This detailed lesson describes how the movement of water between solutions and cells has differing effects on animal and plant cells. Both the PowerPoint and accompanying resources have been designed to cover specification points 4.2 (a) and (f) as detailed in the CIE International A-level Biology specification. 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 fully-resourced lesson compares the structure and ultrastructure of a prokaryotic cell against an eukaryotic cell. The engaging PowerPoint and accompanying resources have been designed to cover specification point 2.1.1 (k) as detailed in the OCR A-level Biology A specification and describes how the size and cell structures differ as well as the additional features that are found in some prokaryotic cells and briefly introduces binary fission. 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 these cells do not contain centrioles

This engaging lesson describes how chromosome mutations result in changes to the number or structure of chromosomes and focuses on Downs and Turner’s syndrome. The PowerPoint and accompanying resources have been designed to cover specification points 2.3 (vi) and (vii) as detailed in the Edexcel A-level Biology B specification. A human karyotype which has not been altered by a mutation is studied at the start of the lesson to allow students to recall the usual number of chromosomes as well as the sex chromosomes. They are then challenged to identify the differences when presented with the karyotypes of sufferers of Downs, Turner’s and Klinefelter’s syndrome. Students will learn that in the majority of cases, these conditions are the result of non-disjunction and having been assisted in the explanation of the outcome for Downs and Klinefelters, they have to form their own for Turner’s. The remainder of the lesson looks at other types of mutations, including translocation, and students will also see how whole sets of chromosomes can be duplicated in polyploidy.

This fully-resourced lesson describes how it’s possible for 1 gene to give rise to multiple products as a result of post-transcriptional modification of mRNA. The detailed PowerPoint and accompanying resources have been designed to cover point 7.2 (iii) of the Edexcel A-level Biology B specification. 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 1 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 fully-resourced lesson describes the role of transcription factors in the regulation of gene expression. The detailed PowerPoint and accompanying resources have been designed to cover the details of specification points 7.2 (i) and (ii) of the Edexcel A-level Biology B 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 1.4, 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. Their understanding is then tested again with another example with oestrogen and the ER receptor. The final and 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.

This lesson describes the structure and mode of action of phagocytes and focuses on the neutrophils and macrophages as APCs. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 4.1.1 (e) [i] of the OCR A-level Biology A specification and also includes an introduction to antigen-presentation so that the students are prepared for the next lesson on the specific immune response 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 response is made.

This fully-resourced lesson has been written to support students to develop a clear understanding of 16 key genetic terms, including the 8 that are detailed in specification point 8.2 (i) of the Edexcel A-level Biology B specification. The 16 terms are genome, gene, chromosome, gene locus, homologous chromosomes, alleles, dominant, recessive, genotype, codominance, multiple alleles, autosomes, sex chromosomes, phenotype, homozygous and heterozygous. As some of these terms were met at GCSE, this fully-resourced lesson has been designed to include a wide range of activities that build on this prior knowledge and provide clear explanations as to their meanings as well as numerous examples of their use in both questions and exemplary answers. The main task provides the students with an opportunity to apply their understanding by recognising a dominance hierarchy in a multiple alleles characteristic and then calculating a phenotypic ratio when given a completed genetic diagram. Other tasks include prior knowledge checks, discussion points to encourage students to consider the implementation of the genetic terms and quiz competitions to introduce new terms, maintain engagement and to act as an understanding check.

This detailed lesson describes the fluid mosaic model of membrane structure and also describes the roles of its components. The detailed and engaging PowerPoint and accompanying worksheets have been designed to cover specification point 2.1.5 (b) of the OCR A-level Biology A specification and clear links are made to related topics such as the binding of peptide hormones 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 module 2.1.2 and 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 how selection pressures act on a gene pool and cause stabilising, directional and disruptive selection. The PowerPoint and accompanying resources have been designed to cover point 8.3 (i) of the Edexcel A-level Biology B specification which states that students should be able to identify each type of selection by its effect on different phenotypes. The lesson begins with an introduction to the mark, release, recapture method to calculate numbers of rabbits with different coloured fur in a particular habitat. This shows changes in numbers of the organisms and sketch graphs are then constructed to show these changes in the population size. A quick quiz competition is used to engage the students whilst introducing the names of the three main types of selection before a class discussion point encourages the students to recognise which specific type of selection is represented by the rabbits. Key terminology including intermediate and extreme phenotypes and selection pressure are used to emphasise their importance during explanations. A change in the environment of the habitat and a change in the numbers of the rabbits introduces directional selection before students will be given time to discuss and to predict the shape of the sketch graph for disruptive selection. Students are challenged to apply their knowledge in the final task of the lesson by choosing the correct type of selection when presented with details of a population and answer related questions.

This fully-resourced lesson describes the blood clotting process and includes the release of thromboplastin and the subsequent conversions to thrombin and fibrin. The engaging PowerPoint and accompanying worksheets have been primarily designed to cover the content detailed in point 1.6 of the Pearson Edexcel A-level Biology A specification but time has been taken to look at haemophilia as a sex-linked disease so that students are prepared for sex-linkage when covered 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.

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 engaging lesson uses the example of resistant bacteria and the modern-day giraffe to describe how natural selection occurs. The PowerPoint and accompanying resources have been designed to cover point 17.2 (a) of the CIE A-level Biology specification but also explains that genetic diversity is important for selection and therefore covers 17.1 (d) at the same time. President Trump’s error ridden speech about viruses antibiotics is used at the beginning of the lesson to remind students antibiotics are actually a treatment for bacterial infections. Moving forwards, 2 quick quiz competitions will initially introduce MRSA and then will show the students that they can use this abbreviation to remind them to use mutation, reproduce, selection (and survive) and allele in their descriptions of evolution through natural selection. The main task of the lesson challenges the students to form a description that explains how this strain of bacteria developed resistance to methicillin. In doing so, they will see the principles of natural selection so they can be applied to different situations such as describing how the anatomy of the modern-day giraffe has evolved over time. The final part of the lesson introduces adaptations and convergent evolution and also links to the need for modern classification techniques which is covered later in topic 17.

As the monomers of proteins, amino acids are extremely important and this lesson describes their structure and roles in organisms. The engaging PowerPoint has been designed to cover point (h) as detailed in AS unit 1, topic 1 of the WJEC A-level Biology specification and provides a clear introduction to the following lesson on the protein structures. 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, before cysteine is considered in greater detail due to the presence of sulfur atoms. Students are briefly introduced to disulfide bridges so they will recognise how particular bonds form between the R groups in the tertiary structure which is covered in the next lesson. One more quiz round called LINK TO THE FUTURE is used to demonstrate the range of roles played by amino acids in the later part of the course such as translation and mineral ions. The final part of the lesson considers challenges the students on their knowledge of hydrolysis reactions as they have to spot the errors in a passage about the breakdown of polypeptides and dipeptides.

This fully-resourced lesson describes how DNA is replicated semi-conservatively, including the roles of DNA helicase, polymerase and ligase. The detailed PowerPoint and accompanying resources have been designed to cover point 1.4 (ii) of the Edexcel A-level Biology B specification The main focus of this lesson is the roles of DNA helicase in the breaking of the hydrogen bonds between nucleotide bases, DNA polymerase in forming the growing nucleotide strands and DNA ligase in the joining of the nucleic acid fragments. Time is taken to explain key details, such as the assembly of strands in the 5’-to-3’ direction, so that the continuous manner in which the leading strand is synthesised can be compared against that of the lagging strand. The students are constantly challenged to make links to previous topics such as DNA structure and hydrolysis reactions through a range of exam questions and answers are displayed so that any misconceptions are quickly addressed. The main task of the lesson asks the students to use the information provided in the lesson to order the sequence of events in DNA replication before discussing how the presence of a conserved strand and a newly built strand in each new DNA molecule shows that it is semi-conservative.

This detailed lesson describes the properties of water to demonstrate the importance of this molecule for living organisms. The engaging PowerPoint and accompanying resource have been designed to cover the details of specification point (b) of AS unit 1, topic 1 of the WJEC A-level Biology course and has been specifically designed to ensure that each role is illustrated using a specific example. As this is only the second lesson in the biological compounds topic, which is a topic that students tend to find difficult or potentially less engaging, the planning has centred around the inclusion of a wide variety of tasks to cover the content whilst maintaining motivation and engagement. These tasks include current understanding and prior knowledge checks, discussion points and quick quiz competitions to introduce key terms and values in a memorable way. The start of the lesson considers the structure of water molecules, focusing on the covalent and hydrogen bonds, and the dipole nature of this molecule. Time is taken to emphasise the importance of these bonds and this property for the numerous roles of water and then over the remainder of the lesson, the following properties are described and discussed and linked to real-life examples: polarity ability to form hydrogen bonds surface tension as a solvent thermal properties as a metabolite The final part of the lesson introduces condensation and hydrolysis reactions and students will learn that a clear understanding of these reactions is critical as they will reappear throughout the topic in the synthesis and breakdown of biological compounds

This detailed lesson describes the process of translation at the ribosome and includes detailed descriptions of the roles of the mRNA, tRNA and rRNA. The PowerPoint and accompanying resources have been designed to cover the second part of point 1.4 (vi) of the Edexcel A-level Biology B specification and this lesson also includes continual links to the previous lessons in this topic on transcription and the structure of DNA and RNA. Translation is a topic which is often poorly understood and so this lesson has been written with the aim of supporting the students to answer the different types of questions that can arise. The lesson begins by challenging the students to consider why it is so important that the amino acids are assembled in the correct order during the formation of the chain. Moving forwards, a quick quiz round called “LOST IN TRANSLATION” is used to check on their prior knowledge of the mRNA strand, the tRNA molecules and the ribosomes. The next task involves a very detailed description of translation that has been divided into 14 statements which the students have to put into the correct order. By giving them a passage of this detail, they can pick out the important parts to use in the next task where they have to answer shorter questions worth between 3 and 4 marks. These types of questions are common in the assessments and by building up their knowledge across the lesson, their confidence to tackle this type of question should increase. The final two tasks of the lesson involve another quiz, where the teams compete to transcribe and translate in the quickest time before using all that they have absorbed to answer some questions which involve the genetic code and the mRNA codon table

This fully-resourced lesson describes the different effects that gene mutations can have on the amino acid sequence of a protein. The engaging and detailed PowerPoint and accompanying resources have been designed to cover points 1.4 (viii) & (ix) as detailed in the Edexcel A-level Biology B specification and includes substitutions, deletions and insertions and considers a real life example in sickle cell anaemia. In order to understand how a change in the base sequence can affect the order of the amino acids, students must be confident in their understanding and application of protein synthesis which was covered earlier in this topic. Therefore, the start of the lesson focuses on transcription and translation and students are guided through the use of the codon table to identify amino acids. Moving forwards, a task called known as THE WALL is used to introduce to the names of three types of gene mutation whilst challenging the students to recognise three terms which are associated with the genetic code. The main focus of the lesson is substitutions and how these mutations may or may not cause a change to the amino acid sequence. The students are challenged to use their knowledge of the degenerate nature of the genetic code to explain how a silent mutation can result. Students will learn that a substitution is responsible for the new allele that causes sickle cell anaemia and they are tested on their understanding through an exam-style question. As with all of the questions, a mark scheme is included in the PowerPoint which can be displayed to allow the students to assess their understanding. The rest of the lesson looks at base deletions and base insertions and students are introduced to the idea of a frameshift mutation. One particular task challenges the students to evaluate the statement that base deletions have a bigger impact on primary structure than base substitutions. This is a differentiated task and they have to compare the fact that the reading frame is shifted by a deletion against the change in a single base by a substitution

This detailed lesson describes the importance of the dipole nature of water and its numerous properties to living organisms. The engaging PowerPoint and accompanying resource have been designed to cover the details of specification point 1.7 of the Edexcel A-level Biology B course and the intricate planning ensures that each role is illustrated using a specific example. As the final lesson in the biological molecules topic, not only does this lesson cover the important content related to water but also acts as a revision tool as it checks on key topic 1 content such as condensation and hydrolysis reactions. A wide range of tasks are used to check on current understanding and prior knowledge and quick quiz competitions introduce key terms and values in a memorable way. The start of the lesson considers the structure of water molecules, focusing on the covalent and hydrogen bonds, and the dipole nature of this molecule. Time is taken to emphasise the importance of these bonds and this property for the numerous roles of water and then over the remainder of the lesson, the following properties are described and discussed and linked to real-life examples: high specific heat capacity polar solvent surface tension incompressibility maximum density at 4 degrees Celsius