This detailed lesson describes osmosis as the movement of free water molecules through a partially permeable membrane, down the water potential gradient. The engaging PowerPoint and accompanying resources have been designed to cover the details of specification point 2.4 of the Edexcel International A-level Biology specification and also describes the effect 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 iGCSE, 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, down 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 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 lesson describes how to use the magnification formula to calculate the magnification or the actual size in a range of units. The PowerPoint and accompanying resources have been designed to cover the 3rd part of point 2.1.3 of the AQA A-level Biology specification The students are likely to have met the magnification formula at GCSE so this lesson has been written to build on that knowledge and to support them with more difficult questions when they have to calculate actual size without directly being given the magnification. A step by step guide is used to walk the students through the methodology and useful tips are provided. Students could be asked to calculate the actual size in millimetres, micrometres, nanometres or picometres so time is taken to ensure that they can convert between one and another. This lesson has been written to tie in with the previous two lessons on microscopes and measuring the size of an object and the two rounds of the ongoing quiz competition take place in this lesson.

This lesson describes how the eyepiece graticule and stage micrometer are used to measure the size of an object with an optical microscope. The PowerPoint and accompanying resource have been designed to cover the second part of point 2.1.3 of the AQA A-level Biology specification The main task of this concise lesson involves a step by step guide which walks students through the methodology and the use of the scale on the stage micrometer to identify the size of the divisions of the eyepiece graticule. This will need them to convert between units and as this was covered in the previous lesson, a number of prior knowledge checks will check that they are able to do this. Moving forwards, the students are challenged to apply this method to a series of exam-style questions and the mark scheme is displayed on the PowerPoint so that they can assess their understanding.

This fully-resourced lesson describes the principles and limitations of optical, transmission electron and scanning electron microscopes. The engaging PowerPoint and accompanying resources have been designed to cover the specification details at the start of topic 2.1.3 of the AQA A-level Biology course and also explains the difference between magnification and resolution. When designing all four of the lessons to cover the detail of 2.1.3, I was conscious that microscopes and the methods of studying cells is a topic that doesn’t always attract the full attention of the students. In line with this, I aimed to plan lessons that encouraged engagement so that the likelihood of knowledge retention and understanding was increased. An ongoing quiz competition runs across the 4 lessons and in this particular lesson, rounds such as YOU DO THE MATH and IT’S TIME FOR ACTION will introduce key terms and values in a fun and memorable way. Time is taken to look at the key details of each of the types of microscope and students will be able to describe how light or the transmission of electrons through or across a specimen will form an image. Students will come to recognise the difference between magnification and resolution and examples are provided and exam-style questions used to check on understanding. As well as current understanding checks, prior knowledge checks challenge the students to make links to other biological topics which include specialised cells and tissues, cell structures and biological molecules. As detailed above, this lesson has been written to be the first in a series of 4 lessons and the others, which are uploaded are: Measuring the size of an object viewed under an optical microscope Use of the magnification formula Cell fractionation and ultracentrifugation

This lesson describes how to use the magnification formula to calculate the actual sizes of specimens in a range of units. The PowerPoint and accompanying resources have been designed to cover point 1.1 (e) of the CIE A-level Biology specification but can also be used as a revision tool on the content of the previous two lessons as prior knowledge checks are included along with current understanding checks. The students are likely to have met the magnification formula at iGCSE so this lesson has been written to build on that knowledge and to support them with more difficult questions when they have to calculate actual size without directly being given the magnification. A step by step guide is used to walk the students through the methodology and useful tips are provided. The final quiz round of the competition that has run over the course of these 3 lessons will challenge them to convert between units so they are confident when challenged to present actual size in millimetres, micrometres or nanometres.

This fully-resourced lesson describes the differences between resolution and magnification, with reference to light and electron microscopy and the engaging PowerPoint and accompanying resources have been designed to cover the content of point 1.1 (d) of the CIE A-level Biology specification. To promote engagement and focus throughout these 3 lessons in topic 1.1 (The microscope in cell studies), the PowerPoint includes an ongoing quiz competition and a score sheet is found within the resources to keep track of the cumulative scores. The quiz rounds found in this lesson will introduce the objective lens powers, the names of the parts of a light microscope and emphasise some of the other key terms such as resolution. The final round checks on their understanding of the different numbers that were mentioned in the lesson, namely the differing maximum magnifications and resolutions. Time is taken to explain the meaning of both of these microscopic terms so that students will understand their importance when looking at the cell structures in topic 1.2. By the end of the lesson, the students will be able to explain how a light microscope uses light to form an image and will understand how electrons transmitted through a specimen or across the surface will form an image with a TEM or a SEM respectively. As detailed above, this lesson has been written to tie in with the previous lesson on measuring cells and units as well as the next lesson on calculating actual size.

This lesson describes how the eyepiece graticule and stage micrometer are used in the measurement of cells. The engaging PowerPoint and accompanying resources have been designed to cover point 1.1 [c] of the CIE A-level Biology specification and also includes a number of tasks that have been written to ensure that students are able to recognise the millimetre, micrometre and nanometre as units of size and that they are able to convert between them. As this content is part of topic 1.1, it is likely that this lesson on the measurement of cells and the units of size will be one of the first that students will encounter in this A-level course. With this in mind, this lesson and the next two on microscopes and calculating actual size have been specifically written to contain a wide variety of tasks, including an ongoing quiz competition. This will act to maintain engagement in a topic that can sometimes discourage students at this early stage of the course whilst ensuring that the key content is covered and understanding is constantly checked. A step by step guide walks them through the use of the scale on the stage micrometer to identify the size of the divisions of the eyepiece graticule and then they are challenged to apply this method to a series of questions. Useful hints are provided throughout the lesson and students will be able to confidently convert between metres, millimetres, micrometres and nanometres by the end of the lesson A quiz scoresheet is included with the lesson so that teachers can keep track of the points won in the different rounds and add them to those won in the upcoming lessons in topic 1.1

This fully-resourced lesson describes how carbon dioxide, light intensity and temperature limit the rate of photosynthesis. The PowerPoint and accompanying resources have been designed to cover point 5.7 (viii) of the Edexcel A-level Biology B specification The lesson has been specifically written to tie in with the four previous lessons in this topic which covered the structure of the chloroplast, the light-dependent and light-independent stages and GALP as a raw material. Exam-style questions are included throughout the lesson and these require the students to explain why light intensity is important for both reactions as well as challenging them on their ability to describe how the relative concentrations of GP, GALP and RuBP would change as carbon dioxide concentration decreases. There are also links to previous topics such as enzymes when they are asked to explain why an increase in temperature above the optimum will limit the rate of photosynthesis. Step by step guides are included to support them to form some of the answers and mark schemes are always displayed so that they can quickly assess their understanding and address any misconceptions

This fully-resourced lesson describes how GALP is used as a raw material in the production of monosaccharides, amino acids and other molecules. The engaging and detailed PowerPoint and accompanying resources have been primarily designed to cover point 5.7 (vii) of the Edexcel A-level Biology B specification concerning the uses of GALP but as the lesson makes continual references to biological molecules, it can act as a revision tool for a lot of the content of topic 1. The previous lesson covered the light-independent stage and this lesson builds on that understanding to demonstrate how the product of the Calvin cycle, glyceraldehyde phosphate, is used. The start of the lesson challenges the students to identify two errors in a diagram of the cycle so that they can recall that most of the GALP molecules are used in the regeneration of ribulose bisphosphate. A quiz version of Pointless runs throughout the lesson and this is used to challenge the students to recall a biological molecule from its description. Once each molecule has been revealed, time is taken to go through the details of the formation and synthesis of this molecule from GALP or from GP in the case of fatty and amino acids. The following molecules are considered in detail during this lesson: glucose (and fructose and galactose) sucrose starch and cellulose glycerol and fatty acids amino acids nucleic acids A range of activities are used to challenge their prior knowledge of these molecules and mark schemes are always displayed for the exam-style questions to allow the students to assess their understanding. As detailed above, this lesson has been specifically written to tie in with the earlier lessons in this module on the structure of the chloroplast and the light-dependent and light-independent stages of photosynthesis.

This fully-resourced lesson describes how light intensity, carbon dioxide concentration and temperature limit the rate of photosynthesis. The PowerPoint and accompanying resources have been designed to cover point 5.2.1 (g) (i) of the OCR A-level Biology A specification and also includes a brief consideration of water stress. The lesson has been specifically written to tie in with the three previous lessons in this module which covered the structure of the chloroplast, the light-dependent and light-independent stages and the uses of TP. Exam-style questions are included throughout the lesson and these require the students to explain why light intensity is important for both reactions as well as challenging them on their ability to describe how the relative concentrations of GP, TP and RuBP would change as carbon dioxide concentration decreases. There are also links to previous topics such as enzymes when they are asked to explain why an increase in temperature above the optimum will limit the rate of photosynthesis. Step by step guides are included to support them to form some of the answers and mark schemes are always displayed so that they can quickly assess their understanding and address any misconceptions.

This fully-resourced lesson describes how TP is a starting material for the synthesis of carbohydrates, lipids and amino acids as well as being recycled to regenerate RuBP in the Calvin cycle. The engaging and detailed PowerPoint and accompanying resources have been primarily designed to cover point 5.2.1 (f) of the OCR A-level Biology A specification concerning the uses of TP but as the lesson makes continual references to biological molecules, it can act as a revision tool for the content of module 2.1.2. The previous lesson covered the light-independent stage and this lesson builds on that understanding to demonstrate how the product of the Calvin cycle, triose phosphate, is used. The start of the lesson challenges the students to identify two errors in a diagram of the cycle so that they can recall that most of the TP molecules are used in the regeneration of ribulose bisphosphate. A quiz version of Pointless runs throughout the lesson and this is used to challenge the students to recall a biological molecule from its description. Once each molecule has been revealed, time is taken to go through the details of the formation and synthesis of this molecule from TP or from GP in the case of fatty and amino acids. The following molecules are considered in detail during this lesson: glucose sucrose starch and cellulose glycerol and fatty acids amino acids nucleic acids A range of activities are used to challenge their prior knowledge of these molecules and mark schemes are always displayed for the exam-style questions to allow the students to assess their understanding. As detailed above, this lesson has been specifically written to tie in with the earlier lessons in this module on the structure of the chloroplast and the light-dependent and light-independent stages of photosynthesis.

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

This lesson describes the mechanism of breathing, including the roles of the ribcage, intercostal muscles and the diaphragm. The content of the engaging PowerPoint has been designed to cover the details of the fifth part of specification point 3.2 of the AQA A-level Biology specification and introduces the antagonistic interaction of the external and internal intercostal muscles. The lesson begins with a focus on the diaphragm and students will discover that this sheet of muscle is found on the floor of the thoracic cavity. Whilst planning the lesson, it was deemed important to introduce this region of the body at an early stage because the best descriptions will regularly reference the changes seen in this cavity. As the mechanism of inhalation is a cascade of events, the details of this process are covered in a step by step format using bullet points. At each step, time is taken to discuss the key details which includes an introduction to Boyle’s law that reveals the inverse relationship between volume and pressure. It is crucial that students are able to describe how the actions of the diaphragm, external intercostal muscles and ribcage result in an increased volume of the thoracic cavity and a subsequent decrease in the pressure, which is below the pressure outside of the body. At this point, their recall of the structures of the mammalian gas exchange system is tested, to ensure that they can describe the pathway the air takes on moving into the lungs. The remainder of the lesson involves a task which challenges the students to describe exhalation and then the accessory muscles involved in forced ventilation are also considered.