This fully-resourced lesson describes the role of mitosis and the cell cycle in producing identical cells for growth and asexual reproduction. The detailed PowerPoint and accompanying differentiated resources have been designed to cover point 3.10 of the Pearson Edexcel A-level Biology A specification In the previous lesson covering meiosis (3.9), students were introduced to the different phases and structures involved in the cycle so this lesson builds on that by providing greater detail of the key events in each phase. Beginning with a focus on interphase, the importance of DNA replication is explained so that students can initially recognise that there are pairs of identical sister chromatids and then can understand how they are separated later in the cycle. A quiz competition has been written into the lesson and this runs throughout, challenging the students to identify the quantity of DNA in the cell (in terms of n) at different points of the cycle. The main part of the lesson focuses on prophase, metaphase, anaphase and telophase and describes how the chromosomes behave in these stages. Students will understand how the cytoplasmic division that occurs in cytokinesis results in the production of genetically identical daughter cells. This leads into a series of understanding and application questions where students have to identify the various roles of mitosis in living organisms as well as tackling a Maths in a Biology context question. The lesson concludes with a final round of MITOSIS SNAP where they only shout out this word when a match is seen between the name of a phase, an event and a picture.

This fully-resourced lesson describes how phenotype is the result of an interaction between genotype and the environment and can be affected by multiple alleles at many gene loci. The engaging PowerPoint and accompanying resources have been primarily designed to cover points 3.14 (i) & 3.15 of the Pearson Edexcel A-level Biology A specification but also includes activities to challenge the students on previous concepts in topics 3 and 2. The students begin the lesson by having to identify phenotype and species from their respective definitions so that a discussion can be encouraged where they will recognise that phenotypic variation within a species is due to both genetic and environmental factors. The main part of the the lesson focuses on these genetic factors, and describes how mutation and the events of meiosis contribute to this variation. A range of activities, which include exam-style questions and quick quiz rounds, are used to challenge the students on their knowledge and understanding of substitution mutations, deletions, insertions, the genetic code, crossing over and independent assortment. Moving forwards, the concept of multiple alleles is introduced and students will learn how the presence of more than 2 alleles at a locus increases the number of phenotypic variants. Another quick quiz round is used to introduce polygenic inheritance and the link is made between this inheritance of genes at a number of loci as an example of continuous variation. The final part of the lesson describes a few examples where environmental factors affect phenotype, such as chlorosis in plants. As this is the final lesson in topic 3, the numerous activities can be used for revision purposes and to show the links between different biological topics.

This fully-resourced lesson explains how individuals develop immunity and includes a focus on the different types (active, passive, natural, artificial). The engaging PowerPoint and accompanying resources have been designed to cover point 6.12 of the Pearson Edexcel A-level Biology A specification and there is also a description and discussion of herd immunity to increase the relevance to the current epidemic with COVID-19. The lesson begins with a series of exam-style questions which challenge the students to demonstrate and apply their understanding of the immune response as covered in the previous lessons on topics 6.8 & 6.9. In answering and assessing their answers to these questions, the students will recognise the differences between the primary and secondary immune responses and are then encouraged to discuss how the production of a larger concentration of antibodies in a quicker time is achieved. The importance of antibodies and the production of memory cells for the development of immunity is emphasised and this will be continually referenced as the lesson progresses. The students will learn that this response of the body to a pathogen that has entered the body through natural processes is natural active immunity. Moving forwards, time is taken to look at vaccinations as an example of artificial active immunity. Another series of questions focusing on the MMR vaccine will challenge the students to explain how the deliberate exposure to antigenic material activates the immune response and leads to the retention of memory cells. A quick quiz competition is used to introduce the variety of forms that the antigenic material can take along with examples of diseases that are vaccinated against using these methods. The eradication of smallpox is used to describe the concept of herd immunity and the students are given time to consider the scientific questions and concerns that arise when the use of this pathway is a possible option for a government. The remainder of the lesson looks at the different forms of passive immunity and describes the drawbacks in terms of the need for a full response if a pathogen is reencoutered.

This fully-resourced lesson describes how it’s possible for 1 gene to give rise to multiple proteins as a result of post-transcriptional changes to mRNA. The detailed PowerPoint and accompanying resources have been primarily designed to cover point 6.10 of the Pearson Edexcel A-level Biology A specification but also checks on the students knowledge and understanding of the lac operon as covered in topic 3. 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. At this point, the students will complete a task that acts as a prior knowledge check where they have to identify the 6 errors in the descriptive passage about the lac operon and its role in the regulation of gene expression in prokaryotes. 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 how the polymerase chain reaction (PCR) is used to amplify DNA. The concise PowerPoint has been primarily designed to cover the detail of specification point 6.4 of the Pearson Edexcel A-level Biology A specification but also makes continual links to the previous lesson on DNA profiling where the PCR is important as well as DNA structure. A quick quiz competition is used to introduce the PCR abbreviation before students are encouraged to discuss with the aim of identifying the enzyme involved and to recall the action of this enzyme as covered in DNA replication in topic 2. Students will learn that this reaction involves cyclical heating and cooling to a range of temperatures so another quiz is used to introduce these values. The main part of the lesson describes the main steps in the PCR and the reasons for each temperature is discussed and explained. Links are constantly made to related topics such as DNA structure are students are challenged on their understanding through exam-style questions. Time is taken to examine the key points in detail, such as the fact that the DNA polymerase used is taken from an extremophile so that it is not denatured at the high temperature.

This fully-resourced lesson describes the roles of antigens, antibodies, B cells and T cells in the body’s immune response. The PowerPoint and accompanying worksheets have been designed to cover specification points 6.8 & 6.9 as detailed in the Pearson Edexcel A-level Biology A specification and includes descriptions of the involvement of plasma (effector) cells and macrophages as antigen-presenting cells. In the previous lesson on the non-specific responses, the students were introduced to macrophages and dendritic cells as antigen-presenting cells and the start of this lesson challenges their recall and understanding of this process. Time is taken to discuss how the contact between these cells and lymphocytes is critical for the initiation of the body’s (specific) immune response. Moving forwards, a quick quiz competition is used to introduce the names of the different T cells that result from differentiation. Their specific roles are described including an emphasis on the importance of the release of cytokines in cell signalling to activate other immune system cells. T memory cells are also introduced so that students can understand their role in immunological memory and active immunity as described in an upcoming lesson covering point 6.12. The next part of the lesson focuses on the B cells and describes how clonal selection and clonal expansion results in the formation of memory B cells and effector cells. A series of understanding and application questions are then used to introduce the structure of antibodies and to explain how the complementary shape of the variable region allows the antigen-antibody complex to be formed. The lesson concludes by emphasising that the pathogen will be overcome as a result of the combination of the actions of phagocytes, T killer cells and the antibodies released by the effector cells.

This fully-resourced lesson describes the non-specific responses of the body to infection and includes details of phagocytosis, inflammation and interferon release. The engaging and detailed PowerPoint and accompanying resources have been primarily designed to cover the content of point 6.7 of the Pearson Edexcel A-level Biology A specification but topics including antigen-presentation are also introduced to prepare students for upcoming lessons on the immune response (6.8 & 6.9). 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 importance of cell signalling for an effective immune response is discussed and the rest of the lesson focuses on the release of two chemicals - interferons and histamine. During the interferon section, references are made to a previous lesson on HIV structure and action so students can understand how the release of these signalling proteins helps neighbouring cells to heighten their anti-viral defences. A step by step guide is used to describe the release of histamine in the inflammatory response and the final task challenges students to use this support to form a detailed answer regarding the steps in inflammation.

This fully-resourced lesson describes the key steps in the blood clotting process, including the roles of thromboplastin, thrombin and fibrin. The engaging PowerPoint and accompanying worksheets have been primarily designed to cover the content detailed in point 1.11 of the Edexcel A-level International specification but time has been taken to look at haemophilia as a sex-linked disease so that students are prepared for when this is covered in greater detail in topic 3. The lesson begins with the introduction of clotting factors as integral parts of the blood clotting process and explains that factor III, thromboplastin, needs to recalled as well as the events that immediately precede and follows its release. Students will learn how damage to the lining and the exposure of collagen triggers the release of this factor and how a cascade of events then results. Quick quiz rounds and tasks are used to introduce the names of the other substances involved which are prothrombin, thrombin, fibrinogen and fibrin. In a link to the upcoming topic of proteins, students will understand how the insolubility of fibrin enables this mesh of fibres to trap platelets and red blood cells and to form the permanent clot. In the previous lessons, students described the events in atherosclerosis and a link is made to the role of blood clotting in CVD. The final part of the lesson introduces haemophilia as a sex-linked disease and students are challenged to apply their knowledge to an unfamiliar situation as they have to write genotypes and determine phenotypes before explaining why men are more likely to suffer from this disease than women.

Water is very important for living organisms because of its numerous properties and this lesson focuses on its role as a solvent in transport. The engaging and detailed PowerPoint and accompanying worksheet have been designed to cover point 1.1 of the Edexcel International A-level Biology specification and also explains the importance of the dipole nature for this role in transport. A mathematical theme runs throughout the lesson as students have to match the numbers calculated in the starter task to water statistics, such as the percentage of the volume of blood plasma that is water. This has been included to try to increase the relevance of each property so that it can be described in a biological context. Time is taken at the beginning of the lesson to describe the structure of water in terms of the covalent bonds between the oxygen and hydrogen atoms as well as the hydrogen bonds which form between molecules because of its polarity. Students will understand how water is a solvent which means that it is critical for transport in animals, a topic covered in the next few lessons but also for transport in plants as discussed in topic 4. The high heat capacity and latent heat of vaporisation of water is also discussed and explained through the examples of thermoregulation and the maintenance of a stable environment for aquatic animals. The final part of the lesson focuses on the involvement of water in condensation and hydrolysis reactions, two reactions which must be well understood for topic 1 and 2 and the formation and breakage of polysaccharides, lipids, polypeptides and polynucleotides.

Simple and facilitated diffusion are forms of passive transport and this lesson describes the factors that increase the rate of this movement across membranes. This fully-resourced lesson is the first in a series of two that have been designed to cover specification point 2.4 of the Pearson Edexcel A-level Biology A and the involvement of channel and carrier proteins is also described and discussed. In a number of previous lessons that covered specification points 2.1 and 2.2, students were provided with the details of gas exchange surfaces and the structure and properties of cell membranes. This lesson continually refers back to the content of these lessons so that links can be made between the movement across a cell membrane with the concentration gradient, the parts of the membrane involved and any features that may increase the rate at which the molecules move. A series of questions about the alveoli is used to demonstrate how a large surface area, a short diffusion distance and the maintenance of a steep concentration gradient will increase the rate of simple diffusion. One of two quick quiz rounds is then used to introduce temperature and size of molecule as two further factors that can affect simple diffusion. The remainder of the lesson focuses on facilitated diffusion and describes how transmembrane proteins are needed to move small, polar or large molecules from a high concentration to a lower concentration across a partially permeable membrane. The other lesson included in this series to cover specification point 2.4 describes active transport, endocytosis and exocytosis.

This lesson describes how the relationship between the different properties of water and its roles in living organisms. The engaging PowerPoint has been designed to cover specification point 2.3 (d) of the CIE International A-level Biology course. Hydrolysis reactions have been a recurring theme throughout topic 2, so the start of this lesson challenges the students to recognise the definition when only a single word is shown: water. Students will also recall the meaning of a condensation reaction. Moving forwards, the rest of the lesson focuses on the relationship between the structure and properties of water, beginning with its role as an important solvent. The lesson has been specifically written to make links to future topics and this is exemplified by the transport of water along the xylem in plants which is covered in topic 7. The next section focuses on the high latent heat of vaporisation and heat capacity of water and these properties are put into biological context using thermoregulation and the maintenance of a stable environment for aquatic animals. The lesson finishes with an explanation of the polar nature of water, a particularly important property that needs to be well understood for a number of upcoming topics, such as cell membranes.

This detailed lesson uses haemoglobin and collagen to describe the relationship between the structure and functions of globular and fibrous proteins. The engaging PowerPoint and accompanying worksheet have been primarily designed to cover specification point 2.3 © of the CIE International A-level Biology course but due to the detailed coverage of haemoglobin, this resource could also be used when teaching a lesson on the role of this protein in topic 8. The first part of the lesson looks at the structure of haemoglobin, and describes how the presence of an iron-containing haem group on the outside of the 4 polypeptide chains explains its ability to form oxyhaemoglobin. Moving forwards, the importance of the solubility of this protein is considered and related to the direction that the hydrophobic R groups point. At this point of the lesson, the students are challenged to construct a comparison table which can be filled in as the lesson progresses and as they are given more details of collagen. The section of the lesson concerning collagen begins with the introduction of its function in the artery wall so that students can recognise how fibrous proteins have roles associated with mechanical strength. Time is taken to discuss their solubility as well as the presence of repetitive amino acid sequences. The remainder of the lesson considers four more proteins and the final task challenges the students to use their completed table to write a summary passage comparing globular and fibrous proteins.

This detailed lesson describes the different levels of protein structure and focuses on the bonds that hold these molecules in shape. Both the engaging PowerPoint and accompanying resources have been designed to cover specification point 2.3 (b) of the CIE International A-level Biology course and makes continual links to previous lessons such as amino acids & peptide bonds as well as to upcoming lessons like enzymes and antibodies. The start of the lesson focuses on the formation of a peptide bond during a condensation reaction so that students can understand how a dipeptide is formed and therefore how a polypeptide forms when multiple reactions occur. The main part of the lesson describes the different levels of protein structure. A step by step guide is used to demonstrate how the sequences of bases in a gene acts as a template to form a sequence of codons on a mRNA strand and how this is translated into a particular sequence of amino acids known as the primary structure. The students are then challenged to apply their understanding of this process by using three more gene sequences to work out three primary structures and recognise how different genes lead to different sequences. Moving forwards, students will learn how the order of amino acids in the primary structure determines the shape of the protein molecule, through its secondary, tertiary and quaternary structure and time is taken to consider the details of each of these. There is a particular focus on the different bonds that hold the 3D shape firmly in place and a quick quiz round then introduces the importance of this shape as exemplified by enzymes, antibodies and hormones. Students will see the differences between globular and fibrous protein and again biological examples are used to increase relevance. The lesson concludes with one final quiz round called STRUC by NUMBERS where the students have to use their understanding of the protein structures to calculate a numerical answer.

This lesson describes the structure of an amino acid and the formation and breakage of a peptide bond. The PowerPoint has been designed to cover specification point 2.3 (a) of the CIE International A-level Biology course and provides a clear introduction to the following lesson on the formation of dipeptides and polypeptides. The lesson begins with a prior knowledge check, where the students have to use the 1st letters of 4 answers to uncover a key term. This 4-letter key term is gene and the lesson begins with this word because it is important for students to understand that these sequences of bases on DNA determine the specific sequence of amino acids in a polypeptide. Moving forwards, students are given discussion time to work out that there are 64 different DNA triplets and will learn that these encode for the 20 amino acids that are common to all organisms. The main task of the lesson is an observational one, where students are given time to study the displayed formula of 4 amino acids. They are not allowed to draw anything during this time but will be challenged with 3 multiple choice questions at the end. This task has been designed to allow the students to visualise how the 20 amino acids share common features in an amine and an acid group. A quick quiz round introduces the R group and time is taken to explain how the structure of this side chain is the only structural difference. Students will be introduced to the existence of hydrophobic and hydrophilic R groups so that they are able to apply this knowledge in future lessons where structure and shape is considered. Some time is also given to look at cysteine in greater detail due to the presence of sulfur atoms and once again a link is made to disulfide bridges for upcoming lessons. Another quiz round called LINK TO THE FUTURE will allow the students to recognise the roles performed by amino acids in the later part of the course such as translation and in the formation of dipeptides. The lesson concludes with a task that describes the breakage of the peptide bonds during hydrolysis reactions.

This engaging lesson describes the relationship between the structure and functions of a phopholipid, focusing on the role performed in membranes. The PowerPoint has been designed to cover specification point 2.2 (g) of the CIE International A-level Biology specification and includes constant references to the previous lesson on the structure and function of triglycerides. The role of a phospholipid in a cell membrane provides the backbone to the whole lesson. A quick quiz round called FAMILY AFFAIR challenges the students to use their knowledge of the structure of a triglyceride to identify the shared features in a phospholipid. This then allows the differences to be introduced, such as the presence of a phosphate group in place of the third fatty acid. Moving forwards, the students will learn that the two fatty acid tails are hydrophobic whilst the phosphate head is hydrophilic which leads into a key discussion point where the class has to consider how it is possible for the phospholipids to be arranged when both the inside and outside of a cell is an aqueous solution. The outcome of the discussion is the introduction of the phospholipid bilayer which is critical for the lesson in topic 4 on the fluid mosaic model. The final part of the lesson describes how proteins found floating in the cell membrane allow both facilitated diffusion and active transport to occur and this also helps to begin the preparations for the upcoming lessons.

This fully-resourced lesson describes the relationship between the molecular structure of a triglyceride and its functions in living organisms. The engaging PowerPoint and accompanying worksheets have been designed to cover specification point 2.2 (f) of the CIE International A-level Biology course and links are also made to related future topics such as the importance of the myelin sheath for the conduction of an electrical impulse and the use of lipids as a respiratory substrate. The lesson begins with a focus on the basic structure and roles of lipids, including the elements that are found in this biological molecule and some of the places in living organisms where they are found. Moving forwards, the students are challenged to recall the structure of the carbohydrates from earlier in topic 2 so that the structure of a triglyceride can be introduced. Students will learn that this macromolecule is formed from one glycerol molecule and three fatty acids and have to use their understanding of condensation reactions to draw the final structure. Time is taken to look at the difference in structure and properties of saturated and unsaturated fatty acids and students will be able to identify one from the other when presented with a molecular formula. The final part of the lesson explores how the various properties of a triglyceride mean that it has numerous roles in organisms including that of an energy store and source and as an insulator of heat and electricity.

This detailed and fully-resourced lesson describes the relationship between the structure, properties and functions of glycogen, starch and cellulose. The engaging PowerPoint and accompanying resources have been designed to cover specification point 2.2 (e) of the CIE International A-level Biology course and continual links are also made to the previous lessons in this topic where the monosaccharides and disaccharides were introduced. The lesson begins with the CARBOHYDRATE WALL where students have to use their prior knowledge to collect the 9 carbohydrates on show into 3 groups. This results in glycogen, starch and cellulose being grouped together as polysaccharides and the structure, properties and functions of these large carbohydrates are covered over the course of the lesson. Students will learn how key structural features like the 1 - 4 and 1 - 6 glycosidic bonds and the hydrogen bonds dictate whether the polysaccharide chain is branched or unbranched and also dictate whether the chain spirals or not. Following the description of the structure of glycogen, students are challenged to design an exam question in the form of a comparison table so that it can be completed as the lesson progresses and they learn more about starch and cellulose. This includes a split in the starch section of the table so that the differing structures and properties of amylose and amylopectin can be considered. The importance of the compact structure for storage is discussed as well as the branched chains of amylopectin acting as quick source of energy when it is needed. In the final part of the lesson, time is taken to focus on the hydrogen bonds between rotated glucose molecules on the same chain and between different chains and to explain how the formation of cellulose microfibrils and macrofibrils provides plant cells with the additional strength needed to support the whole plant. Due to the detail included in this lesson, it is estimated that it will take in excess of 2 hours of allocated teaching time to complete