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 the principles of cell fractionation and ultracentrifugation as used to separate cell components. The engaging PowerPoint and accompanying resources are part of the final lesson in a series of 4 lessons which have been planned to cover the details of point 2.1.3 of the AQA A-level biology specification. This lesson begins by informing the students that several of the key terms in this lesson, including the lesson title, end in -ation, and therefore they have to use the clues to work out that the 1st one is cell fractionation. A quiz round like this runs throughout the lesson, introducing homogenisation, filtration and ultracentrifugation in a memorable way. Time is taken to explain each of the processes in detail, and where possible, links are made to previously covered content as well as content that will be met in future lessons. For example, students will learn that the solution must be kept ice-cold and isotonic, and they are challenged to recognise that the low temperature is to reduce the activity of potentially damaging enzymes, before being told that there will be no net movement of water by osmosis because of the isotonic solution. The answers to all understanding and prior knowledge checks are embedded into the PowerPoint to allow students to assess their progress. When explaining the process of ultracentrifugation, the students are given an opportunity to predict which of 6 listed organelles will be found in the 1st pellet because it is the heaviest, right down to the lightest organelle. The lesson finishes with several exam-style questions to check that they’ve understood this separation technique and have a strong knowledge of cells and their organelles. This lesson has been planned to continously link with the other lessons in topic 2.1 (Cell structure).

This lesson explains how uncontrolled cell division can lead to the formation of tumours and considers the differences between benign and malignant. The PowerPoint and accompanying resources have been planned to cover point 5.1 (6) of the CIE A-level biology specification (for assessment in 2025 - 2027), The lesson begins with the introduction of the meaning of the mitotic index as well as its formula and the students are then challenged to apply their understanding of this unfamiliar formula to a series of exam-style questions. This will challenge their mathematical skills along with the recollection of the details of the cell cycle that were met in the earlier lessons in topic 5.1. Moving forwards, the potential meanings of a high mitotic index are explored, including high rates of growth and tissue repair, before students are supported to understand that this could indicate that cell division has become uncontrolled. The key term tumour is revealed during a quick quiz round and then the remaining part of the lesson considers how benign and malignant tumours differ. Understanding checks and prior knowledge checks are found throughout the lesson and the answers are embedded into the PowerPoint to allow the students to assess their progress.

This fully-resourced REVISION lesson has been written to challenge the students on their knowledge of the content of topic 1 (Cell structure) of the CIE International A-level Biology specification. The PowerPoint and accompanying resources will motivate the students whilst they assess their understanding of the content and identify any areas which may require further attention. The wide range of activities have been written to cover as much of the topic as possible but the following specification points have been given particular focus: ATP is produced in mitochondria and chloroplasts and the role of ATP in cells Recognising eukaryotic cell structures and outlining their functions Calculating actual sizes from electron micrographs The structural features of a typical prokaryotic cell The key features of viruses as non-cellular structures Distinguish between resolution and magnification Quiz rounds such as “GUESS WHO of CELL STRUCTURES” and “YOU DO THE MATH” are used to test the students on the finer details of their knowledge of the structure and functions of the organelles and some key numerical facts

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 ultrastructure of a prokaryotic cell including the cell wall, capsule,plasmid, flagellum, pili, ribosomes, mesosomes and circular DNA. The engaging PowerPoint and accompanying resources have been designed to cover the specification point 3.4 that is detailed in the Pearson Edexcel A-level Biology A specification but also makes continual references to eukaryotic cells as covered in 3.1 - 3.3 so that comparisons can be made. A clear understanding of terminology is important for A-level Biology so this lesson begins with a challenge, where the students have to come up with a 3-letter prefix that they believe will translate as before or in front of . This leads into the discovery of the meaning of prokaryote as before nucleus which 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 so that students can recognise that prokaryotic cells do not contain centrioles

This detailed lesson describes the structure and properties of the cell membrane, focusing on the phospholipid bilayer, cholesterol and membrane proteins. The detailed PowerPoint and accompanying resources have been designed to cover the details of point 2.2 (i) of the Edexcel International A-level Biology specification and clear links are made to Singer and Nicholson’s fluid mosaic model which is covered in the following lesson Students met triglycerides in topic 1 and so a quick quiz competition at the start of the lesson challenges their recall of the structure of these lipids so that they can recognise the similarities and differences to the structure of phospholipids. Time is taken to look at the differing properties of the phosphate head and the fatty acid tails in terms of water and the class is challenged to work out how the phospholipids must be arranged when there’s an aqueous solution on the inside and outside of the cell. This introduces 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 fused 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 ultrastructure of eukaryotic cells and the functions of each of the organelles in these cells. The engaging and detailed PowerPoint and accompanying resources have been designed to cover points 3.1, 3.2 & 3.3 of the Edexcel International A-level Biology specification and therefore this lesson also describes how all living organisms are made of cells and that these cells are organised into tissues, organs and organ system in multicellular organisms. 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 Edexcel course and intricate planning has ensured that links to previously covered topics as well as upcoming ones are made throughout the lesson. The cell theory is introduced at the start of the lesson and the first 2 principles are explained. Students will see how epithelial cells are grouped together to form different types of epithelium in the respiratory tract and their prior knowledge of gas exchange at the alveoli from topic 2 is tested with a series of questions. The rest of the lesson uses a wide range of activities, that include exam-style questions, class discussion points and quick quiz competitions, to maintain motivation and engagement whilst describing the relationship between the structure and function of the following organelles: nucleus nucleolus centrioles ribosomes rough endoplasmic reticulum Golgi apparatus lysosomes smooth endoplasmic reticulum mitochondria cell surface membrane 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 go through all of the tasks

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 lesson describes the organisation of the mammalian nervous system, focusing on the CNS and the numerous divisions and subdivisions of the PNS. The PowerPoint and accompanying resource have been planned to cover the content of points 9.4 (i) and (iv) of the Edexcel A-level biology B specification. The lesson begins by challenging the students to recognise 6 organ systems from their descriptions, with the final description relating to the nervous system. A prior knowledge check of the classification topic introduces the lesson topic as the structure of the mammalian nervous system and then the lesson moves through the different divisions, completing the diagram in the cover image as each one is explored. The brain, spinal cord, neurones and autonomic nervous system are described in depth in upcoming lessons, so this lesson has been designed to introduce key information and to challenge students to build on the details they have from GCSE studies!

This lesson focuses on the structure of the spinal cord but also introduces key nervous system structures to prepare students for upcoming topic 9 lessons. The PowerPoint and accompanying resource have been planned to cover the content of point 9.4 (ii) of the Edexcel A-level biology B specification. As shown on the cover image, the lesson begins with a challenge, where students must use their knowledge of content from earlier topics to reveal 5 numbers that add up to 33. They will learn that this is the normal number of vertebrae in the human vertebral column and this leads into the recognition that these bones act to surround and protect the spinal cord. The meninges are introduced and then a quick quiz round is used to reveal the term, grey matter. Students will see that this is found in the centre of the spinal cord and is surrounded by an outer region of white matter. The idea of myelination is introduced, and initial details provided about the increased conductance speed in myelinated neurones because of saltatory conduction. Moving forwards, students will meet the terms dorsal and ventral and see on a diagram that nerves enter and leave the cord by these roots. The role of cerebrospinal fluid is explored and a series of exam-style questions are used to challenge their knowledge from topic 2 and 6 as well as their mathematical skills. The answers are embedded into the PowerPoint to allow the students to assess their progress. The lesson finishes with the introduction of the cauda equina as the bundle of nerves at the distal end of the spinal cord.

This lesson explains how to calculate the mitotic index and then explores what a high value may indicate about the tissue that was sampled. The PowerPoint and accompanying resources are part of the 2nd lesson in a series of 3 which have been planned to cover the content of point 2.2 of the AQA A-level biology specification. As shown in the cover image, the lesson begins with a bit of fun, as the students are challenged to use three clues to identify three uses of the term index in biology. They’ll learn that the index of diversity is covered in a topic 4 lesson and that this lesson focuses on the mitotic index. The students are challenged on their knowledge of the mitotic cell cycle throughout the lesson and one of these questions is used to introduce the meaning of the index and the formula. A series of exam-style questions challenge them to apply their understanding, and the answers are embedded into the PowerPoint to enable the students to assess their progress. Moving forwards, the different meanings of high values are considered, including growing and repairing tissues, and then to explain how an elevated mitotic index can indicate that cell division has become uncontrolled. This prepares students for the next lesson where tumour formation and cancer will be covered.

This lesson guides students through the calculation of mitotic indices and explores what a high value may indicate about the sampled tissue. The PowerPoint and accompanying resources have been planned to cover the content of point 3.16 of the Edexcel International A-level biology specification. The lesson begins with a bit of fun, as the students are challenged to use three clues to identify three uses of the term index in biology. They’ll learn that the index of diversity is covered in a topic 4 lesson and that this lesson focuses on the mitotic index. The students are challenged on their knowledge of the mitotic cell cycle throughout the lesson and one of these questions is used to introduce the meaning of the index and the formula. A series of exam-style questions challenge them to apply their understanding, and the answers are embedded into the PowerPoint to enable the students to assess their progress. Moving forwards, the different meanings of high values are considered, including growing and repairing tissues, and then to explain how an elevated mitotic index can indicate that cell division has become uncontrolled which can lead to tumour formation.