This lesson describes the evidence that led to the three-domain model of classification as an alternative to the five-kingdom model. The detailed PowerPoint and accompanying resources have been designed to cover point 3.1 (vii) of the Edexcel A-level Biology B specification and focuses on Carl Woese’s detailed study of the ribosomal RNA gene and the need for this evidence to be validated by the scientific community The lesson begins with an introduction of Woese and goes on to describe how he is most famous for his definition of the Archaea as a new domain of life. Students were introduced to domains and the other classification taxa in a lesson at the start of this topic, so their recall of this knowledge is continually tested and built upon as details are added. Students will discover the key differences between Archaea and Bacteria that led to the splitting of the prokaryotae kingdom and the addition of this higher classification rank and will understand that it wasn’t until 13 years after the discovery that it was adopted. Moving forwards, the rest of the lesson describes how molecular phylogeny uses other molecules that can be compared between species for classification purposes. One of these is a protein called cytochrome which is involved in respiration and can be compared in terms of primary structure to determine relationships. At this point in the lesson, the students are also tested on their knowledge of the nature of the genetic code (as covered in topic 1) and have to explain how mutations to DNA can also be used for comparative purposes.

This lesson describes how the critical evaluation of new data by the scientific community leads to new taxonomic groupings, like the three domains of life. The detailed PowerPoint and accompanying resources have been designed to cover point 4.14 (ii) of the Edexcel International A-level Biology specification and focuses on the introduction of the three-domain system following Carl Woese’s detailed study of the ribosomal RNA gene. The lesson begins with an introduction of Woese and goes on to describe how he is most famous for his definition of the Archaea as a new domain of life. Students were introduced to domains and the other classification taxa in a previous lesson, so their recall of this knowledge is continually tested and built upon as details are added. Students will discover the key differences between Archaea and Bacteria that led to the splitting of the prokaryotae kingdom and the addition of this higher classification rank. Moving forwards, the rest of the lesson describes how molecular phylogeny uses other molecules and that these are compared between species for classification purposes. One of these is a protein called cytochrome which is involved in respiration and can be compared in terms of primary structure to determine relationships. At this point in the lesson, the students are also tested on their knowledge of the nature of the genetic code (as covered in topic 2) and have to explain how mutations to DNA can also be used for comparative purposes.

This lesson describes classification as a means of organising the variety of life based on relationships between organisms. The engaging PowerPoint and accompanying resource have been designed to cover point 4.14 (i) of the Edexcel International A-level Biology specification and focuses on the classification hierarchy where species is the lowest taxon but also describes the binomial naming system which uses the genus and species. The lesson also contains links to the next lesson where molecular phylogeny is described and the three-domain system is covered in greater detail with a focus on the results of Carl Woese’s rRNA study The lesson begins by looking at the meaning of a population in Biology so that the term species can be introduced. A hinny, which is the hybrid offspring of a horse and a donkey, is used to explain how these two organisms must be members of different species because they are unable to produce fertile offspring. Moving forwards, students will learn that classification is a means of organising the variety of life based on relationships between organisms using differences and similarities in phenotypes and in genotypes and is built around the species concept and that in the modern-day classification hierarchy, species is the lowest taxon. A quiz runs throughout the lesson and this particular round will engage the students whilst they learn (or recall) the names of the other 7 taxa and the horse and the donkey from the earlier example are used to complete the hierarchy. Students will understand that the binomial naming system was introduced by Carl Linnaeus to provide a universal name for each species and they will be challenged to apply their knowledge by completing a hierarchy for a modern-day human, by spotting the correct name for an unfamiliar organism and finally by suggesting advantages of this system.

This lesson describes how the critical evaluation of new data by the scientific community leads to new taxonomic groupings, like the three domains of life. The detailed PowerPoint and accompanying resources have been designed to cover point 4.6 (ii) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and focuses on the introduction of the three-domain system following Carl Woese’s detailed study of the ribosomal RNA gene. The lesson begins with an introduction of Woese and goes on to describe how he is most famous for his definition of the Archaea as a new domain of life. Students were introduced to domains and the other classification taxa in a previous lesson, so their recall of this knowledge is continually tested and built upon as details are added. Students will discover the key differences between Archaea and Bacteria that led to the splitting of the prokaryotae kingdom and the addition of this higher classification rank. Moving forwards, the rest of the lesson describes how molecular phylogeny uses other molecules and that these are compared between species for classification purposes. One of these is a protein called cytochrome which is involved in respiration and can be compared in terms of primary structure to determine relationships. At this point in the lesson, the students are also tested on their knowledge of the nature of the genetic code (as covered in topic 2) and have to explain how mutations to DNA can also be used for comparative purposes.

This lesson describes the classification system, focusing on the biological classification of a species and the 7 taxa found above this lowest taxon. The engaging PowerPoint and accompanying resource have been designed to cover point 4.6 (i) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and also describes the binomial naming system which uses the genus and species. The lesson also contains links to upcoming lessons where molecular phylogeny is described and the three-domain system is covered in greater detail with a focus on the results of Carl Woese’s rRNA study The lesson begins by looking at the meaning of a population in Biology so that the term species can be introduced. A hinny, which is the hybrid offspring of a horse and a donkey, is used to explain how these two organisms must be members of different species because they are unable to produce fertile offspring. Moving forwards, students will learn that classification is a means of organising the variety of life based on relationships between organisms using differences and similarities in phenotypes and in genotypes and is built around the species concept and that in the modern-day classification hierarchy, species is the lowest taxon. A quiz runs throughout the lesson and this particular round will engage the students whilst they learn (or recall) the names of the other 7 taxa and the horse and the donkey from the earlier example are used to complete the hierarchy. Students will understand that the binomial naming system was introduced by Carl Linnaeus to provide a universal name for each species and they will be challenged to apply their knowledge by completing a hierarchy for a modern-day human, by spotting the correct name for an unfamiliar organism and finally by suggesting advantages of this system.

This lesson describes how the recent use of similarities in biological molecules and other genetic evidence has led to new classification systems. The PowerPoint and accompanying resources have been designed to cover point 4.2.2 [c] (i) of the OCR A-level Biology A specification and focuses on the introduction of the three-domain system following Carl Woese’s detailed study of the ribosomal RNA gene. The lesson begins with an introduction of Woese and goes on to describe how he is most famous for his definition of the Archaea as a new domain of life. Students were introduced to domains and the other classification taxa in a previous lesson, so their recall of this knowledge is continually tested and built upon as details are added. Students will discover the key differences between Archaea and Bacteria that led to the splitting of the prokaryotae kingdom and the addition of this higher classification rank. Moving forwards, the rest of the lesson considers other molecules that can be compared between species for classification purposes and the primary structure of cytochrome is described and discussed. At this point in the lesson, the students are also tested on their knowledge of the nature of the genetic code and have to explain how mutations to DNA can also be used for comparative purposes.

This lesson describes the biuret and emulsion tests for proteins and lipids respectively and then acts as a revision lesson for topics 2.2 and 2.3. The engaging PowerPoint and accompanying resources have been designed to be taught at the end of topic 2 and uses a range of activities to challenge the students on their knowledge of that topic, but also covers the second part of point 2.1 (a) of the CIE A-level Biology specification when the qualitative tests are described. The first section of the lesson describes the steps in the biuret test and challenges the students on their recall of the reducing sugars and starch tests from topic 2.1 to recognise that this is a qualitative test that begins with the sample being in solution. The students will learn that the addition of sodium hydroxide and then copper sulphate will result in a colour change from light blue to lilac if a protein is present. The next part of the lesson uses exam-style questions with displayed mark schemes, understanding checks and quick quiz competitions to engage and motivate the students whilst they assess their understanding of this topic. The following concepts are tested during this lesson: The general structure of an amino acid The formation of dipeptides and polypeptides through condensation reactions The primary, secondary, tertiary and quaternary structure of a protein Biological examples of proteins and their specific actions (e.g. antibodies, enzymes, peptide hormones) Moving forwards, the lesson describes the key steps in the emulsion test for lipids, and states the positive result for this test. There is a focus on the need to mix the sample with ethanol, which is a distinctive difference to the tests for reducing sugars and starch and proteins. The remainder of the lesson uses exam-style questions with mark schemes embedded in the PowerPoint, understanding checks, guided discussion points and quick quiz competitions to challenge the following specification points: The structure of a triglyceride The relationship between triglyceride property and function The hydrophilic and hydrophobic nature of the phospholipid The phospholipid bilayer of the cell membrane Cholesterol is also introduced so that the students are prepared for this molecule when it is met in topic 4 (cell membranes) This is an extensive lesson and it is estimated that it will take in excess of 2 hours of allocated teaching time to cover the detail and the different tasks

This lesson explains the effects of light intensity, carbon dioxide concentration and temperature (limiting factors) on the rate of photosynthesis. The PowerPoint and accompanying resources have been designed to cover points 13.2 (a, b & c) of the CIE A-level Biology specification and also considers how knowledge of these limiting factors can be used to increase crop yields in the protected environment of a greenhouse. The lesson has been specifically written to tie in with the previous lessons in topic 13.1 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. The final part of the lesson provides details of the World’s largest rooftop greenhouse in Montreal and challenges their knowledge of related topics such as cellulose structure, pollination and biological control.

This lesson describes the function of transcription factors in eukaryotes and uses the lac operon to explain the control of protein production in a prokaryote. The detailed PowerPoint and accompanying resources have been designed to cover points 16.3 (b, c & d) as detailed in the CIE A-level Biology specification and also includes a description of how gibberellin breaks down DELLA protein repressors, allowing transcription to be promoted. 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 6, so the lesson begins by reminding students that in addition to the structural gene in a transcription unit, there is the promoter 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 and immediately an opportunity is taken to challenge their knowledge of biological molecules with a task where they have to spot the errors in a passage describing the formation and breakdown of this disaccharide. Students will be able to visualise the different structures that are found in this operon 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 behaviour of chromosomes during meiosis, focusing on the events which contribute to genetic variation. The detailed PowerPoint and accompanying resources have been designed to cover points 16.1 (a, d & e) of the CIE A-level Biology specification and explains how crossing over, the random assortment and the random fusion of haploid gametes leads to variation. In order to understand how the events of meiosis like crossing over and independent assortment and independent segregation can lead to variation, students need to be clear in their understanding that DNA replication in interphase results in homologous chromosomes as pairs of sister chromatids. Therefore the beginning of the lesson focuses on the chromosomes in the parent cell and this first part of the cycle and students will be introduced to non-sister chromatids and the fact that they may contain different alleles which is important for the exchange that occurs during crossing over. Time is taken to go through this event in prophase I in a step by step guide so that the students can recognise that the result can be new combinations of alleles that were not present in the parent cell. Moving forwards, the lesson explores how the independent assortment and segregation of chromosomes and chromatids during metaphase I and II and anaphase I and II respectively results in genetically different gametes. The key events of all of the 8 phases are described and there is a focus on key terminology to ensure that students are able to describe genetic structures in the correct context. The final part of the lesson looks at the use of a mathematical expression to calculate the possible combinations of alleles in gametes as well as in a zygote following the random fertilisation of haploid gametes. Understanding and prior knowledge checks are interspersed throughout the lesson as well as a series of exam-style questions which challenge the students to apply their knowledge to potentially unfamiliar situations. This lesson has been specifically planned to link to the two lessons on the cell cycle and the main stages of mitosis as covered in topic 5 and constant references are made throughout to encourage students to make links and also to highlight the differences between the two types of nuclear division

This fully-resourced lesson describes the behaviour of chromosomes during the mitotic cell cycle and explains the importance of this type of nuclear division. The PowerPoint and accompanying resources have been designed to cover points 5.1 (b) & 5.2 (a) of the CIE A-level Biology specification and make direct links to a previous lesson which covered the outline of cell cycle Depending upon the exam board taken at iGCSE, the knowledge and understanding of mitosis 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 so that existing errors are addressed and key points are emphasised throughout. Their understanding of interphase is challenged at the start of the lesson to ensure that they realise that it is identical pairs of sister chromatids that enter the M phase. The main part of the lesson focuses on prophase, metaphase, anaphase and telophase and describes how the chromosomes behave in these stages. There is a focus on the centrioles and the spindle fibres that they produce which contract to drag one chromatid from each pair in opposite directions to the poles of the cell. The remainder of the lesson is 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 quiz 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 lesson describes the key events that occur during interphase, mitosis and cytokinesis in the eukaryotic cell cycle. The PowerPoint and accompanying resources have been designed to cover point 5.1 [c] of the CIE A-level Biology specification and challenges the students on their knowledge of chromosomes from an earlier lesson as well as preparing them for upcoming lessons on the main stages of mitosis and its significance in life cycles The students were introduced to the cell cycle at GCSE so this lesson has been planned to build on that knowledge and to emphasise that the M phase which includes mitosis (nuclear division) only occupies a small part of the cycle. The students will learn that interphase is the main stage and that this is split into three phases, G1, S and G2. A range of tasks which include exam-style questions, guided discussion points and quick quiz competitions are used to introduce key terms and values and to describe the main processes that occur in a very specific order. There is also a focus on the checkpoints, such as the restriction point that occurs before the S phase to ensure that the cell is ready for DNA replication. Extra time is taken to ensure that key terminology is included and understood, such as sister chromatid and centromere, and this focus helps to show how it is possible for genetically identical daughter cells to be formed at the end of the cycle. Important details of mitosis are introduced so students are ready for the next lesson, before the differences in cytokinesis in animal and plant cells are described.

This lesson describes the main stages of meiosis, focusing on the events which contribute to genetic variation and explains its significance in life cycles. The detailed PowerPoint and accompanying resources have been designed to cover points 2.1.6 (f) & (g) of the OCR A-level Biology A specification and includes description of crossing over, independent assortment, independent segregation and the production of haploid gametes In order to understand how the events of meiosis like crossing over and independent assortment and independent segregation can lead to variation, students need to be clear in their understanding that DNA replication in interphase results in homologous chromosomes as pairs of sister chromatids. Therefore the beginning of the lesson focuses on the chromosomes in the parent cell and this first part of the cycle and students will be introduced to non-sister chromatids and the fact that they may contain different alleles which is important for the exchange that occurs during crossing over. Time is taken to go through this event in prophase I in a step by step guide so that the students can recognise that the result can be new combinations of alleles that were not present in the parent cell. Moving forwards, the lesson explores how the independent assortment and segregation of chromosomes and chromatids during metaphase I and II and anaphase I and II respectively results in genetically different gametes. The key events of all of the 8 phases are described and there is a focus on key terminology to ensure that students are able to describe genetic structures in the correct context. The final part of the lesson looks at the use of a mathematical expression to calculate the possible combinations of alleles in gametes as well as in a zygote following the random fertilisation of haploid gametes. Understanding and prior knowledge checks are interspersed throughout the lesson as well as a series of exam-style questions which challenge the students to apply their knowledge to potentially unfamiliar situations. This lesson has been specifically planned to lead on from the previous two lessons on the cell cycle and the main stages of mitosis and constant references are made throughout to encourage students to make links and also to highlight the differences between the two types of nuclear division

This fully-resourced lesson describes the main stages of mitosis and explains the significance of this type of nuclear division in life cycles. The PowerPoint and accompanying resources have been designed to cover points 2.1.6 (c & e) of the OCR A-level Biology A specification and make direct links to the previous lesson which covered the cell cycle Depending upon the exam board taken at GCSE, the knowledge and understanding of mitosis 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 so that existing errors are addressed and key points are emphasised throughout. Their understanding of interphase is challenged at the start of the lesson to ensure that they realise that it is identical pairs of sister chromatids that enter the M phase. The main part of the lesson focuses on prophase, metaphase, anaphase and telophase and describes how the chromosomes behave in these stages. There is a focus on the centrioles and the spindle fibres that they produce which contract to drag one chromatid from each pair in opposite directions to the poles of the cell. The remainder of the lesson is 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 quiz 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.