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.
The 3 lessons contained within this lesson bundle cover the content as detailed in topic 4.5 of the Edexcel A-level Biology B specification. The lesson PowerPoints and accompanying worksheets are filled with lots of different tasks that cover the specification points shown below whilst engaging and motivating the students with exam-style questions, guided discussion periods and quiz competitions.
TOPIC 4.5: Transport of gases in blood
The structure of haemoglobin in relation to its role in the transport of respiratory gases, including the Bohr effect
Understand the oxygen dissociation curve of haemoglobin
Understand the similarities and differences between the structures and functions of haemoglobin and myoglobin
Understand the significance of the oxygen affinity of foetal haemoglobin as compared to adult haemoglobin
This lesson describes how tissue fluid is formed and reabsorbed and also describes the role of the lymphatic system in the return of fluid to the blood. The detailed PowerPoint and accompanying resources have been designed to cover points 4.6 (i & ii) of the Edexcel A-level Biology B specification and explains how a combination of the effects of hydrostatic pressure and oncotic pressure results in the formation of tissue fluid in animals.
The lesson begins with an introduction to the arteriole and venule end of a capillary as these will need to be considered as separate entities when describing the formation of tissue fluid. A quick quiz competition introduces a value for the hydrostatic pressure at the arteriole end and students are challenged to first predict some parts of the blood will move out of the capillary as a result of the push from the hydrostatic pressure and this allows oncotic pressure to be initially explored. The main part of the lesson uses a step by step guide to describe how the net movement is outwards at the arteriole end before students will use this guidance to describe what happens at the venule end. In the concluding part of the lesson, students will come to recognise oedema as a condition where tissue fluid accumulates and they again are challenged to explain how this occurs before they finally learn how the fluid is returned to the circulatory system as lymph.
This lesson describes the similarities and differences between the structure and function of haemoglobin and myoglobin. The PowerPoint and accompanying resource have been designed to cover point 4.5 (iii) of the Edexcel A-level Biology B specification
Students have already covered the structure and function of haemoglobin in topics 1.3 and 4.5, so this concise lesson has been planned to challenge that knowledge. Students are introduced to myoglobin and will learn that this is an oxygen-binding protein found in the skeletal muscle tissue. Therefore the first part of the lesson focuses on slow twitch muscle fibres, where the content of myoglobin is high, and this presents an opportunity for links to be made to respiration, mitochondria and capillaries. The main part of the lesson challenges the students to compare the two proteins on structure and function including the number of polypeptide chains and affinity for oxygen and students can assess their understanding through use of the displayed mark schemes to the series of exam-style questions.
This lesson bundle contains 17 detailed and fully-resourced lessons which cover the following specification points in topic 3 of the AQA A-level Biology specification:
Topic 3.1
The relationship between the size of an organism or structure and its surface area to volume ratio
The development of systems in larger organisms as adaptations that facilitate exchange as this ratio reduces
Topic 3.2
Adaptations of gas exchange surfaces as shown by gas exchange in single-celled organisms, insects, bony fish and the leaves of dicotyledonous plants
The gross structure of the human gas exchange system
The essential features of the alveolar epithelium as a surface over which gas exchange takes place
The mechanism of breathing to include the role of the diaphragm and the intercostal muscles
Topic 3.3
During digestion, large molecules are hydrolysed to smaller molecules
Digestion in mammals by amylases, disaccharidases, lipase, endopeptidases, exopeptidases and dipeptidases
Mechanisms for the absorption of the products of digestion by cells lining the ileum of mammals
Topic 3.4.1
The structure and role of haemoglobin in the loading, transport and unloading of oxygen
The effects of carbon dioxide concentration on the dissociation of oxyhaemoglobin
The general pattern of blood circulation in a mammal
The gross structure of the human heart
Pressure and volume changes and valve movements during the cardiac cycle
The structure of the arteries, arterioles and veins
The formation of tissue fluid and its return to the circulatory system
Topic 3.4.2
Xylem as the tissue that transports water
The cohesion-tension theory of water transport
Phloem as the tissue that transports organic substances in plants
The mass flow hypothesis for the mechanism of translocation in plants
If you would like to sample the quality of the lessons included in this bundle, then download the following lessons which have been uploaded for free
Alveolar epithelium
Absorption in the ileum
Arteries, arterioles and veins
Formation of tissue fluid
Translocation
This lesson describes the principle components of the plasma membrane, focusing on the phospholipid bilayer and membrane proteins. The detailed PowerPoint and accompanying worksheets have been designed to cover the detail in point (a) of AS unit 1, topic 3 of the WJEC A-level Biology specification and clear links are made to Singer and Nicholson’s fluid mosaic model
The fluid mosaic model is introduced at the start so that it can be referenced at appropriate points throughout the lesson. Students were introduced to phospholipids in topic 1 and so 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 lesson explains the need for specialised exchange surfaces and uses examples to describe the features of an efficient exchange surface. The PowerPoint and accompanying worksheets have been designed to cover points 3.1.1 (a & b) of the OCR A-level Biology A specification and also have been specifically planned to prepare the students for the upcoming lessons in module 3 on gas exchange and mass transport in animals.
The students are likely to have been introduced to the surface area to volume ratio at GCSE, but 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 this 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 that walks 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 a single-celled and multicellular organisms and this leads into the next part of the lesson, where the adaptations of large organisms to increase this ratio at the exchange surfaces are 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. In addition to the ratio, time is taken to discuss and describe how the maintenance of a steep concentration gradient and a thin membrane are important for the rate of diffusion and again biological examples are used in humans and other organisms to increase the understanding. Fick’s law of diffusion is also introduced as a mechanism to help the students to recall that surface area, concentration difference and thickness of membrane govern the rate of simple diffusion.
As well as making links to upcoming topics, prior knowledge checks are used to challenge the students on their knowledge of previously-covered modules which include inorganic ions, organelles, cell membrane transport and tissues.
This lesson describes the characteristic features of the Animalia, Plantae, Fungi, Protoctista and Prokaryotae kingdoms. The engaging PowerPoint and accompanying resources have been designed to cover point (d) in AS unit 2, topic 1 of the WJEC A-level Biology specification
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. An opportunity is taken at this point to check on their prior knowledge of the structure of a bacterial cell as covered in unit 1, topic 2. These prior knowledge checks are found throughout the lesson (along with current understanding checks) as students are also tested on their knowledge of the structure and function of cellulose. This 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 YOU DO THE MATH and SAY WHAT YOU SEE are used to introduce key values and words 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.
Both of the accompanying resources have been differentiated to allow students of differing abilities to access the work and this lesson has been written to tie in with the previously uploaded lesson on classification and the binomial naming system
This lesson introduces the three-domain system and describes some of the biochemical methods used in classification to overcome the problems of morphological convergence. The PowerPoint and accompanying resources have been designed to cover points [c] and [e] in AS unit 2, topic 1 of the WJEC A-level Biology specification
The lesson begins with an introduction of Carl 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. The use of DNA genetic fingerprinting is briefly introduced and this is described in greater detail in a future lesson about assessing biodiversity at a molecular level
This lesson bundle contains 5 lesson PowerPoints and together with their accompanying worksheets, they will engage and motivate the students whilst covering the following specification points in module 3.1.1 (Exchange surfaces) of the OCR A-level Biology A specification:
The need for specialised exchange surfaces
The features of an efficient exchange surface
The structures and functions of the components of the mammalian gaseous exchange system
The mechanism of ventilation in mammals
The mechanisms of ventilation and gas exchange in bony fish and insects
Found interspersed within the detailed A-level Biology content in the slides are current understanding and prior knowledge checks and these are followed by displayed mark schemes to allow students to assess their progress. There are also differentiated tasks, guided discussion periods and quiz competitions that introduce key values and terms in a fun and memorable way
If you would like to see the quality of lessons included in this bundle, then download the mammalian gaseous exchange system and ventilation and gas exchange in insects lessons as these have been uploaded for free
This lesson describes the levels of organisation, including the aggregation of cells into tissues, tissues into organs and organs into organ systems. The detailed and engaging PowerPoint and accompanying resources have been designed to cover point (d) of AS unit 1, topic 2 of the WJEC A-level Biology specification and focuses on the levels of organisation in humans and plants. Please note that the lesson does not contain prepared slides of tissue as this is covered in a later lesson.
The lesson begins by using the process of haematopoiesis from haematopoietic stem cells to demonstrate how the red blood cell and neutrophil differ significantly in structure despite arising from the same cell along the same cell lineage. A series of exam-style questions will not only challenge their knowledge of structure but also their ability to apply this knowledge to unfamiliar situations. These differences in cell structure is further exemplified by the epithelial cells of the respiratory tract and students are challenged to remember how the shape and arrangement of these cells differ in the trachea and alveoli in relation to their function. The link between specialised cells and tissues is made at this point of the lesson so students are reminded that a tissue is a group of cells that work together to perform a specific function or set of functions. Moving forwards, a quick quiz competition will challenge the students to recognise the liver, kidney, spinal cord and pancreas from a brief functional description and this leads into a series of questions that links back to topics 1 and earlier in topic 2 where proteins, organelles and carbohydrates were originally covered. These prior knowledge checks are found throughout the lesson, along with current understanding checks, and all of the mark schemes are embedded into the PowerPoint to allow students to assess their progress. In terms of organ systems, a quick task challenges them to recognise 8 of the 11 that are found in humans from descriptions and this leaves them to identify the gaseous exchange, digestive and reproductive systems as the remaining 3.
The remainder of the lesson focuses on specialised plant cells and the differing shapes and features of the palisade and spongy cells in the mesophyll layer and the guard cells are covered at length and in detail. The cells found in the xylem and phloem tissue are also discussed.
This lesson describes how the cells of multicellular organisms are organised into tissues, tissues into organs and organs into systems. The detailed and engaging PowerPoint and accompanying resources have been designed to cover point 3.13 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and focuses on the levels of organisation in humans and plants
The lesson begins by using the process of haematopoiesis from haematopoietic stem cells to demonstrate how the red blood cell and neutrophil differ significantly in structure despite arising from the same cell along the same cell lineage. A series of exam-style questions will not only challenge their knowledge of structure but also their ability to apply this knowledge to unfamiliar situations. These differences in cell structure is further exemplified by the epithelial cells of the respiratory tract and students are challenged to remember how the shape and arrangement of these cells differ in the trachea and alveoli in relation to their function. The link between specialised cells and tissues is made at this point of the lesson so students are reminded that a tissue is a group of cells that work together to perform a specific function or set of functions. Moving forwards, a quick quiz competition will challenge the students to recognise the liver, kidney, spinal cord and pancreas from a brief functional description and this leads into a series of questions that links back to topics 1 and 2 and earlier in topic 3 where blood clotting, proteins, osmosis, organelles, methods of transport, carbohydrates and enzymes were originally covered. These prior knowledge checks are found throughout the lesson, along with current understanding checks, and all of the mark schemes are embedded into the PowerPoint to allow students to assess their progress. In terms of organ systems, a quick task challenges them to recognise 8 of the 11 that are found in humans from descriptions and this leaves them to identify the gaseous exchange, digestive and reproductive systems as the remaining 3. This leads into a section about cystic fibrosis as this genetic disorder impairs the functioning of these systems.
The remainder of the lesson focuses on specialised plant cells and the differing shapes and features of the palisade and spongy cells in the mesophyll layer and the guard cells are covered at length and in detail. The cells found in the xylem and phloem tissue are also discussed.
This lesson describes the structure and functions of the organelles that are found in eukaryotic cells. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point (a) in AS Unit 1, topic 2 of the WJEC A-level Biology specification
As cells are the building blocks of living organisms, it makes sense that they would be heavily involved in all 6 modules in the OCR course and intricate planning has ensured that links to the lessons earlier in AS unit 1 are made as well as to the upcoming topics in the other units.
The lesson uses a wide range of activities, that include exam-style questions, class discussion points and quick quiz competitions, to maintain motivation and engagement whilst describing the relationship between the structure and function of the following organelles:
nucleus
nucleolus
centrioles
ribosomes
rough endoplasmic reticulum
Golgi body
lysosomes
smooth endoplasmic reticulum
mitochondria
cell surface membrane
vacuole
chloroplasts
plasmodesmata
All of the worksheets have been differentiated to support students of differing abilities whilst maintaining challenge
Due to the detail that is included in this lesson, it is estimated that it will take in excess of 3 hours of allocated A-level teaching time to go through all of the tasks
This lesson bundle contains 16 lessons which have been designed to cover the Pearson Edexcel A-level Biology A (Salters Nuffield) specification points which focus on the structure of DNA and RNA, their roles in replication and protein synthesis, and genetics and inheritance. The lesson PowerPoints are highly detailed, and along with their accompanying worksheets, they have been planned at length to contain a wide range of engaging tasks which cover the following A-level Biology content found in topics 2, 3 and 6 of the course:
2.5 (i): Know the basic structure of mononucleotides (deoxyribose or ribose linked to a phosphate and a base, including thymine, uracil, cytosine, adenine or guanine) and the structures of DNA and RNA (polynucleotides composed of mononucleotides linked through condensation reactions)
2.5 (ii): Know how complementary base pairing and the hydrogen bonding between two complementary strands are involved in the formation of the DNA double helix
2.6 (i): Understand the process of protein synthesis (transcription) including the role of RNA polymerase, translation, messenger RNA, transfer RNA, ribosomes and the role of start and stop codons
2.6 (ii): Understand the roles of the DNA template (antisense) strand in transcription, codons on messenger RNA and anticodons on transfer RNA
2.7: Understand the nature of the genetic code
2.8: Know that a gene is a sequence of bases on a DNA molecule that codes for a sequence of amino acids in a polypeptide chain
2.11 (i): Understand the process of DNA replication, including the role of DNA polymerase
2.12 (i): Understand how errors in DNA replication can give rise to mutations
2.12 (ii): Understand how cystic fibrosis results from one of a number of possible gene mutations
2.13 (i): Know the meaning of the terms: gene, allele, genotype, phenotype, recessive, dominant, incomplete dominance, homozygote and heterozygote
2.13 (ii): Understand patterns of inheritance, including the interpretation of genetic pedigree diagrams, in the context of monohybrid inheritance
2.14: Understand how the expression of a gene mutation in people with cystic fibrosis impairs the functioning of the gaseous exchange, digestive and reproductive systems
2.15 (i): Understand the uses of genetic screening, including the identification of carriers, pre-implantation genetic diagnosis (PGD) and prenatal testing, including amniocentesis and chorionic villus sampling
2.15 (ii): Understand the implications of prenatal genetic screening
3.8 (i): The loci is a location of genes on a chromosome
3.8 (ii): The linkage of genes on a chromosome and sex linkage
3.12: Understand how cells become specialised through differential gene expression, producing active mRNA leading to synthesis of proteins, which in turn control cell processes or determine cell structure in animals and plants, including the lac operon
3.14 (i): Phenotype is an interaction between genotype and the environment
3.15: Understand how some phenotypes are affected by multiple alleles for the same gene at many loci (polygenic inheritance) as well as the environment and how this can give rise to phenotypes that show continuous variation
6.4: Know how DNA can be amplified using the polymerase chain reaction (PCR)
6.10: Understand how one gene can give rise to more than one protein through posttranscriptional changes to messenger RNA (mRNA).
This lesson bundle contains 7 lessons which have been designed to cover the Pearson Edexcel A-level Biology A (Salters Nuffield) specification points which focus on the structure of eukaryotic and prokaryotic cells and the functions of their components. The lesson PowerPoints are highly detailed, and along with the accompanying worksheets, they have been planned at length to contain a wide range of engaging tasks which cover the following A-level Biology content found in topics 2, 3 and 4 of the course:
2.2 (i): Know the structure and function of cell membranes
3.1: Know that all living organisms are made of cells, sharing some common features
3.2: Know the ultrastructure of eukaryotic cells, including nucleus, nucleolus, ribosomes, rough and smooth endoplasmic reticulum, mitochondria, centrioles, lysosomes, and Golgi apparatus
3.3: Understand the role of the rough endoplasmic reticulum (rER) and the Golgi apparatus in protein transport within cells, including their role in the formation of extracellular enzymes
3.4: Know the ultrastructure of prokaryotic cells, including cell wall, capsule, plasmid, flagellum, pili, ribosomes, mesosomes and circular DNA
3.6: Understand how mammalian gametes are specialised for their functions (including the acrosome in sperm and the zona pellucida in the egg)
3.13: Understand how the cells of multicellular organisms are organised into tissues, tissues into organs and organs into systems
4.7: Know the ultrastructure of plant cells (cell walls, chloroplasts, amyloplasts, vacuole, tonoplast, plasmodesmata, pits and middle lamella) and be able to compare it with animal cells.
This lesson bundle contains 6 lessons which have been designed to cover the Edexcel International A-level Biology specification points which focus on the structure of eukaryotic and prokaryotic cells and the functions of their components. The lesson PowerPoints are highly detailed, and along with the accompanying worksheets, they have been planned at length to contain a wide range of engaging tasks which cover the following A-level Biology content found in topics 2, 3 and 4 of the course:
2.2 (i): Know the structure and function of cell membranes
3.1: Know that all living organisms are made of cells, sharing some common features
3.2: Understand how the cells of multicellular organisms are organised into tissues, tissues into organs and organs into systems
3.3: Know the ultrastructure of eukaryotic cells, including nucleus, nucleolus, ribosomes, rough and smooth endoplasmic reticulum, mitochondria, centrioles, lysosomes, and Golgi apparatus
3.4: Understand the role of the rough endoplasmic reticulum (rER) and the Golgi apparatus in protein transport within cells, including their role in the formation of extracellular enzymes
3.5: Know the ultrastructure of prokaryotic cells, including cell wall, capsule, plasmid, flagellum, pili, ribosomes, mesosomes and circular DNA
3.11: Understand how mammalian gametes are specialised for their functions (including the acrosome in sperm and the zona pellucida in the egg)
4.1 (i): Know the ultrastructure of plant cells (cell walls, chloroplasts, amyloplasts, vacuole, tonoplast, plasmodesmata, pits and middle lamella) and be able to compare it with animal cells
4.1 (ii): understand the function of the structures listed in (i)
This lesson describes the ethical and economic reasons for the maintenance of biodiversity. The engaging PowerPoint and accompanying worksheets are filled with real-life biological examples and have been designed to cover point 3.3 (ii) of the Edexcel A-level Biology B specification.
Many hours of research have gone into the planning of the lesson so that interesting examples are included to increase the relevance of the multitude of reasons to maintain biodiversity. These include the gray wolves and beavers of Yellowstone National Park and the Za boabab in the Madagascar rainforests as examples of keystone species. Students will learn that these species have a disproportionate effect on their environment relative to their abundance and exam-style questions and guided discussion periods are used to challenge them to explain their effect on other species in the habitat. The latest A-level Biology exams have a heavy mathematical content and this is reflected in this lesson as students are challenged to complete a range of calculations to manipulate data to support their biological-based answers. All of the exam questions that are included throughout the lesson have mark schemes embedded into the PowerPoint to allow the students to assess their progress. Moving fowards, the economic ans aesthetic reasons to maintain biodiversity are considered, and there is a focus on the soil depletion that occurs when a continuous monoculture is used. The 1 Billion tree scheme that began in New Zealand in 2018 is introduced and the reasons that some groups of people are objecting to what they consider to be a pine monoculture are discussed. Students will recognise that the clear felling of the trees dramatically changes the landscape and that the increased runoff that results can have catastrophic affects for both aquatic life and for humans with floods.
A number of quiz competitions are included in the lesson to introduce key terms in a fun and memorable way and some of the worksheets have been differentiated to allow students of differing abilities to access the work
This lesson describes a range of methods that can be used to assess the distribution and abundance of organisms in a local area. The PowerPoint and accompanying worksheets have been designed to cover points [c] and [d] of topic 18.1 of the CIE A-level Biology specification and describe the use of frame quadrats, line and belt transects, and the mark-release-recapture method.
Due to the substantial mathematical content of the A-level Biology exams, as well as descriptions of the different methods, there is a focus on the range of calculations that are used to estimate the population of either sessile or motile species. As shown by the image, step by step guides are used to walk the students through the key stages in these calculations before exam-style questions challenge them to apply their understanding and mark schemes are included in the lesson to allow them to immediately assess their progress. The precautions and assumptions associated with the mark-release-recapture method are discussed and links are made to stabilising selection as covered in topic 17 when considering how the number of species have changed over time.
Each of the 6 specification points in topic 8.2 of the Edexcel A-level Biology B specification are covered by the 6 lessons included in this bundle:
(i) Understanding of the key genetic terms
(ii) Be able to construct genetic crosses and pedigree diagrams
(iii) Understand the inheritance of two non-interacting unlinked genes
(iv) Understand that autosomal linkage results from the presence of alleles on the same chromosome
(v) Understand sex linkage on the X chromosome
(vi) Be able to use the chi squared test
The lessons contain step by step guides that walk students through the key details of this topic, such as the construction of genetic crosses or the calculation of the chi squared value. There are also lots of exam-style questions to challenge the students to apply their understanding and the mark schemes that are embedded in the PowerPoints will allow them to assess their progress.
The sex linkage lesson has been uploaded for free if you would like to sample the quality of lessons in this bundle.
This lesson discusses how biodiversity may be considered at different levels and describes how to calculate Simpson’s Index of diversity. The PowerPoint and accompanying worksheets have primarily been designed to cover points 4.2.1 (a, c and d) of the OCR A-level Biology A specification but also make links to the upcoming topics of classification, natural selection and adaptations
A quiz competition called BIOLOGICAL TERMINOLOGY SNAP runs over the course of the lesson and this will engage the students whilst challenging them to recognise species, population, biodiversity, community and natural selection from their respective definitions. Once biodiversity as the variety of living organisms in a habitat is revealed, the students will learn that this can relate to a range of habitats, from those in the local area to the Earth. Moving forwards, the students will begin to understand that biodiversity can be considered at a range of levels which include within a habitat, within a species and within different habitats so that they can be compared. Species richness as a measure of the number of different species in a community is met and a biological example in the rainforests of Madagascar is used to increase its relevance. However, students will also be introduced to species evenness and will learn that in order for a habitat to be deemed to be biodiverse, it must be both species rich and even. The students are introduced to an unfamiliar formula that calculates the heterozygosity index and are challenged to apply their knowledge to this situation, as well as linking a low H value to natural selection. The rest of the lesson focuses on the calculation of Simpson’s Index of diversity and a 4-step guide is used to walk students through each part of the calculation. This is done in combination with a worked example to allow students to visualise how the formula should be applied to actual figures. Using the method, they will then calculate a value of D for a comparable habitat to allow the two values to be considered and the significance of a higher value is explained. All of the exam-style questions have mark schemes embedded in the PowerPoint to allow students to continuously assess their progress and understanding.
This lesson describes self and non-self antigens and how a failure to distinguish between the two is the mechanism of autoimmune diseases. The PowerPoint and accompanying worksheets have been primarily designed to cover points 11.1 (d & f) of the CIE A-level Biology specification and describe examples of these diseases including myasthenia gravis, but this lesson can also be used to revise the content of the earlier topics as well as the previous lessons in topic 10 & 11 through the range of activities that are included
The first part of the lesson focuses on the antigens and explains how the failure of the immune system cells to recognise these molecules on the outside of a cell or organism elicits an immune response. Moving forwards, the students are challenged to recognise diseases from descriptions and then to use the first letters of their names to form the term, autoimmune. In doing so, the students will discover that rheumatoid arthritis, ulcerative colitis, type I diabetes mellitus, multiple sclerosis and myasthenia gravis are all examples of autoimmune diseases. The next part of the lesson focuses on the mechanism of these diseases where the immune system cells do not recognise the antigens (self-antigens) on the outside of the healthy cells, and therefore treats them as foreign antigens, resulting in the production of autoantibodies against proteins on these healthy cells and tissues. Key details of the autoimmune diseases stated above and lupus are described and links to previously covered topics as well as to future topics such as the pancreas and nervous system are made. The students will be challenged by the numerous exam-style questions, all of which have mark schemes embedded into the PowerPoint to allow for immediate assessment of progress.
