A Science teacher by trade, I've also been known to be found teaching Maths and PE! However, strange as it may seem, my real love is designing resources that can be used by other teachers to maximise the experience of the students. I am constantly thinking of new ways to engage a student with a topic and try to implement that in the design of the lessons.
A Science teacher by trade, I've also been known to be found teaching Maths and PE! However, strange as it may seem, my real love is designing resources that can be used by other teachers to maximise the experience of the students. I am constantly thinking of new ways to engage a student with a topic and try to implement that in the design of the lessons.
This fully-resourced lesson describes how cells become specialised through differential gene expression. The PowerPoint and accompanying resources have been designed to cover the details of point 3.19 of the Edexcel International A-level Biology specification.
This is one of the more difficult concepts in this A-level course and therefore key points are reiterated throughout this lesson to increase the likelihood of student understanding and to support them when trying to make links to actual biological examples in living organisms. There is a clear connection to transcription and translation as covered in topic 2, so the lesson begins by reminding students that in addition to the structural gene in a transcription unit, there is the promotor region where RNA polymerase binds. Students are introduced to the idea of transcription factors and will understand how these molecules can activate or repress transcription by enabling or preventing the binding of the enzyme. At this point, students are challenged on their current understanding with a series of questions about DELLA proteins so they can see how these molecules prevent the binding of RNA polymerase. The final section of the lesson looks at one further example with oestrogen and the ER receptor and explains how the binding of this chemical results in the release of the inhibitor and the production of active mRNA.
This detailed and fully-resourced lesson describes the relationship between the structure and function of glycogen and amylose and amylopectin as components of starch. The engaging PowerPoint and accompanying resources have been designed to cover the fourth part of points 1.2 & 1.4 of the Edexcel International A-level Biology specification and links are continuously made to the previous lessons in this topic where the monosaccharides and disaccharides were introduced.
The lesson begins with the CARBOHYDRATE WALL where students have to use their prior knowledge to collect the 9 carbohydrates on show into 3 groups. This results in glycogen, starch and cellulose being grouped together as polysaccharides and the structure and roles of the first two are covered over the course of the lesson. Cellulose is covered in a lesson in topic 4. Students will learn how key structural features like the 1 - 4 and 1 - 6 glycosidic bonds and the hydrogen bonds dictate whether the polysaccharide chain is branched or unbranched and also allows for spiralling. Following the description of the structure of glycogen, students are challenged to design an exam question in the form of a comparison table so that it can be completed as the lesson progresses and they learn more about starch. This includes a split in the starch section of the table so that the differing structures and properties of amylose and amylopectin can be considered. The importance of the compact structure for storage is discussed as well as the branched chains of amylopectin acting as quick source of energy when it is needed. The lesson concludes with a question and answer section that guides the students when answering a question about the importance of the lower solubility of the polysaccharides when compared to the monosaccharides.
This clear and concise lesson describes the meaning of a gene locus and explains how the inheritance of two or more genes that have loci on the same chromosome demonstrates linkage. The engaging PowerPoint and associated resource have been designed to cover points 3.9 (i) and (ii) of the Edexcel International A-level Biology specification and makes clear links to the upcoming topic of meiosis when describing the effect of crossing over on this linkage
This is a topic which can cause confusion for students so time was taken in the design to split the concept into small chunks. There is a clear focus on how the number of original phenotypes and recombinants can be used to determine linkage and suggest how the loci of the two genes compare. Important links to other topics such as crossing over in meiosis are made to enable students to understand how the random formation of the chiasma determines whether new phenotypes will be seen in the offspring or not. Linkage is an important cause of variation and the difference between observed and expected results and this is emphasised on a number of occasions. The main task of the lesson acts as an understanding check where students are challenged to analyse a set of results involving the inheritance of the ABO blood group gene and the nail-patella syndrome gene to determine whether they have loci on the same chromosome and if so, how close their loci would appear to be.
This fully-resourced lesson describes the relationship between the structure of monosaccharides and their roles in living organisms. The detailed and engaging PowerPoint and accompanying resources have been designed to cover the second part of points 1.12 & 1.13 of the Pearson Edexcel A-level Biology A specification and looks at alpha-glucose, galactose, fructose, deoxyribose and ribose.
The lesson begins with a made-up round of the quiz show POINTLESS, where students have to try to identify four answers to do with carbohydrates. In doing so, they will learn or recall that these molecules are made from carbon, hydrogen and oxygen, that they are a source of energy which can sometimes be rightly or wrongly associated with obesity and that the names of the three main groups is derived from the Greek word sakkharon. Using the molecular formula of glucose as a guide, students will be given the general formula for the monosaccharides and will learn that deoxyribose is an exception to the rule that the number of carbon and oxygen atoms are equal. Moving forwards, students have to study the displayed formula of glucose for two minutes without being able to note anything down before they are challenged to recreate what they saw in a test of their observational skills. At this point of the lesson, the idea of numbering the carbons is introduced so that the different glycosidic bonds can be understood in an upcoming lesson as well as the recognition of the different isomers of glucose. The difference between alpha and beta-glucose is provided but students do not need to consider the beta form until topic 4. The remainder of the lesson focuses on the roles of the monosaccharides and the final task involves a series of application questions where the students are challenged to suggest why ribose could be considered important for active transport and muscle contraction
This fully-resourced lesson uses the lac operon as an example to describe how gene expression is regulated and controls cell processes and structures. The detailed PowerPoint and accompanying resources have been designed to cover the details of specification point 3.12 of the Pearson Edexcel A-level Biology A course.
This is one of the more difficult concepts in this A-level course and therefore key points are reiterated throughout this lesson to increase the likelihood of student understanding and to support them when trying to make links to actual biological examples in living organisms. There is a clear connection to transcription and translation as covered in topic 2, so the lesson begins by reminding students that in addition to the structural gene in a transcription unit, there is the promotor region where RNA polymerase binds. Students are introduced to the idea of transcription factors and will understand how these molecules can activate or repress transcription by enabling or preventing the binding of the enzyme. At this point, students are challenged on their current understanding with a series of questions about DELLA proteins so they can see how these molecules prevent the binding of RNA polymerase. The main section of the lesson focuses on the lac operon. Students will be able to visualise the different structures that are found in this unit of DNA and time is taken to go through the individual functions. A step by step guide is used to walk students through the sequence of events that occur when lactose is absent and when it is present before they are challenged to apply their understanding to an exam question. The final section of the lesson looks at one further example with oestrogen and the ER receptor.
This fully-resourced lesson describes how it’s possible for 1 gene to give rise to multiple proteins as a result of post-transcriptional changes to mRNA. The detailed PowerPoint and accompanying resources have been primarily designed to cover point 6.10 of the Pearson Edexcel A-level Biology A specification but also checks on the students knowledge and understanding of the lac operon as covered in topic 3.
The lesson begins with a knowledge recall as the students have to recognise the definition of a gene as a sequence of bases on a DNA molecule that codes for a sequence of amino acids in a polypeptide chain. This description was introduced in topic 2 and the aim of the start of the lesson is to introduce the fact that despite this definition, most of the nuclear DNA in eukaryotes doesn’t actually code for proteins. A quick quiz competition is then used to introduce exons as the coding regions within a gene before students are challenged to predict the name of the non-coding regions and then to suggest a function for these introns. At this point, the students will complete a task that acts as a prior knowledge check where they have to identify the 6 errors in the descriptive passage about the lac operon and its role in the regulation of gene expression in prokaryotes. Moving forwards, pre-mRNA as a primary transcript is introduced and students will learn that this isn’t the mature strand that moves off to the ribosome for translation. Instead, a process called splicing takes place where the introns are removed and the remaining exons are joined together. Another quick quiz round leads to an answer of 20000 and students will learn that this is the number of protein-coding genes in the human genome. Importantly, the students are then told that the number of proteins that are synthesised is much higher than this value and a class discussion period encourages them to come up with biological suggestions for this discrepancy between the two numbers. The lesson concludes with a series of understanding and application questions where students will learn that alternative splicing enables a gene to produce more than a single protein and that this natural phenomenon greatly increases biodiversity.
This detailed and fully-resourced lesson describes the structure and properties of the cell membrane, focusing on the phospholipid bilayer and membrane proteins. The PowerPoint and accompanying worksheets have been designed to cover point 2.2 of the Pearson Edexcel A-level Biology A specification and makes links to the fluid mosaic model which is covered in greater detail in the next lesson.
Students were introduced to triglycerides in topic 1 and the start of this lesson challenges them to recall the structure of this lipid to identify the shared features of a phospholipid. This introduces the structure of this macromolecule as a glycerol molecule, two fatty acids and a phosphate group. Time is taken to look at the differing properties of the phosphate group and the fatty acid tails so that students become comfortable with the terms hydrophobic and hydrophilic. At this point, the class is given an opportunity to discuss how the phospholipids are arranged when both the inside and outside of the cell contains an aqueous solution and the phospholipid bilayer as the fabric of the membrane is subsequently met. 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 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. It is at this point of the lesson that students will meet the fluid mosaic model and will begin to understand how this describes the dynamic nature of the membrane as well as explaining the interaction with the environment. 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 detailed lesson describes how the crossing over of alleles and the independent assortment in meiosis contribute to genetic variation. The PowerPoint and accompanying resource have been designed to cover specification point 3.10 of the Edexcel International A-level Biology specification and includes describes how the fertilisation of the haploid gametes that were formed by meiosis increases variation further.
In order to understand how the events of meiosis like crossing over and random 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 segregation of chromosomes and chromatids during anaphase I and II results in genetically different gametes. 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 questions which challenge the students to apply their knowledge to potentially unfamiliar situations.
This fully-resourced lesson describes the role of mitosis and the cell cycle in producing identical cells for growth and asexual reproduction. The detailed PowerPoint and accompanying differentiated resources have been designed to cover point 3.10 of the Pearson Edexcel A-level Biology A specification
In the previous lesson covering meiosis (3.9), students were introduced to the different phases and structures involved in the cycle so this lesson builds on that by providing greater detail of the key events in each phase. Beginning with a focus on interphase, the importance of DNA replication is explained so that students can initially recognise that there are pairs of identical sister chromatids and then can understand how they are separated later in the cycle. A quiz competition has been written into the lesson and this runs throughout, challenging the students to identify the quantity of DNA in the cell (in terms of n) at different points of the cycle. The main part of the lesson focuses on prophase, metaphase, anaphase and telophase and describes how the chromosomes behave in these stages. Students will understand how the cytoplasmic division that occurs in cytokinesis results in the production of genetically identical daughter cells. This leads into a series of understanding and application questions where students have to identify the various roles of mitosis in living organisms as well as tackling a Maths in a Biology context question. The lesson concludes with a final round of MITOSIS SNAP where they only shout out this word when a match is seen between the name of a phase, an event and a picture.
This 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 lesson describes the properties of gas exchange surfaces and shows how Fick’s law of diffusion is dependent on these properties. The PowerPoint and accompanying worksheets have been designed to cover points 2.1 (i & ii) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and there is a particular focus on the relationship between the size of an organism or structure and its surface to volume ratio.
Adolf Fick is briefly introduced at the start of the lesson and the students will learn that his law of diffusion governs the diffusion of a gas across a membrane and is dependent on three properties. The students are likely to know that surface area is one of these properties but although they may have been introduced to the surface area to volume ratio at GCSE, their understanding of its relevance tends to be mixed. Therefore, real life examples are included throughout the lesson that emphasise the importance of this ratio in order to increase the relevance. A lot of students worry about the maths calculations that are associated with this topic so a step by step guide is included at the start of the lesson to walk them through the calculation of the surface area, the volume and then the ratio. Through worked examples and understanding checks, SA/V ratios are calculated for cubes of increasing side length and living organisms of different size. These comparative values will enable the students to conclude that the larger the organism or structure, the lower the surface area to volume ratio. A differentiated task is then used to challenge the students to explain the relationship between the ratio and the metabolic demands of an organism and this leads into the next part of the lesson, where the adaptations of a human to increase the ratio at the gas exchange surface is covered. The students will calculate the SA/V ratio of a human alveolus (using the surface area and volume formulae for a sphere) and will see the significant increase that results from the folding of the membranes. The remainder of the lesson introduces concentration difference and thickness of membrane as the other two properties in Fick’s law of diffusion and students are reminded that the maintenance of a steep concentration gradient and a reduction in the diffusion distance are critical for this transport mechanism.
This lesson has been specifically planned to prepare students for the next lesson which describes how the structure of the mammalian lung is adapted for rapid gas exchange (specification point 2.1 [iii])
This engaging and fully-resourced lesson explores how genetic drift can arise after a population bottleneck or as a result of the Founder effect. The detailed PowerPoint and accompanying resources have been designed to cover points 8.3 (ii) & (iii) of the Edexcel A-level Biology B specification
A wide range of examples are used to show the students how a population that descends from a small number of parents will have a reduction in genetic variation and a change in the frequency of existing alleles. Students are encouraged to discuss new information to consider key points and understanding checks in a range of forms are used to enable them to check their progress and address any misconceptions. Students are provided with three articles on Huntington’s disease in South Africa, the Caribbean lizards and the plains bison to understand how either a sharp reduction in numbers of a new population beginning from a handful of individuals results in a small gene pool. Links to related topics are made throughout the lesson to ensure that a deep understanding is gained.
This lesson describes how molecular evidence can be used to reveal similarities between closely-related organisms. The PowerPoint and accompanying resources have been primarily designed to cover point 17.3 (b) of the CIE A-level Biology specification and focus on the comparison of protein structure and mitochondrial DNA but can also be used as a revision of related topics that include protein synthesis and gene mutations.
The lesson begins with the introduction of convergent evolution, a process where organisms independently evolve to have similar features due to theeir habitation of similar environments. This allows the importance of molecular evidence to be considered to ensure that organisms which are closely related (in terms of evolution) are recognised. The comparison of the primary structure of a protein involved in respiration (cytochrome c) is used to demonstrate how protein sequence data can be useful. At this point, a series of exam-style questions are used to challenge the students on their knowledge of protein synthesis and gene mutations from topics 6 and 16. The remainder of the lesson considers the use of mitochondrial DNA and a study of the mtDNA genomes of 51 gibbons demonstrates how this can provide evidence of relationships, even in organisms that show high taxonomic diversity like these lesser apes.
This detailed lesson outlines the characteristics features of the kingdoms Protoctista, Fungi, Plantae and Animalia. The engaging PowerPoint and accompanying resources have been designed to cover point 18.2 [c] of the CIE International A-level Biology specification which states that students should be able to describe the features of these four eukaryotic kingdoms.
This lesson begins with a knowledge recall as students have to recognise that prior to 1990, kingdom was the highest taxa in the classification hierarchy. Moving forwards, they will recall the names of the five kingdoms and immediately be challenged to split them so that the prokaryotae kingdom is left on its own. The features of this kingdom are given so that the lesson can focus on the four eukaryotic kingdoms. Students are constantly challenged on their understanding of the current topic as well as that of earlier topics, as demonstrated by a differentiated task about the structure and function of cellulose which was covered in topic 2. This task is found in the section of the lesson where the main constituent of the wall can be used to distinguish between plantae, fungi and prokaryotae. Quick quiz competitions, such as SAY WHAT YOU SEE are used to introduce key terms in a fun and memorable way. The final part of the lesson looks at the protoctista kingdom and students will come to understand how these organisms tend to share a lot of animal or plant-like features.
This fully-resourced lesson describes the ultrastructure of plant cells and includes the cell walls, chloroplasts, amyloplasts, vacuole, tonoplast, plasmodesmata, pits and middle lamella. The detailed PowerPoint and accompanying resources have been designed to cover point 4.7 of the Pearson Edexcel A-level Biology specification and also compares this structure against animal cells that was covered at the beginning of topic 3.
The lesson begins with a task called REVERSE GUESS WHO which will challenge the students to recognise a particular organelle 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 next part of the lesson focuses on the relationship between the structure and function of the vacuole, chloroplast, plasmodesmata 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. Students will learn that chloroplasts and amyloplasts can contain stores of starch so an opportunity is taken to challenge them on their knowledge of this polysaccharide as it was covered in topic 1. The final task challenges them to recognise descriptions of the cell wall, chloroplast, amyloplasts, vacuole, tonoplast and plasmodesmata which will leave 2 remaining which describe the pits and middle lamella.
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 explains how to calculate the net primary productivity by subtracting a plant’s respiratory losses from the gross primary productivity. The PowerPoint and accompanying resources have been designed to cover points 5.9 (i) and (ii) of the Edexcel International A-level Biology specification.
Due to the fact that the productivity of plants is dependent on photosynthesis, a series of exam-style questions have been written into the lesson which challenge the students to explain how the structure of the leaf as well as the light-dependent and light-independent reactions are linked to GPP. All of the exam questions have displayed mark schemes which are included in the PowerPoint to allow students to immediately assess their understanding. A number of quick quiz competitions as well as guided discussion points are used to introduce the formulae to calculate NPP and N and to recognise the meaning of the components. Once again, this is immediately followed by the opportunity to apply their understanding to selected questions
This lesson describes the similarities and differences between the xylem and phloem vessels and the sclerenchyma fibres. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 4.11 of the Pearson Edexcel A-level Biology A specification which states that students should be able to compare these tissues in terms of structure, position in the stem and function.
The lessons begins by challenging the students to identify the substances that a plant needs for the cellular reactions, where they are absorbed and where these reactions occur in a plant. The aim of this task is to get the students to recognise that water and mineral ions are absorbed in the roots and needed in the leaves whilst the products of photosynthesis are in the leaves and need to be used all over the plant. Students will be reminded that the xylem and phloem are part of the vascular system responsible for transporting these substances and then the rest of the lesson focuses on linking structure to function. A range of tasks which include discussion points, exam-style questions and quick quiz rounds are used to describe how lignification results in the xylem as a hollow tube of xylem cells to allow water to move as a complete column. They will also learn that the narrow diameter of this vessel allows capillary action to move water molecules up the sides of the vessel. The same process is used to enable students to understand how the structures of the companion cells allows assimilates to be loaded before being moved to the sieve tube elements through the plasmodesmata.
The final part of the lesson introduces the sclerenchyma tissue as part of the vascular bundle and along with the structure and function, the students will observe where this tissue is found in the stem in comparison to the xylem and phloem.
It is estimated that it will take in excess of 2 hours of A-level teaching time to cover the detail which has been written into this lesson
This fully-resourced lesson explores how reproductive isolation can potentially lead to the formation of a new species by speciation . The engaging PowerPoint and accompanying resources have been designed to cover point 5.19 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification which states that students should understand how isolation reduces gene flow between populations which can lead to allopatric or sympatric speciation.
The lesson begins by using the example of a hinny, which is the hybrid offspring of a horse and a donkey, to challenge students to recall the biological classification of a species. Moving forwards, students are introduced to the idea of speciation and the key components of this process, such as isolation and selection pressures, are covered and discussed in detail. Understanding and prior knowledge checks are included throughout the lesson to allow the students to not only assess their progress against the current topic but also to make links to earlier topics in the specification. Time is taken to look at the details of allopatric speciation and how the different mutations that arise in the isolated populations and genetic drift will lead to genetic changes. The example of allopatric speciation in wrasse fish because of the isthmus of Panama is used to allow the students to visualise this process. The final part of the lesson considers sympatric speciation and again a wide variety of tasks are used to enable a deep understanding to be developed.
