This lesson describes how the standard deviation and the t-test are used to analyse data. The detailed PowerPoint and accompanying resources are part of the first lesson in a series of 2 lessons that have been designed to cover point 10.1 (vi) of the Edexcel A-level Biology B specification. The next lesson, which uses skills covered in this lesson and has also been uploaded, describes how to analyse data using the Spearman rank correlation coefficient 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. 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 student’s t-test. The null hypothesis is re-introduced, as it will encountered when considering the chi squared test in topic 8, 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.

This lesson describes the movement of water from the root to the leaf and includes the transpiration stream and the cohesion-tension theory. The PowerPoint and accompanying resources have been designed to cover point (n) of topic 3 in AS unit 2 of the WJEC A-level Biology specification This lesson has been written to follow on from a previous lesson, which finished with the description of the transport of the water and mineral ions from the endodermis to the xylem. Students are immediately challenged to use this knowledge to understand root pressure and the movement by mass flow down the pressure gradient. Moving forwards, time is taken to study the details of transpiration pull and the interaction between cohesion, tension and adhesion in capillary action is explained. Understanding is constantly checked through a range of tasks and prior knowledge checks are also written into the lesson to challenge the students to make links to previously covered topics such as the structure of the transport tissues. The final part of the lesson considers the journey of water through the leaf and ultimately out of the stomata in transpiration. A step by step guide using questions to discuss and answer as a class is used to support the students before the final task challenges them to summarise this movement out of the leaf.

This lesson describes the structure of DNA as a double-stranded polymer coiled into a double helix and focuses on nucleotides as the monomers. The PowerPoint and accompanying resources have been designed to cover the detail of point 3.4 of the Edexcel GCSE Biology & Combined Science specifications. The lesson begins with a reveal of the acronym DNA and students will learn that this stands for deoxyribonucleic acid. There is a focus on the use and understanding of key terminology throughout the lesson so time is taken to look at the meanings of the prefixes poly and mono as well as the suffix -mer. This leads into the description of DNA as a polymer which is made up of many monomers known as nucleotides. Students will be introduced to the three components of a DNA nucleotide and will learn that four different bases can be attached to the sugar. An observational task is used to get them to recognise that DNA consists of two strands and that complementary bases are joined by hydrogen bonds. Understanding checks are interspersed throughout the lesson along with mark schemes so that students can assess their progress

A fully resourced lesson which includes an informative lesson presentation (25 slides) and an associated worksheet that show students how to give answers to a certain number of significant figures. The answers to questions in Science are often required to be given in significant figures and this lesson guides students through this process, including the rules of rounding that must be applied for success to be likely. This lesson has been designed for GCSE students but is suitable for KS3

A fully-resourced lesson, which has been designed for GCSE students, and includes an engaging and informative lesson presentation (37 slides) and differentiated worksheets. This lesson explores the type of cell division known as meiosis and focuses on the use of key terminology so that students can apply their knowledge to any organism that carries out this division, and not just humans. For this reason, time is taken at the start of the lesson to go over the meaning of the terms, diploid and haploid. Students are also taught how to think about the quantity of DNA inside a cell in terms of n, so that they can see and understand how this quantity changes through the cell cycle. They are encouraged to fill in a table at each stage of the cycle to show the quantity of DNA. In this way, students will understand how a diploid parent cell goes through interphase and as a result of DNA replication, the quantity of DNA is 4n as the first meiosis division is about to start. Although this could be viewed as high end knowledge, the format of this lesson should allow all abilities to understand and therefore have more chance of being successful with meiosis questions. Students are encouraged to think for themselves to work out how many daughter cells will result at the end of two divisions and to consider the quantity of DNA found inside those cells. At this stage of the lesson, students have to summarise all they have learnt into two key points (as shown on the cover image). The remainder of the lesson gives them the opportunity to apply their knowledge with a range of questions and it is not until right at the end that they are allowed to finally relate this cell division to humans. Although this lesson has been primarily designed for GCSE students (14 - 16 year olds in the UK), it is highly suitable for A-level lessons, especially if a teacher wants to recap on this cell division before extending knowledge.

This fully-resources lesson looks at the phenomenon known as the Bohr effect and describes and explains how an increased carbon dioxide concentration affects the dissociation of oxyhaemoglobin. The PowerPoint has been designed to cover the second part of point 3.1.2 (j) of the OCR A-level Biology A specification and continually ties in with the previous lesson on the role of haemoglobin. The lesson begins with a terminology check to ensure that the students can use the terms affinity, oxyhaemoglobin and dissociation. In line with this, they are challenged to draw the oxyhaemoglobin dissociation curve and are reminded that this shows how oxygen associates with haemoglobin but how it dissociates at low partial pressures. Moving forwards, a quick quiz is used to introduce Christian Bohr and the students are given some initial details of his described effect. This leads into a series of discussions where the outcome is the understanding that an increased concentration of carbon dioxide decreases the affinity of haemoglobin for oxygen. The students will learn that this reduction in affinity is a result of a decrease in the pH of the cell cytoplasm which alters the tertiary structure of the haemoglobin. Opportunities are taken at this point to challenge students on their prior knowledge of protein structures as well as the bonds in the tertiary structure. The lesson finishes with a series of questions where the understanding and application skills are tested as students have to explain the benefit of the Bohr effect for an exercising individual. These questions are differentiated to allow students of differing abilities to access the work and to be challenged

This is a fully-resourced revision lesson that uses a combination of exam questions, understanding checks, quick tasks and quiz competitions to enable students to assess their understanding of the content found within Module 5.2.1 (Photosynthesis) of the OCR A-level Biology A specification. The sub-topics and specification points that are tested within the lesson include: The interrelationship between photosynthesis and respiration The structure of a chloroplast The importance of photosynthetic pigments in photosynthesis The light dependent stage of photosynthesis The fixation of carbon dioxide and the light independent stage of photosynthesis Factors affecting photosynthesis Students will be engaged through the numerous quiz rounds such as “Can you DEPEND on your knowledge” and “Photosynthesising the SAFE way” whilst crucially being able to recognise those areas which require their further attention during general revision or during the lead up to the actual A-level terminal exams

This is a fully-resourced REVISION lesson which challenges the students on their knowledge of the content in TOPIC B5 (Genetics) of the Edexcel GCSE Combined Science specification. The lesson uses an engaging PowerPoint (63 slides) and accompanying worksheets to motivate students whilst they assess their understanding of this topic. A range of exam questions, quick tasks and quiz competitions are used to test the following sub-topics: Recognising and using genetic terminology in context Constructing genetic diagrams to calculate offspring percentages for diseases caused by dominant and recessive alleles The sex chromosomes and sex determination Meiosis and the formation of haploid daughter cells The structure of DNA Extracting DNA from a fruit Genetic and environmental variation Mutations and their effect on the phenotype The mathematical element of the course is also tested throughout the lesson and students are given helpful hints on exam techniques and how to structure answers. This resource is suitable for use at the end of topic B3 or in the lead up to mocks or the actual GCSE exams.

This fully-resourced lesson describes how the release of ADH from the pituitary gland controls mammalian plasma concentration. The engaging PowerPoint and accompanying resources have been designed to cover the detail included in point 9.9 (iv) of the Edexcel A-level Biology B specification and also includes details of the roles of the osmoreceptors in the hypothalamus. The principles of homeostasis and negative feedback were covered in an earlier lesson in topic 9, so this lesson acts to build on that knowledge and challenges them to apply their knowledge. A wide range of activities have been included in the lesson to maintain motivation and engagement whilst the understanding and prior knowledge checks will allow the students to assess their progress as well as challenge themselves to make links to other Biology topics. The lesson begins with a discussion about how the percentage of water in urine can and will change depending on the blood water potential. Students will quickly be introduced to osmoregulation and they will learn that the osmoreceptors and the osmoregulatory centre are found in the hypothalamus. A considerable amount of time is taken to study the cell signalling between the hypothalamus and the posterior pituitary gland by looking at the specialised neurones (neurosecretory cells). Links are made to the topics of neurones, nerve impulses and synapses and the students are challenged to recall the cell body, axon and vesicles. The main section of the lesson forms a detailed description of the body’s detection and response to a low blood water potential. The students are guided through this section as they are given 2 or 3 options for each stage and they have to use their knowledge to select the correct statement. The final task asks the students to write a detailed description for the opposite stimulus and this task is differentiated so those who need extra assistance can still access the work.

This lesson describes how the immune system uses molecules on the surface of a cell to identify it, focusing on the identification of pathogens by their antigens. The PowerPoint and accompanying resources which are differentiated are part of the 1st lesson in the series of 7 that cover the content detailed in topic 2.4 of the AQA A-level Biology specification. As this is the first lesson in topic 2.4, it has been specifically planned to introduce a number of key concepts which include phagocytosis, T and B cells, antibodies and memory cells so that students are prepared for upcoming lessons. The lesson begins by challenging the students to use their knowledge of cells to recall the common internal components of a cell before they are informed that all cells also have molecules on their outer membrane. Students will recognise that these molecules are used by the immune system for identification before a quick quiz competition reveals that this allows toxins, abnormal body cells and pathogens to be identified. Moving forwards, the next part of the lesson focuses on the antigens that are found on the outside of a pathogen and links are made to upcoming lesson topics which include: phagocytosis following the identification of a pathogen antigen-presentation by macrophages and dendritic cells production of antibodies which are specific to the antigens the use of antigens in a vaccination program The final task challenges the students to describe and explain how antigen variability will affect disease and disease prevention and this task has been differentiated two ways to allow students of differing abilities to be challenged and supported.

This fully-resourced lesson describes how the functional differences of the retinal rod and cone cells is related to their structures. The detailed PowerPoint and accompanying resources are part of the 2nd in a series of 2 lessons that have been designed to cover the details included in point 6.1.2 of the AQA A-level Biology specification. However, as explained at the start of the lesson, it has been specifically planned to be taught after the lessons in topic 6.3, so that students are aware and understand the meaning of terms such as depolarisation and hyperpolarisation. It is likely that students will be aware that the human retina contains rod and cone cells, so this lesson builds on that knowledge and adds the detail needed at this level. Over the course of the lesson, students will learn that these cells contain different optical pigments and that this feature along with their differing connectivity to the bipolar neurones means that they have different sensitivities to light, colour perception and visual acuity. Exam-style questions are interspersed throughout to check on current understanding and also make links to previously covered topics. For example, students are challenged to recognise a description of the mitochondria so they can discover that this cell structure is found in the inner segment where it is responsible for generating the ATP needed to pump sodium ions out of the cells. As detailed above, this lesson ties in closely with topic 6.3 and students will be expected to make links to synapses and to the changes in membrane potential that occur when sodium ions move in or out of a cell

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

This lesson 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 uses and implications of pre-implantation genetic diagnosis, amniocentesis and chorionic villus sampling. The lesson PowerPoint and accompanying worksheets have been primarily designed to cover point 2.17 of the Edexcel International A-level Biology specification but there are regular checks of their knowledge of the content of topic 2, where topics including monohybrid inheritance and cystic fibrosis are tested. The lesson begins by challenging them to use this prior knowledge of topic 2 to identify the letters in the abbreviations PGD and CVS. The involvement of IVF to obtain the embryos (or oocytes) is then discussed and a series of exam-style questions are used to get them to understand how this method screens embryos prior to implantation, so that those identified as having genetic diseases or being carriers are not inserted into the female’s uterus. Mark schemes for all of the questions included in this lesson are embedded into the PowerPoint so students can constantly assess their progress. Moving forwards, Down syndrome (trisomy 21) is used as an example of a chromosomal abnormality that can be tested for using CVS or amniocentesis. Time is taken to describe the key details of both of these procedures so students have a clear understanding of the implications and the invasiveness to the female being tested. The link between amniocentesis and an increased risk of miscarriage is considered and the results of a 2006 study are used to challenge them on their data skills.