This lesson describes the adaptations of gas exchange surfaces in single-celled organisms, insects, bony fish and dicotyledonous plants. The PowerPoint and accompanying worksheets are part of the first lesson in a series of 6 lessons that have been designed to cover the detail of point 3.2 (Gas exchange) of the AQA A-level Biology specification. The lesson has been intricately planned to challenge the students on their understanding of the surface area to volume ratio (as covered in the previous lesson) and to make direct links to upcoming lessons on gas exchange and transport systems in humans. The lesson begins by explaining that single-celled organisms are able to diffuse oxygen and carbon dioxide across their body surface but that as organisms increase in size and their SA/V ratio decreases, they need adaptations at their gas exchange surfaces to be able to obtain the oxygen to meet their metabolic demands. This leads into the next part of the lesson which describes the roles of the following structures in insects and bony fish: spiracles, tracheae, tracheoles and tracheole fluid operculum, gill arch, gill filaments and lamellae The next task challenges the students to use their knowledge of topics 1 and 2 to come up with the letters that form the key term, countercurrent flow. This is a key element of the lesson and tends to be a principle that is poorly understood, so extra time is taken to explain the importance of this mechanism. Students are shown two diagrams, where one contains a countercurrent system and the other has the two fluids flowing in the same direction, and this is designed to support them in recognising that this type of system ensures that the concentration of oxygen is always higher in the oxygenated water than in the blood in the lamellae. The final part of the lesson describes the role of the stomata and the mesophyll cells in the gas exchange of a dicotyledonous plant. Students will learn that guard cells contain chloroplasts which generate ATP and then they are challenged to order a series of statements to form a description of the events that result in the opening of the stomata. The differing structures of the spongy mesophyll and palisade mesophyll cells are then considered before the students are challenged to explain how carbon dioxide moves through the leaf after entering via the stomata and then how water vapour and oxygen leave. Clear links are made to the loss of water vapour by transpiration so students are prepared for the lessons covering this biological process later in topic 3.

This lesson guides students through the use of the chi-squared test to determine the significance of the difference between observed and expected results. It is fully-resourced with a detailed PowerPoint and differentiated worksheets that have been designed to cover point 8.2 (vi) of the Edexcel A-level Biology B specification The lesson includes a step-by-step guide to demonstrates how to carry out the test in small sections. At each step, time is taken to explain any parts which could cause confusion and helpful hints are provided to increase the likelihood of success in exam questions on this topic. Students will understand how to use the phenotypic ratio to calculate the expected numbers and then how to find the critical value in order to compare it against the chi-squared value. A worked example is used to show the working which will be required to access the marks and then the main task challenges the students to apply their knowledge to a series of questions of increasing difficulty. This is the final lesson of topic 8.2 (transfer of genetic information) and links are made throughout the lesson to earlier parts of this topic such as dihybrid inheritance as well as to earlier topics like meiosis

This fully-resourced lesson looks at the structure of genes and explores their role as a base sequence on DNA that codes for the amino acid sequence of a polypeptide. Both the PowerPoint and accompanying resource have been designed to cover the second part of point 4.1 of the AQA A-level Biology specification and has been written to specifically tie in with the previous lesson on DNA in prokaryotes and eukaryotes. The lesson begins with a prior knowledge check as the students have to recognise the key term chromosome from a description involving DNA and histones. This allows genes, as sections of a chromosome, to be introduced and the first of a number of quiz rounds is then used to get the students to meet the term locus so that they can understand how each gene has a specific location on a chromosome. Whenever possible, opportunities are taken to make links to the other parts of the AQA specification and this is utilised here as students are reminded that alternative versions of a gene (alleles) can be found at the locus. Moving forwards, students will learn that 3 DNA bases is a triplet and that each triplet codes for a specific amino acid. At this point, the genetic code is introduced and students are challenged to explain how the code contains 64 different triplets. By comparing this number against the number of different amino acids in proteins, students will see how each amino acid is encoded for by more than one triplet and how this explains the degenerate nature of the genetic code. Again, an opportunity is taken to link to gene mutations. Finally, the students are told that most of the nuclear DNA in a eukaryote doesn’t code for a polypetptide and that even within a gene, there are coding and non-coding regions known as exons and introns respectively. The last section of the lesson uses a quiz round to check on all of the key terms which have been met in the two lessons on DNA, genes and chromosomes.

This lesson describes the relationship between the structure and function of the xylem and phloem in transport. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 4.7 (i) of the Edexcel A-level Biology B specification. The lessons begins by challenging the students to identify the substances that a plant needs for the cellular reactions, where they are absorbed and where these reactions occur in a plant. The aim of this task is to get the students to recognise that water and mineral ions are absorbed in the roots and needed in the leaves whilst the products of photosynthesis are in the leaves and need to be used all over the plant. Students will be reminded that the xylem and phloem are part of the vascular system responsible for transporting these substances and then the rest of the lesson focuses on linking structure to function. A range of tasks which include discussion points, exam-style questions and quick quiz rounds are used to describe how lignification results in the xylem as a hollow tube of xylem cells to allow water to move as a complete column. They will also learn that the narrow diameter of this vessel allows capillary action to move water molecules up the sides of the vessel. The same process is used to enable students to understand how the structures of the companion cells allows assimilates to be loaded before being moved to the sieve tube elements through the plasmodesmata.

A highly engaging and information lesson presentation (46 slides) which guides students through the steps needed to construct an accurate distance-time graph and then teaches them how to interpret the motions that are shown by the different lines. The lesson challenges the students to work out the type of graph that should be used to present the data and to suggest which factor from the blank table should go on the x-axis. Using the results that they obtain, a step-by-step guide is used to walk students through constructing the graph. This includes deciding on scales to ensure they are even and make the most of the available paper. Student will see the four key terms of motion associated with these graphs (acceleration, deceleration, constant speed and stationary) and will be able to use their graph to work out which lines go with which motion. Moving forwards, students will be shown how to calculate speed from the graph. There are progress checks throughout the lesson so that students can assess their understanding of the topic. This lesson has been designed for GCSE students but is perfectly suitable for KS3 students too.

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 detailed and engaging lesson covers the detail of specification points 5.1.4 (c and d) of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply an understanding of the histology of the pancreas and the control of insulin secretion. There is a particular emphasis on structure throughout the lesson so that students can recognise the exocrine and endocrine tissues of the pancreas as well as describe their specific functions. The lesson begins with a list of endocrine glands and the students are challenged to select the gland which also has exocrine functions. This leads into a focus on the exocrine tissues of the pancreas, beginning with the enzymes that are secreted and form pancreatic juice. Students will discover how groups of these cells are called acini and the secretion of the enzymes into the lobule at the centre will lead to the intralobular ducts and finally the formation of the pancreatic duct. Moving forwards, students are introduced to the Islets of Langerhans and the specialised alpha and beta cells that are found within this endocrine tissue. The rest of this lesson looks at how the release of insulin from the beta cells is controlled. Some of the structures and substances involved have been met in earlier topics so a fun quiz round is used to see which students can recall these parts first. A series of questions and discussion points challenge the students to verbalise answers and to discuss key points so that the cascade of events that take place in the lead up to the release can be considered. In the final task, students have to describe these events in detail and this task has been differentiated so that students of differing abilities can access the work. This lesson has been specifically designed for students on the OCR A-level Biology A course and ties in well with the other lessons from module 5.1.4 on the control of blood glucose concentration and diabetes mellitus type I and II

The Pearson Edexcel A-level Biology A (Salters Nuffield) specification states that a minimum of 10% of the marks across the assessment papers will require the use of mathematical skills. This revision lesson has been designed to include a wide range of activities that challenge the students on these exact skills because success in the maths in biology questions can prove the difference between one grade and the next! Step-by-step guides are used to walk students through the application of a number of the formulae and then exam-style questions with clear mark schemes (which are included in the PowerPoint) will allow them to assess their progress. Other activities include differentiated tasks, group discussions and quick quiz competitions such as “FROM NUMBERS 2 LETTERS” and “YOU DO THE MATH”. The lesson has been written to cover as much of the mathematical requirements section of the specification as possible but the following have been given particular attention: Hardy-Weinberg equation Chi-squared test Calculating size Converting between quantitative units Standard deviation Estimating populations of sessile and motile species Percentages and percentage change Cardiac output Geometry Due to the detail and extensiveness of this lesson, it is estimated that it will take in excess of 2/3 hours of A-level teaching time to work through the activities and it can be used throughout the duration of the course

This lesson is fully-resourced, engaging and detailed and explains how the Contact process is one of the 3 steps involved in making sulfuric acid. The PowerPoint and accompanying resources, which are differentiated, have been written to cover point C6.1(d) of the OCR Gateway A GCSE Chemistry specification. The lesson begins with a challenge where students have to use the 1st letters of the answers to questions on previously covered topics to come up with the word CONTACT. At this point, the students are introduced to the contact process as the 2nd step in a 3 stage process to make sulfuric acid. The lesson goes through the details of each of the 3 steps but particular time is spent exploring the conditions needed for the contact process in step 2. Students are continuously tested on their knowledge of reversible reactions and the key concepts to do with equilibrium position and equilibrium yield are explained so they can understand how the conditions of 2 atmospheres and 450 degrees celsius are chosen. Again through a prior knowledge check of empirical formula, the students will be introduced to vanadium oxide as the catalyst. As well as exam-style questions with displayed answers to check on current understanding, there are discussion points as well as quick quiz competitions to introduce key terms and values in a memorable way.

This fully-resourced lesson describes how selection pressures act on a gene pool and cause stabilising, directional and disruptive selection. The PowerPoint and accompanying resources have been designed to cover point 8.3 (i) of the Edexcel A-level Biology B specification which states that students should be able to identify each type of selection by its effect on different phenotypes. The lesson begins with an introduction to the mark, release, recapture method to calculate numbers of rabbits with different coloured fur in a particular habitat. This shows changes in numbers of the organisms and sketch graphs are then constructed to show these changes in the population size. A quick quiz competition is used to engage the students whilst introducing the names of the three main types of selection before a class discussion point encourages the students to recognise which specific type of selection is represented by the rabbits. Key terminology including intermediate and extreme phenotypes and selection pressure are used to emphasise their importance during explanations. A change in the environment of the habitat and a change in the numbers of the rabbits introduces directional selection before students will be given time to discuss and to predict the shape of the sketch graph for disruptive selection. Students are challenged to apply their knowledge in the final task of the lesson by choosing the correct type of selection when presented with details of a population and answer related questions.

This fully-resourced lesson describes how DNA is replicated semi-conservatively, including the roles of DNA helicase, polymerase and ligase. The detailed PowerPoint and accompanying resources have been designed to cover point 1.4 (ii) of the Edexcel A-level Biology B specification The main focus of this lesson is the roles of DNA helicase in the breaking of the hydrogen bonds between nucleotide bases, DNA polymerase in forming the growing nucleotide strands and DNA ligase in the joining of the nucleic acid fragments. Time is taken to explain key details, such as the assembly of strands in the 5’-to-3’ direction, so that the continuous manner in which the leading strand is synthesised can be compared against that of the lagging strand. The students are constantly challenged to make links to previous topics such as DNA structure and hydrolysis reactions through a range of exam questions and answers are displayed so that any misconceptions are quickly addressed. The main task of the lesson asks the students to use the information provided in the lesson to order the sequence of events in DNA replication before discussing how the presence of a conserved strand and a newly built strand in each new DNA molecule shows that it is semi-conservative.

This fully-resourced lesson describes how the cohesion-tension model explains the transport of water from the roots to the shoots. The detailed PowerPoint and accompanying resources have been designed to cover point 4.7 (iii) of the Edexcel A-level Biology B specification This lesson has been written to follow on from the end of the 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 then the main focus is the interaction between cohesion and tension. The role of adhesive forces in capillary action is also 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.

This engaging lesson covers the detail of the 2nd part of specification point 6.2.2 of the AQA A-level Biology specification which states that students should be able to explain temporal and spatial summation as well as understand inhibition by inhibitory synapses. This is a topic which is generally poorly understood by students or brushed over so considerable time has been taken to design the activities to motivate the students so that the content is memorable whilst still being covered in detail. Links are continually made to earlier topics in this module such as synapses and generator potentials but also to topics covered in the previous year and still to be covered. The lesson begins by challenging the students to recognise a description of generator potential and they will then discover that this is also known as an EPSP. Students will recall that a small depolarisation may not lead to the opening of the voltage gated channels and therefore the full depolarisation which is needed for the initiation of an action potential and will discuss how this problem could be overcome. Lots of discussion points like this are included in the lesson to encourage the students to challenge and debate why a particular process of mechanism occurs. Students will therefore learn that EPSPs can be combined and this is known as summation. A quiz round is used to introduce temporal and spatial summation. Moving forwards, students are presented with a number of examples where they have to decide why type of summation is involved. Again, the lesson has been written to include real-life examples such as chronic pain conditions so the chances of the content sticking is increased. The final part of the lesson introduces IPSPs and the effect of these on summation and action potentials is discussed. This lesson has been designed for students studying on the AQA A-level Biology course and ties in well with the other uploaded lessons from topic 6 which include cholinergic synapses and neuromuscular junctions, sensory receptors and nerve impulses

This detailed lesson has been planned to cover the 1st part of specification point 6.4.3 of the AQA A-level Biology specification which states that students should be able to describe the detailed structure of the nephron and understand its role in ultrafiltration, selective reabsorption and osmoregulation. The lesson was designed at the same time as the other lessons in this topic on ultrafiltration, selective reabsorption and osmoregulation so that a common theme runs throughout and students can build up their knowledge gradually in order to develop a deep understanding of this organ. Students will come to recognise the renal cortex and renal medulla as the two regions of the kidney and learn the parts of the nephron which are found in each of these regions. Time is taken to look at the vascular supply of this organ and specifically to explain how the renal artery divides into the afferent arterioles which carry blood towards the glomerulus and the efferent arterioles which carry the blood away. The main task of the lesson challenges the students to relate structure to function. Having been introduced to the names of each of the parts of the nephron, they have to use the details of the structures found at these parts to match the function. For example, they have to make the connection between the microvilli in the PCT as a sign that this part is involved in selective reabsorption. This lesson has been designed for students studying on the AQA A-level Biology course

This detailed lesson describes the the structure and function of the motor neurones that form the autonomic nervous system and is responsible for automatic responses. The engaging PowerPoint and accompanying resource have been designed to cover point 9.4 (v) of the Edexcel A-level Biology B specification and describes the sympathetic and parasympathetic divisions and how they act antagonistically. The lesson begins with a focus on the types of effectors that will be connected to the CNS by autonomic motor neurones. Students will learn that effectors which are not under voluntary control such as cardiac muscle, smooth muscle and glands will be innervated by these neurones. Moving forwards, a quick quiz competition is used to introduced ganglia as a structure which connects the two or more neurones involved in the cell signalling between the CNS and the effector. This leads into the discovery of the two divisions and students will begin to recognise the differences between the sympathetic and parasympathetic systems based on function but also structure. The remainder of the lesson looks at the differing effects of these two systems. This lesson has been written to tie in with the lesson on the organisation of the mammalian nervous system which was covered earlier in this topic

This lesson explains that autosomal linkage results from the presence of alleles on the same chromosome and uses biological examples to demonstrate this concept. The PowerPoint and accompanying worksheets have been designed to cover point 8.2 (iv) of the Edexcel A-level Biology B specification and supports students in the formation of their descriptions of how these results of these crosses can be explained by the events of meiosis (crossing over) This is a difficult topic which can be poorly understood by students so extra time was taken during the planning to split the concept into small chunks. There is a clear focus on using the number of parent phenotypes and recombinants in the offspring as a way to determine linkage and suggest how the loci of the two genes compare. Important links to other topics such as crossing over in meiosis are made to enable students to understand how the random formation of the point of contact (chiasma) determines whether new phenotypes will be seen in the offspring or not. Linkage is an important cause of variation and the difference between observed and expected results and this is emphasised on a number of occasions and a link to the chi squared test which is covered in an upcoming lesson is also made. The main task of the lesson act as understanding check where students are challenged to analyse the results of genetic crosses involving the inheritance of the ABO blood group gene and the nail-patella syndrome gene n humans and also the inheritance of body colour and wing length in Drosophila.

This detailed lesson describes how an endotherm regulates its temperature through behaviour and also physiologically. The engaging PowerPoint and accompanying resources have been designed to cover specification point 9.9 (vii) of the Edexcel A-level Biology B specification and includes descriptions of the roles of the autonomic nervous system, thermoreceptors, hypothalamus and skin. A wide range of activities have been written into this lesson so that students remain motivated throughout and take a genuine interest in the content. Understanding checks allow the students to assess their progress whilst the prior knowledge checks on topics such as enzymes and denaturation demonstrate the importance of being able to make connections and links between topics from across the specification. In addition to these checks, quiz competitions like HAVE an EFFECT which is shown in the cover image are used to introduce key terms and values in a fun and memorable way. The lesson begins by introducing the key term, endotherm, and challenging students to use their prior knowledge and understanding of terminology to suggest what this reveals about an organism. Moving forwards, students will learn how the heat generated by metabolic reactions is used as a source of internal heat. The main part of the lesson focuses on thermoregulation in humans (mammals) and time is taken to focus on the key components, namely the sensory receptors, the thermoregulatory centre in the hypothalamus and the responses brought about by the skin. The important details of why the transfer of heat energy between the body and the environment actually leads to a decrease in temperature are explored and discussed at length to ensure understanding is complete. Students are challenged to write a detailed description of how the body detects and responds to a fall in body temperature and this task is differentiated for those students who need some extra assistance. The peripheral thermoreceptors are introduced and this leads into the final section of the lesson that considers behavioural responses in humans and other animals.

This lesson describes the structure and functions of the adrenal glands, and includes the hormones secreted by the cortex and the medulla. The detailed PowerPoint and accompanying resources have been designed to cover point 5.1.4 (b) of the OCR A-level Biology A specification This lesson has been planned to closely tie in with the previous lesson on endocrine communication, and specifically the modes of action of peptide and steroid hormones. At the start of the lesson, the students have to use the knowledge acquired in this last lesson to reveal the key term cortex and this leads into the description of the structure of the adrenal glands in terms of the outer region and the inner region known as the medulla. The main part of the lesson focuses on the range of physiological responses of the organs to the release of adrenaline. Beginning with glycogenolysis, the need for adrenaline to bind to adrenergic receptors is described including the activation of cyclic AMP. A quiz competition is used to introduce other responses including lipolysis, vasodilation, bronchodilation and an increase in stroke volume. Links to previous topics are made throughout the lesson and students are challenged on their knowledge of heart structure and polysaccharides. The final part of the lesson introduces the three zones of the adrenal cortex and the steroid hormones that they produce along with their functions. Once again, a series of exam-style questions are used to challenge their ability to apply their understanding to an unfamiliar situation and to make biological links and the mark schemes are embedded in the PowerPoint.

This fully-resourced lesson guides students through the use of the Hardy-Weinberg equation to monitor changes in allele frequencies in a population. The detailed PowerPoint and differentiated practice questions worksheets have been designed to cover point 8.3 (iv) of the Edexcel A-level Biology B specification The lesson begins with a focus on the equation to ensure that the students understand the meaning of each of the terms. The recessive condition, cystic fibrosis, is used as an example so that students can start to apply their knowledge and assess whether they understand which genotypes go with which term. Moving forwards, a step-by-step guide is used to show students how to answer a question. Tips are given during the guide so that common misconceptions and mistakes are addressed immediately. The rest of the lesson gives students the opportunity to apply their knowledge to a set of 3 questions, which have been differentiated so that all abilities are able to access the work and be challenged

This detailed lesson describes the process of translation at the ribosome and includes detailed descriptions of the roles of the mRNA, tRNA and rRNA. The PowerPoint and accompanying resources have been designed to cover the second part of point 1.4 (vi) of the Edexcel A-level Biology B specification and this lesson also includes continual links to the previous lessons in this topic on transcription and the structure of DNA and RNA. Translation is a topic which is often poorly understood and so this lesson has been written with the aim of supporting the students to answer the different types of questions that can arise. The lesson begins by challenging the students to consider why it is so important that the amino acids are assembled in the correct order during the formation of the chain. Moving forwards, a quick quiz round called “LOST IN TRANSLATION” is used to check on their prior knowledge of the mRNA strand, the tRNA molecules and the ribosomes. The next task involves a very detailed description of translation that has been divided into 14 statements which the students have to put into the correct order. By giving them a passage of this detail, they can pick out the important parts to use in the next task where they have to answer shorter questions worth between 3 and 4 marks. These types of questions are common in the assessments and by building up their knowledge across the lesson, their confidence to tackle this type of question should increase. The final two tasks of the lesson involve another quiz, where the teams compete to transcribe and translate in the quickest time before using all that they have absorbed to answer some questions which involve the genetic code and the mRNA codon table