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 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 how Fick’s law of diffusion is governed by the three main properties of gas exchange surfaces in living organisms. The PowerPoint and accompanying worksheets have been designed to cover points 2.1 (i & ii) of the Edexcel International A-level Biology 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 iGCSE, 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 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 lesson describes the relationship between the size of an organism or structure and its surface to volume ratio. The PowerPoint and accompanying worksheets have been designed to cover point 3.1 of the AQA A-level Biology specification and also have been specifically planned to prepare the students for the upcoming lessons in topic 3 on gas exchange and absorption in the ileum.
The students are likely to have been introduced to the 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 the surface area to volume 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 an organism and this leads into the next part of the lesson, where the adaptations of larger organisms to increase the ratio at their exchange surfaces 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. This is further demonstrated by the villi and the microvilli on the enterocytes that form the epithelial lining of these folds in the ileum. The final part of the lesson introduces Fick’s law of diffusion so that students are reminded that the steepness of a concentration gradient and the thickness of a membrane also affect the rate of diffusion.
This lesson describes the relationship between the specialised features of the mammalian egg and sperm and their functions. The PowerPoint and accompanying resources have been designed to cover point 3.11 of the Edexcel International A-level Biology specification and includes a focus on the acrosome in the head of the sperm and the zona pellucida in the egg
The lessons at the start of topic 3 (Cell structure, Reproduction and Development) described the ultrastructure of eukaryotic cells, so this knowledge is referenced throughout the lesson and the students are challenged on their recall and understanding through a range of prior knowledge checks. For example, two of the exam-style questions that are included in the resources challenge the students to explain why a sperm cell is classified as an eukaryotic cell and to recognise the centrioles and the nucleus from structural descriptions. Along with the mitochondria, time is then taken to discuss and to describe the role of these organelles in relation to the function of the sperm cell. When considering the fusion of the haploid nuclei to form a diploid nucleus in the nucleus, links are made to the upcoming topic of mitosis and the significance of this form of nuclear division. The importance of the enzymes that are found inside the acrosome is emphasised and this leads into the second half of the lesson where the layers surrounding the plasma membrane of the egg cell (corona radiata and zona pellucida) are examined
The final part of this lesson has been specifically planned to prepare the students for the next lesson in topic 3, where the acrosome reaction, cortical reaction and the fusion of nuclei that are involved in fertilisation are described
This lesson describes the relationship between the specialised structural features of the mammalian gametes and their functions. The PowerPoint and accompanying resources have been designed to cover point 3.6 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and includes descriptions of the acrosome in the head of the sperm and the zona pellucida in the egg
The lessons at the start of topic 3 (Voice of the genome) described the ultrastructure of eukaryotic cells, so this knowledge is referenced throughout the lesson and the students are challenged on their recall and understanding through a range of prior knowledge checks. For example, two of the exam-style questions that are included in the resources challenge the students to explain why a sperm cell is classified as an eukaryotic cell and to recognise the centrioles and the nucleus from structural descriptions. Along with the mitochondria, time is then taken to discuss and to describe the role of these organelles in relation to the function of the sperm cell. When considering the role of the haploid nucleus, links are made to the upcoming topic of meiosis and the events that contribute to variation. The importance of the enzymes that are found inside the acrosome is emphasised and this leads into the second half of the lesson where the layers surrouding the plasma membrane of the egg cell (corona radiata and zona pellucida) are examined
The final part of this lesson has been specifically planned to prepare the students for the next lesson in topic 3, where the acrosome reaction, cortical reaction and the fusion of nuclei that are involved in fertilisation are described
This lesson describes the transport mechanism of osmosis as the movement of water molecules from a high water potential to a lower water potential. The PowerPoint and accompanying resources are part of the second lesson in a series of 4 lessons which have been designed to cover point [c] as detailed in AS unit 1, topic 3 of the WJEC A-level Biology specification and also describes how cells are affected by this movement of water
It’s likely that students will have used the term concentration in their osmosis definitions at GCSE, so the aim of the starter task is to introduce water potential to allow students to begin to recognise osmosis as the movement of water molecules from a high water potential to a lower potential, with the water potential gradient. Time is taken to describe the finer details of water potential to enable students to understand that 0 is the highest value (pure water) and that this becomes negative once solutes are dissolved. Exam-style questions are used throughout the lesson to check on current understanding as well as prior knowledge checks which make links to previously covered topics such as the lipid bilayer of the cell membrane. The remainder of the lesson focuses on the movement of water when animal and plant cells are suspended in hypotonic, hypertonic or isotonic solutions and the final appearance of these cells is described, including any issues this may cause.
This lesson describes how molecules move across the cell membrane by the transport mechanisms of (simple) diffusion and facilitated diffusion. The PowerPoint and accompanying resources are the first lesson in a series of 4 lessons which have been designed to cover the detail of point [c] in unit 1, topic 3 of the WJEC A-level Biology specification and the factors that increase the rate of diffusion are covered along with the limitations imposed by the phospholipid bilayer and the role of channel and carrier proteins.
The structure and properties of cell membranes were described in the lesson covering point (a) of this topic, so this lesson has been written to include continual references to the content of that lesson. This enables links to be made between the movement across a cell membrane with the concentration gradient, the parts of the membrane that are involved and any features that may increase the rate at which the molecules move. A series of questions about the alveoli are used to demonstrate how a large surface area, a short diffusion distance and the maintenance of a steep concentration gradient will increase the rate of simple diffusion. One of two quick quiz rounds is then used to introduce temperature and size of molecule as two further factors that can affect simple diffusion. The remainder of the lesson focuses on facilitated diffusion and describes how transmembrane proteins are needed to move small, polar or large molecules from a high concentration to a lower concentration across a partially permeable membrane
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 describes the mechanisms by which the products of digestion are absorbed by the cells lining the ileum. The PowerPoint and accompanying resources are part of the second lesson in a series of 2 which cover the content detailed in point 3.3 of the AQA A-level Biology specification and focuses on the relationship between the structure and function of this section of the small intestine.
This lesson has been specifically planned to challenge the students on their understanding of digestion in the mouth, the stomach and the duodenum as covered in the previous lesson and to build on this knowledge to allow them to recognise how the products of digestion are then absorbed in the ileum. Time is taken to describe how the folds of the ileum known as villi and the multiple microvilli found on each villus act to significantly increase the surface area for absorption and the adsorption of enzymes. The mechanism of co-transport was described in topic 2.3 so a series of exam-style questions are then used to check that the students can explain how these proteins are used to absorb monosaccharides and amino acids from the ileum. The remainder of the lesson explains why the formation of micelles is critical for the absorption of monoglycerides and fatty acids
Photosynthesis and respiration are two of the most commonly assessed topics in A-level exams but these questions are sometimes poorly answered by students due to a lack of understanding or an inability to apply their knowledge. With this in mind, these 8 lessons have been intricately planned to contain a wide range of activities that will engage and motivate the students whilst covering the key detail to try to deepen their understanding and includes exam-style questions so they are fully prepared for these assessments.
The following specification points in topics 5 and 7 of the Edexcel International A-level Biology specification are covered by these lessons:
Understand the overall reaction of photosynthesis
Understand the light-dependent reactions of photosynthesis including the role of these electrons in generating ATP, reducing NADP in photophosphorylation and producing oxygen through photolysis of water
Understand the light-independent reactions as reduction of carbon dioxide using the products of the light-dependent reactions
Know that the products are simple sugars that are used by plants, animals and other organisms in respiration and the synthesis of new biological molecules
Understand the structure of chloroplasts in relation to their role in photosynthesis
Understand the overall reaction of aerobic respiration
Understand that respiration is a many-stepped process with each step controlled and catalysed by a specific intracellular enzyme
Understand the roles of glycolysis in aerobic and anaerobic respiration
Understand the role of the link reaction and the Krebs cycle in the complete oxidation of glucose and formation of carbon dioxide, ATP, reduced NAD and reduced FAD
Understand how ATP is synthesised by oxidative phosphorylation
If you would like to sample the quality of the lessons in this bundle then download the products of photosynthesis lesson as this has been shared for free
Photosynthesis and respiration are two of the most commonly assessed topics in A-level exams but are often poorly understood by students. These 9 lessons have been intricately planned to contain a wide range of activities that will engage and motivate the students whilst covering the key detail to try to deepen their understanding and includes exam-style questions so they are fully prepared for these assessments.
The following specification points in topics 5 and 7 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification are covered by these lessons:
Understand the overall reaction of photosynthesis
Understand the light-dependent reactions of photosynthesis including the role of these electrons in generating ATP, reducing NADP in photophosphorylation and producing oxygen through photolysis of water
Understand the light-independent reactions as reduction of carbon dioxide using the products of the light-dependent reactions
Know that the products are simple sugars that are used by plants, animals and other organisms in respiration and the synthesis of new biological molecules
Understand the structure of chloroplasts in relation to their role in photosynthesis
Understand the overall reaction of aerobic respiration
Understand that respiration is a many-stepped process with each step controlled and catalysed by a specific intracellular enzyme
Understand the roles of glycolysis in aerobic and anaerobic respiration
Understand the role of the link reaction and the Krebs cycle in the complete oxidation of glucose and formation of carbon dioxide, ATP, reduced NAD and reduced FAD
Understand how ATP is synthesised by oxidative phosphorylation
Understand what happens to lactate after a period of anaerobic respiration in animals
If you would like to sample the quality of the lessons in this bundle then download the light independent reactions, the link reaction and Krebs cycle and the fate of lactate lessons as these have been shared for free
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 how large molecules are hydrolysed to smaller molecules by the enzymes produced by the digestive system in mammals. The detailed PowerPoint and accompanying worksheets are part of the 1st lesson in a series of 2 which have been designed to cover the content of point 3.3 of the AQA A-level Biology specification and this lesson includes descriptions of the action of amylase, disaccharidases, lipase, endopeptidases, exopeptidases and dipeptidases.
The lesson has been designed to walk the students through the functions of the digestive system at each point of the digestive tract up until the duodenum and focuses on the action of the enzymes produced in the mouth, stomach and small intestine and by the accessory organs of the system. Time is taken to describe and explain key details, such as the fact that endopeptidases cleave peptide bonds within the molecules, meaning that they cannot break down proteins into monomers. The lesson is filled with exam-style questions which will develop their understanding of the current topic as well as checking on their knowledge of related topics which have been previously-covered such as the structure of the biological molecules and qualitative tests. In addition to the detailed content and regular questioning, the lesson PowerPoint contains guided discussion periods and two quick quiz competitions which introduce a key term and a key value in a fun and memorable way
This lesson has been specifically planned to prepare the students for the very next lesson where the mechanisms for the absorption of the products of digestion are described.
“Overall, at least 10% of the marks in assessments for biology will require the use of mathematical skills”
This sentence is taken directly from the AQA A-level Biology specification and clearly shows that being able to apply these skills in the context of biology will have a significant impact on a student’s chances of success.
This bundle has been created to cover as much of those mathematical skills as possible and the following specification points are covered by these 6 lessons:
Represent phenotypic ratios (monohybird and dihybrid crosses)
Use and manipulate the magnification formula
Use the chi-squared test to test the significance of the difference between observed and expected results
Use the Hardy-Weinberg principle to calculate changes in allele frequency
Calculate an index of diversity for a habitat
A revision lesson is also included in this bundle which acts as a fun and engaging revision of the range of calculations
Without doubt, the CIE A-level Biology specification contains a lot of maths calculations and every year, there are a large number of exam questions that require the application of a range of mathematical skills. Therefore, a clear understanding of how and when to apply these skills is closely related to success on this course and the following calculations are covered by the 7 lessons that are included in this bundle:
Using the eyepiece graticule and stage micrometer to measure cells and be familiar with units
Calculating actual sizes of specimens from drawings, photomicrographs and electron micrographs
Using the chi-squared test to determine significance between the observed and expected results of a genetic cross
Use the t-test to compare the variation of two populations
Using the Hardy Weinberg principle to calculate allele, genotype and phenotype frequencies in populations
Use Spearman’s rank correlation to analyse relationships between the distribution and abundance of species and abiotic or biotic factors
Using Simpson’s index of diversity to calculate the biodiversity of a habitat
All of the lessons contain step by step guides that walk the students through the application of the formulae and there are lots of worked examples and exam-style questions for the students to use to assess understanding
The topics of selection, evolution, biodiversity, classification and conservation are key concepts in Biology, that are regularly assessed in the exams, but are not always that well understood by the students. With this at the forefront of the lesson design, these 16 lesson PowerPoints and their accompanying resources have been intricately planned to cover the detailed content of topics 17 & 18 of the CIE A-level Biology specification through the use of a wide range of tasks to engage and motivate the students. There are plenty of opportunities for the students to assess their current understanding through the completion of exam-style questions and also to check on their prior knowledge by making links to earlier topics.
The following specification points are covered by these lessons:
Topic 17.1: Variation
The differences between continuous and discontinuous variation
Using the t-test to compare the variation of two different populations
The importance of genetic variation in selection
Topic 17.2: Natural and artificial selection
Natural selection
Explain how environmental factors can act as stabilising, disruptive and directional forces of natural selection
Explain how the founder effect and genetic drift may affect allele frequencies in populations
Use the Hardy-Weinberg principle
Topic 17.3: Evolution
The molecular evidence that reveals similarities between closely related organisms
Explain how speciation may occur
Topic 18.1: Biodiversity
Define the terms species, ecosystem and niche
Explain that biodiversity is considered at three levels
Explain the importance of random sampling in determining the biodiversity of an area
Use suitable methods to assess the distribution and abundance of organisms in a local area
Use the Spearman’s rank correlation to analyse relationships between data
Use Simpson’s index of diversity
Topic 18.2: Classification
The classification of species into taxonomic hierarchy
The characteristic features of the three domains
The characteristic features of the kingdoms
Explain why viruses are not included in the three domain classification
Topic 18.3: Conservation
The reasons for the need to maintain biodiversity
Methods of protecting endangered species
The roles of organisations like the WWF and CITES in local and global conservation
If you would like to sample the quality of the lessons that are included in this bundle then download the following as these have been shared for free:
Continuous and discontinuous variation
Molecular evidence & evolution
Spearman’s rank correlation
WWF, CITES and conservation
It is estimated that it will take up to 2 months of A-level Biology teaching time to cover the detail included in these lessons
This lesson describes how to use the Spearman’s rank correlation to analyse the relationships between the distribution of species and abiotic and biotic factors. The PowerPoint and accompanying exam-style question are the first lesson in a series of 2 which have been designed to cover point 18.1 (e) of the CIE A-level Biology specification and challenges the students on their knowledge of the t-test as covered in topic 17 as well as preparing students for the next lesson on the use of the Pearson’s linear correlation formula.
As with the lessons on the t-test and Simpson’s index of diversity, a step by step guide is used to walk the students through the use of the formula to generate the rank coefficient and to determine whether there is a positive correlation, no correlation or a negative correlation. The students are also reminded of the null hypothesis and will be shown how to accept or reject this hypothesis and to determine significance. The students will work through an example with the class and then are given the opportunity to apply their newly-acquired knowledge to an exam-style question which assesses whether there is a relationship between light intensity and % plant cover in a habitat. The mark scheme is displayed on the PowerPoint so the students can assess their understanding and address any misconceptions that may arise
This lesson describes how to use the Spearman’s rank correlation coefficient to consider the relationship between two sets of data. The PowerPoint and accompanying exam-style question are part of the final lesson in a series of 3 which have been designed to cover point 4.2.2 (f) of the OCR A-level Biology A specification. The previous two lessons described the different types of variation and explained how to calculate the standard deviation and how to use the Student’s t-test to compare two means.
As with the previous lesson, a step by step guide is used to walk the students through the use of the formula to generate the rank coefficient and to determine whether there is a positive correlation, no correlation or a negative correlation. The students are also reminded of the null hypothesis and will be shown how to accept or reject this hypothesis and to determine significance. The students will work through an example with the class and then are given the opportunity to apply their newly-acquired knowledge to an exam-style question. The mark scheme is displayed on the PowerPoint so they can assess their understanding
This lesson describes the t-test can be used to compare the variation of two different populations. The detailed PowerPoint and accompanying resources have been designed to cover point 17.1 [c] of the CIE A-level Biology specification and also explains how to calculate the standard deviation to measure the spread of a set of data as this value is needed in the t-test formula
A step by step guide walks the students through each stage of the calculation of the standard deviation and gets them to complete a worked example with the class before applying their knowledge to another set of data in an exam-style question. This data looks at the birth weights of humans on one day in the UK and this is used again later in the lesson to compare against the birth weights of babies in South Asia when using the t-test. The null hypothesis is introduced and students will learn to accept or reject this based upon a comparison of their value against one taken from the table based on the degrees of freedom.
