Adenosine triphosphate is the universal energy currency and this lesson focuses on the role of this molecule in cell. The PowerPoint has been designed to cover point1.2 © of the CIE International A-level Biology specification and also explains how ATP must be hydrolysed to release energy and then re-synthesised during respiration and photosynthesis in the mitochondria and chloroplast respectively. As students were introduced to the structure of DNA and RNA at GCSE, the start of this lesson challenges them on their knowledge of these polynucleotides so that they can recognise that ATP consists of adenine, ribose and three phosphate groups. In order to release the stored energy, ATP must be broken down and students will be given time to discuss which reaction will be involved as well as the products of this reaction. Time is taken to describe how the hydrolysis of ATP can be coupled to energy-requiring reactions within cells and the examples of active transport and skeletal muscle contraction are used as these are covered in greater detail in topics 4 and 15. The final part of the lesson considers how ATP must be re-synthesised and students will learn that this occurs in the mitochondria and chloroplast during aerobic respiration and photosynthesis respectively.

This fully-resourced lesson describes the relationship between the structure and function of the eukaryotic cell structures. The detailed and engaging PowerPoint and accompanying exam-question worksheets (which are all differentiated) have been designed to cover point 1.2 (b) of the CIE International A-level Biology specification As cells are the building blocks of living organisms, it makes sense that they would be heavily involved in all of the 19 topics in the CIE International course and intricate planning has ensured that links to previously covered topics at GCSE are made and details linking to upcoming topics are made throughout the lesson. A wide range of activities, that include exam-style questions, class discussion points and quick quiz competitions, will maintain motivation and engagement whilst covering the finer details of the following structures: nucleus nucleolus ribosomes rough endoplasmic reticulum Golgi apparatus lysosomes smooth endoplasmic reticulum mitochondria cell surface membrane centrioles vacuole chloroplasts cell wall plasmodesmata As mentioned above, all of the worksheets have been differentiated to support students of differing abilities whilst maintaining challenge Due to the detail that is included in this lesson, it is estimated that it will take in excess of 3/4 hours of allocated A-level teaching time to cover the work

This fully-resourced lesson describes the use of vaccinations to protect individuals and populations and the differences between active and passive immunity. The engaging PowerPoint and accompanying resources have been designed to cover the fourth part of point 2.4 of the AQA A-level Biology specification and there is also a description and discussion on the concept of herd immunity. The previous lesson finished with a series of exam questions where students observed differences between the primary and secondary immune responses so the start of this lesson uses an imaginary game of TOP TRUMPS to challenge them on the depth of their understanding. This will act to remind them that a larger concentration of antibodies is produced in a quicker time in the secondary response. 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 the roles of the T and B lymphocytes in the cellular and humoral responses and the development of immunological memory. The detailed PowerPoint and accompanying resources have been designed to cover the third part of point 2.4 of the AQA A-level Biology specification and the structure of antibodies and the roles of plasma cells and memory cells in the primary and secondary immune responses are also included. Antigen presentation was introduced at the end of the previous lesson so the task at the start of this lesson challenges students to recognise the name of this process and then they have to spot the errors in the passage that describes the details of this event. This reminds them that contact between the APC and T lymphocytes is necessary to elicit a response which they will come to recognise as the cellular response. A series of quick quiz rounds reveals key terms in a memorable way and one that is introduced is helper T cells. Time is then taken to describe the importance of cell signalling for an effective response and students will learn how the release of chemicals by these cells activates other aspects of the response. The role of the killer T cells is also described before an exam-style question is used to check on their understanding at this point of the lesson. This leads into the section of the lesson that deals with the humoral response and students will understand how this involves the antibodies that are produced by the plasma cells that are the result of clonal selection and expansion. The remainder of the lesson focuses on the structure of the antibodies and then explains how the retention of memory B cells after the primary response enables a quicker and more effective secondary response to occur if necessary. Finally, students are challenged with a series of application questions where they have to apply their knowledge to potentially unfamiliar situations.

This lesson describes the sequence of events that occur during the phagocytosis of pathogens and the subsequent destruction by lysozymes. The engaging and detailed PowerPoint and accompanying resources have been primarily designed to cover the second part of point 2.4 of the AQA A-level Biology specification but includes an introduction to antigen-presentation so that the students are prepared for upcoming lessons on the cellular 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 a brief introduction to lymphocytes so that initial links between phagocytosis and the specific immune responses are made.

This detailed and engaging lesson describes the movement of water molecules by osmosis and this is explained in terms of water potential. Both the PowerPoint and accompanying resources have been designed to cover the third part of specification point 2.3 as detailed in the AQA A-level Biology specification and they also describe the impact of solutions of different water potentials on suspended animal and plant cells. It’s likely that students will have used the term concentration in their osmosis definitions at GCSE, so the aim of the starter task is to introduce water potential to allow students to begin to recognise osmosis as the movement of water molecules from a high water potential to a lower potential, with the water potential gradient. Time is taken to describe the finer details of water potential to enable students to understand that 0 is the highest value (pure water) and that this becomes negative once solutes are dissolved. Exam-style questions are used throughout the lesson to check on current understanding as well as prior knowledge checks which make links to previously covered topics such as the lipid bilayer of the cell membrane. The remainder of the lesson focuses on the movement of water when animal and plant cells are suspended in hypotonic, hypertonic or isotonic solutions and the final appearance of these cells is described, including any issues this may cause. This lesson has been specifically written to tie in with the previous two lessons in topic 2.3 that cover the cell membrane and diffusion as well as an upcoming lesson on active transport and co-transport.

This lesson describes the movement across cell membranes by simple and facilitated diffusion and describes how the rate is increased. The PowerPoint and accompanying resources have been designed to cover the second part of specification point 2.3 of the AQA A-level Biology course and the limitations imposed by the phospholipid bilayer and the role of channel and carrier proteins are described in detail. The structure and properties of cell membranes was covered in the previous lesson so this one has been written to include continual references to the content of these lessons. This enables links to be made between the movement across a cell membrane with the concentration gradient, the parts of the membrane that are involved and any features that may increase the rate at which the molecules move. A series of questions about the alveoli are used to demonstrate how a large surface area, a short diffusion distance and the maintenance of a steep concentration gradient will increase the rate of simple diffusion. One of two quick quiz rounds is then used to introduce temperature and size of molecule as two further factors that can affect simple diffusion. The remainder of the lesson focuses on facilitated diffusion and describes how transmembrane proteins are needed to move small, polar or large molecules from a high concentration to a lower concentration across a partially permeable membrane.

This detailed lesson describes the structure and properties of the cell membrane, focusing on the phospholipid bilayer and membrane proteins. Fully resourced, the PowerPoint and accompanying worksheets have been designed to cover the first part of point 2.3 of the AQA A-level Biology specification and clear links are made to Singer and Nicholson’s fluid mosaic model The fluid mosaic model is introduced at the start of the lesson so that it can be referenced at appropriate points throughout the lesson. Students were introduced to phospholipids in topic 1 and so an initial task challenges them to spot the errors in a passage describing the structure and properties of this molecule. This reminds them of the bilayer arrangement, with the hydrophilic phosphate heads protruding outwards into the aqueous solutions on the inside and the outside of the cell. In a link to some upcoming lessons on the transport mechanisms, the students will learn that only small, non-polar molecules can move by simple diffusion and that this is through the tails of the bilayer. This introduces the need for transmembrane proteins to allow large or polar molecules to move into the cell by facilitated diffusion and active transport. Proteins that act as receptors as also introduced and an opportunity is taken to make a link to an upcoming topic so that students can understand how hormones or drugs will bind to target cells in this way. Moving forwards, the structure of cholesterol is covered and students will learn that this hydrophobic molecule sits in the middle of the tails and therefore acts to regulate membrane fluidity. The final part of the lesson challenges the students to apply their newly-acquired knowledge to a series of questions where they have to explain why proteins may have moved when two cells are used and to suggest why there is a larger proportion of these proteins in the inner mitochondrial membrane than the outer membrane.

This fully-resourced lesson describes the behaviour of chromosomes during interphase, mitosis and cytokinesis in the cell cycle. The detailed PowerPoint and accompanying resources have been designed to cover the first half of point 2.2 as detailed in the AQA A-level Biology specification whereas uncontrolled cell division and cancer and binary fission are covered in upcoming lessons. Depending upon the exam board taken at GCSE, the knowledge and understanding of mitosis and the cell cycle will differ considerably between students and there may be a number of misconceptions. This was considered at all points during the planning of the lesson and to address existing errors, key points are emphasised throughout. The cell cycle is introduced at the start of the lesson and the quantity of DNA inside the parent cell is described as diploid and as 2n. 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. Moving forwards, the first real focus is interphase and 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. The main part of the lesson focuses on prophase, metaphase, anaphase and telophase and describes how the chromosomes behave in these stages. Centrioles were not covered in the topic 2.1 lessons on cell structures so a quick task will introduce them to these organelles who are responsible for the production of the spindle apparatus, 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 engaging lesson explains why viruses are described as acellular and non-living and describes the structures of virus particles. The PowerPoint and accompanying resource have been designed to cover the second part of specification point 2.1.2 of the AQA A-level Biology specification and also includes details of HIV so that students are prepared for this lesson later in topic 2. Details of the COVID-19 epidemic are included in the lesson to increase relevance and to help students to understand this biological topic in greater depth. They will understand that the lack of cell structures results in an acellular classification and the fact that it is unable to reproduce without a host is one of the additional reasons that renders it as non-living. The main focus of the lesson is the nucleic acid, the capsid and the attachment proteins that are present in these microorganisms and time is taken to explain how these structures are involved in the infection of a host cell. The lipid membrane is also introduced and links are made to the previous lessons on eukaryotic cells. The final section uses a version of BBC 1’s POINTLESS to introduce a number of viral diseases in animals and the use of a glycoprotein by HIV to attach to helper T cells is briefly introduced.

This detailed lesson describes how the structure of a prokaryotic cell differs from the structure of an eukaryotic cell. The engaging PowerPoint and accompanying resources have been designed to cover the first part of point 2.1.2 of the AQA A-level Biology specification and describes how the size and cell structures differ and also covers the additional features that are found in some prokaryotic cells. A clear understanding of terminology is important for A-level Biology so this lesson begins with a challenge, where the students have to add an additional prefix to their prefix and suffix table which they believe will translate 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 the eukaryotic cells of complex multicellular organisms become specialised for specific functions. The detailed and engaging PowerPoint and accompanying resources have been designed to cover the 3rd part of point 2.1.1 of the AQA A-level Biology specification and also describes how these specialised cells are organised into tissues, organs and organ systems. The start of the lesson focuses on the difference in the SA/V ratio of an amoeba and a human in order to begin to explain why the process of differentiation is critical for multicellular organisms. Students will discover that a zygote is a stem cell which can express all of the genes in its genome and divide by mitosis. Time is then taken to introduce gene expression as this will need to be understood in the later topics of the course. Moving forwards, the lesson uses the process of haematopoiesis from haematopoietic stem cells to demonstrate how the red blood cell and neutrophil differ significantly in structure despite arising from the same cell along the same cell lineage. A series of exam-style questions will not only challenge their knowledge of structure but also their ability to apply this knowledge to unfamiliar situations. These differences in cell structure is further exemplified by the epithelial cells of the respiratory tract and students will understand why the shape and arrangement of these cells differ in the trachea and alveoli in line with function. The link between specialised cells and tissues is made at this point of the lesson with these examples of epithelium and students will also see how tissues are grouped into organs and then into organ systems. The remainder of the lesson focuses on specialised plant cells and the differing shapes and features of the palisade and spongy mesophyll cells and the guard cells are covered at length and in detail. Step by step guides will support the students so that they can recognise the importance of the structures and links are made to upcoming topics such as diffusion, active transport and osmosis so that students are prepared for these when covered in the future. This lesson has been written to continually tie in with the previous two lessons in this specification point which are uploaded under the titles of the structure of eukaryotic animal and plant cells.

This lesson describes the relationship between the structure and function of the vacuole, chloroplast and cell wall, as found in plant cells. Additional structures, such as the nucleus and mitochondria, were covered in the previous lesson on the structure of eukaryotic animal cells and the detailed content of these two lessons has been designed in parallel to cover the main content of point 2.1.1 of the AQA A-level Biology specification. The lesson begins with a task called REVERSE GUESS WHO which will challenge the students to recognise a cell structure from a description of its function. This will remind students that plant cells are eukaryotic and therefore contain a cell-surface membrane, a nucleus (+ nucleolus), a mitochondria, a Golgi apparatus, ribosomes and rough and smooth endoplasmic reticulum like the animal cells. Moving forwards, the rest of the lesson focuses on the relationship between the structure and function of the vacuole, chloroplast and cellulose cell wall. When considering the vacuole, key structures such as the tonoplast are described as well as critical functions including the maintenance of turgor pressure. A detailed knowledge of the structure of the chloroplast at this early stage of their A-level studies will increase the likelihood of a clear understanding of photosynthesis when covered in topic 5. For this reason, time is taken to consider the light-dependent and light-independent reactions and to explain how these stages are linked. The final part of the lesson challenges the students on their knowledge of cellulose as a polysaccharide as previously covered in topic 1. In addition to the focus on plant cells, the presence of chloroplasts and a cell wall in algae and the latter in fungi is also described. The previous lesson which contains the content that ties in closely with this one has been uploaded under the title “Structure of eukaryotic (animal) cells”

This fully-resourced lesson describes the relationship between the structure and function of the structures that are found in eukaryotic cells. The engaging and detailed PowerPoint and accompanying exam-question worksheets (which are all differentiated) have been designed to cover the first part of specification point 2.1.1 of the AQA A-level Biology specification and focuses on those structures found in animal cells. The additional structures, which are found in plant cells, are described in the next lesson uploaded under the title “Structure of eukaryotic (plant) cells”. As cells are the building blocks of living organisms, it makes sense that they would be heavily involved in all of the 8 topics in the AQA course and intricate planning has ensured that these links to previously covered topics as well as upcoming ones are made throughout the lesson. A wide range of activities, that include exam-style questions, class discussion points and quick quiz competitions, will maintain motivation and engagement whilst covering the finer details of the following structures: nucleus nucleolus ribosomes rough endoplasmic reticulum Golgi apparatus lysosomes smooth endoplasmic reticulum mitochondria cell surface membrane As mentioned above, all of the worksheets have been differentiated to support students of differing abilities whilst maintaining challenge Due to the detail that is included in this lesson, it is estimated that it will take in excess of 3 hours of allocated A-level teaching time to cover the work

This fully-resourced lesson uses the lac operon as an example to describe how gene expression is regulated and controls cell processes and structures. The detailed PowerPoint and accompanying resources have been designed to cover the details of specification point 3.12 of the Pearson Edexcel A-level Biology A course. This is one of the more difficult concepts in this A-level course and therefore key points are reiterated throughout this lesson to increase the likelihood of student understanding and to support them when trying to make links to actual biological examples in living organisms. There is a clear connection to transcription and translation as covered in topic 2, so the lesson begins by reminding students that in addition to the structural gene in a transcription unit, there is the promotor region where RNA polymerase binds. Students are introduced to the idea of transcription factors and will understand how these molecules can activate or repress transcription by enabling or preventing the binding of the enzyme. At this point, students are challenged on their current understanding with a series of questions about DELLA proteins so they can see how these molecules prevent the binding of RNA polymerase. The main section of the lesson focuses on the lac operon. Students will be able to visualise the different structures that are found in this unit of DNA and time is taken to go through the individual functions. A step by step guide is used to walk students through the sequence of events that occur when lactose is absent and when it is present before they are challenged to apply their understanding to an exam question. The final section of the lesson looks at one further example with oestrogen and the ER receptor.

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.