypothesis Competitive and non-competitive inhibitors The Michaelis-Menten constant The effect of changes in pH and temperature on the tertiary structure of the enzymes The immobilisation of enzymes using alginate Time has been taken in the design to ensure that links to other topics are made. For example, when checking the knowledge of the denaturation of enzymes due to pH and temperature, the bonds found in the tertiary structure are recalled and considered in depth.

This fully-resourced lesson explores the inheritance of genetic characteristics that involve multiple alleles and codominant alleles. The engaging and detailed PowerPoint and differentiated worksheets have been designed to cover the part of point 16.2 (b) of the CIE International A-level Biology specification which states that students should be able to use genetic diagrams to solve problems which involve codominance and multiple alleles. The main part of the lesson uses the inheritance of the ABO blood groups to demonstrate how the three alleles that are found at the locus on chromosome 9 and the codominance of the A and B alleles affects the phenotypes. Students are guided through the construction of the different genotypes and how to interpret the resulting phenotype. They are challenged to use a partially completed pedigree tree to determine the blood group for some of the family members and to explain how they came to their answer. To further challenge their ability to apply their knowledge, a series of questions about multiple alleles and codominance in animals that are not humans are used. All of the questions are followed by clear, visual mark schemes to allow the students to assess their progress and address any misconceptions

This fully-resourced lesson looks at the contribution of environmental and genetic factors to phenotypic variation. The engaging PowerPoint and accompanying worksheets have been designed to cover point 6.1.2 (a) of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply an understanding of how mutations and meiosis and the lack of availability of ions can cause variation within a species. Students are challenged at the start of the lesson to recognise the terms phenotype and species from their definitions in order to begin a discussion on the causes of the phenotypic variation within a species. Moving forwards, students will recall that mutations are the primary source of genetic variation and time is taken to look at the effect of gene and chromosome mutations. Gene mutations were covered earlier in module 6 so these tasks act as a prior knowledge check as students have to recognise the different types of gene mutations and explain their effects on the primary structure with reference to the genetic code. These prior knowledge checks are found throughout the lesson and challenge the knowledge of other topics that include photosynthesis and meiosis. The karyotype of an individual who has Down syndrome is used to introduce chromosome mutations and students will be introduced to the different types, with a focus on non-disjunction. The key events of meiosis that produce variation (crossing over and independent assortment) are explored and students will be given a mathematical formula to use to calculate the number of chromosome combinations in gametes and in the resulting zygote. The final part of the lesson looks at chlorosis and how an environmental factor can prevent the express of a gene. If you would like a lesson that goes into chromosome mutations in even greater detail, please search for the uploaded lesson on that topic which complements this lesson

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

This fully-resourced lesson 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.

This fully-resourced lesson has been designed to cover point 8.4 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification that states that students should know the structures and function of synapses in nerve impulse transmission. The majority of the lesson uses the cholinergic synapse as the example but other neurotransmitters are considered to provide the students with a wider view of this topic and to make links to specification point 8.15 The lesson begins by using a version of the WALL (as shown in the cover image) which asks the students to group 12 words into three groups of 4. Not only will this challenge their prior knowledge from topics earlier in this module but it will also lead to the discovery of four of the structures that are found in a synapse. Moving forwards, students are introduced to aectylcholine as the neurotransmitter involved at cholinergic synapses and they will start to add labels to the structures found in the pre-synaptic bulb. Time is taken to focus on certain structures such as the voltage gated channels as these types of channel were met previously when looking at the depolarisation of a neurone. There is plenty of challenge and discovery as students are pushed to explain why organelles like mitochondria would be found in large numbers in the bulb. With this process being a cascade of events, a bullet point format is used to ensure that the key content is taken in by the students and again key points like exocytosis and the action of acetylcholinesterase are discussed further. The final part of the lesson challenges the application aspect of the specification as students are introduced to unfamiliar situations in terms of synapses with new drugs like MDMA and are asked to work out and explain how these affect the nervous transmission. Understanding checks and prior knowledge checks are included throughout the lesson so that students can not only assess their progress against the current topic but also see whether they can make links to earlier topics.

This fully-resourced lesson looks at how heart rate is controlled by the cardiovascular control centre in the medulla oblongata. The engaging and detailed PowerPoint and accompanying resources have been designed to cover the first part of point 7.9 (ii) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification but also ties in well with previously covered topics and provides a good introduction to control systems which are covered later in topic 7 and 8. 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

This clear and concise lesson explores the importance of coenzymes in cellular respiration as detailed in point 5.2.2 (f) of the OCR A-level Biology A specification. Students encountered coenzymes in module 2.1.4 as well as looking at the roles of NAD, CoA and FAD whilst learning about glycolysis, the link reaction and Krebs cycle earlier in this module. Therefore this lesson was designed to check on their understanding of the importance of these roles and goes on to explain how the transport of the protons and electrons to the mitochondrial cristae is key for the production of ATP. This lesson has been written to tie in with the other uploaded lessons in module 5.2.2 which include the mitochondria, glycolysis, the link reaction and the Krebs cycle

This detailed lesson looks at each of the stages of aerobic respiration and explains how this reaction is a multi-stepped process where each step is controlled by an enzyme. The engaging PowerPoint and accompanying resource have been designed to cover points 7.3 (i) and (ii) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification. 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 atmospheric oxygen being reunited with hydrogen.

This engaging lesson looks at the role of haemoglobin in carrying oxygen and carbon dioxide. The PowerPoint has been designed to cover point 8.1 (f) of the CIE International A-level Biology specification and includes references to the role of carbonic anhydrase and the formation of haemoglobinic acid and carbaminohaemoglobin. The lesson begins with a version of the quiz show Pointless to introduce haemotology as the study of the blood conditions. Students are told that haemoglobin has a quaternary structure and are challenged to use their prior knowledge of biological molecules to determine what this means for the protein. They will learn that each of the 4 polypeptide chains contains a haem group with an iron ion attached and that it is this group which has a high affinity for oxygen. Time is taken to discuss how this protein must be able to load (and unload) oxygen as well as transport the molecules to the respiring tissues. Students will plot the oxyhaemoglobin dissociation curve and the S-shaped curve is used to encourage discussions about the ease with which haemoglobin loads each molecule. The remainder of the lesson looks at the different ways that carbon dioxide is transported around the body that involve haemoglobin. Time is taken to look at the dissociation of carbonic acid into hydrogen ions so that students can understand how this will affect the affinity of haemoglobin for oxygen in an upcoming lesson on the Bohr effect.

This engaging and fully-resourced lesson looks at the effects of stabilising, directional and disruptive selection as the three main types of selection. The PowerPoint and accompanying resources have been designed to cover point 17.2 (b) of the CIE International A-level Biology specification which states that students should be able to identify each type of selection by its effect on different phenotypes. The lesson begins with an introduction to the mark, release, recapture method to calculate numbers of rabbits with different coloured fur in a particular habitat. This method is covered later in topic 18 so this section of the lesson is designed purely to generate changes in numbers of the organisms. Sketch graphs are then constructed to show the changes in the population size in this example. A quick quiz competition is used to engage the students whilst introducing the names of the three main types of selection before a class discussion point encourages the students to recognise which specific type of selection is represented by the rabbits. Key terminology including intermediate and extreme phenotypes and selection pressure are used to emphasise their importance during explanations. A change in the environment of the habitat and a change in the numbers of the rabbits introduces directional selection before students will be given time to discuss and to predict the shape of the sketch graph for disruptive selection. Students are challenged to apply their knowledge in the final task of the lesson by choosing the correct type of selection when presented with details of a population and answer related questions.

This fully-resourced lesson looks at the internal and external structure of the mammalian heart and uses the human heart to represent this anatomy. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 3.1.2 (e) (i) of the OCR A-level Biology A specification As this topic was covered at GCSE, the lesson has been planned to build on this prior knowledge whilst adding the key details which will enable students to provide A-level standard answers. The primary focus is the identification of the different structures of the heart but it also challenges their ability to recognise the important relationship to function. For example, time is taken to ensure that students can explain why the atrial walls are thinner than the ventricular walls and why the right ventricle has a thinner wall than the left ventricle. Opportunities are taken throughout the lesson to link this topic to the others found in topic 3.1.2 including those which have already been covered like circulatory systems as well as those which are upcoming such as the initiation of heart action. There is also an application question where students have to explain why a hole in the ventricular septum would need to be repaired if it doesn’t naturally close over time.

This detailed and fully-resourced lesson describes and explains the pressure changes in the heart and arteries and the role of the valves movements in the cardiac cycle. The PowerPoint and accompanying resources have been designed to cover point 3.1.2 (f) of the OCR A-level Biology A specification and also covers the use of the equation stroke volume x heart rate to calculate cardiac output The start of the lesson introduces the cardiac cycle as well as the key term systole, so that students can immediately recognise that the three stages of the cycle are atrial and ventricular systole followed by diastole. Students are challenged on their prior knowledge of the structure of the heart as they have to name and state the function of an atrioventricular and semi-lunar valve from an internal diagram. This leads into the key point that pressure changes in the chambers and the major arteries results in the opening and closing of these sets of valves. Students are given a description of the pressure change that results in the opening of the AV valves and shown where this would be found on the graph detailing the pressure changes of the cardiac cycle. They then have to use this as a guide to write descriptions for the closing of the AV valve and the opening and closing of the semi-lunar valves and to locate these on the graph. By providing the students with this graph, the next part of the lesson can focus on explaining how these changes come about. Students have to use their current and prior knowledge of the chambers and blood vessels to write 4 descriptions that cover the cardiac cycle. Moving forwards, the students are introduced to the stroke volume and meet normative values for this and for resting heart rate. This will lead into the calculation for cardiac output and a series of questions are used to test their ability to apply this equation as well as to calculate the percentage change which is a commonly assessed mathematical skill. This lesson has been written to tie in with the other uploaded lessons on the topics detailed in module 3.1.2 (Transport in animals)