This lesson focuses on the nature of the genetic code in terms of being near universal, non-overlapping and degenerate and specifically focuses on this latter term to explain how a mutation may not result in a change to the sequence of amino acids. The PowerPoint has been designed to cover point 2.1.3 (f) of the OCR A-level Biology A specification and there are clear links to gene mutations which students will meet in module 6. The lesson begins by introducing the terms near universal and non-overlapping in addition to degenerate. A quick quiz competition is used to generate the number 20 so that the students can learn that there are 20 proteinogenic amino acids in the genetic code. This leads into a challenge, where they have to use their prior knowledge of DNA to calculate the number of different DNA triplets (64) and the mismatch in number is then discussed and related back to the lesson topic. Moving forwards, base substitutions and base deletions are briefly introduced so that they can see how although one substitution can change the primary structure, another will change the codon but not the encoded amino acid. The lesson concludes with a brief look at the non-overlapping nature of the code so that the impact of a base deletion (or insertion) can be understood when covered in greater detail in module 6.

This lesson describes how solutes are selectively reabsorbed in the proximal tubule. The PowerPoint and accompanying resource have been designed to cover the first part of specification point 7.20 of the Edexcel International A-level Biology specification and builds on the knowledge gained in the previous lessons on the microscopic structure of the nephron and ultrafiltration. The lesson begins by challenging the students to recall the substances that are found in the glomerular filtrate so that each of them can be considered over the course of the rest of the lesson. Moving forwards, the first of the numerous discussion points which are included in the lesson is used to get students to predict the component of the filtrate which won’t be found in the urine when they are presented with pie charts from each of these situations. Upon learning that glucose is 100% reabsorbed, along with most of the ions and some of the water, the rest of the lesson focuses on describing the relationship between the structure of the PCT and the function of selective reabsorption. Again, this section begins by encouraging the students to discuss and to predict which structures they would expect to find in a section of the kidney if the function is to reabsorb. They are given the chance to see the structure (as shown in the cover image) before each feature is broken down to explain its importance. Time is taken to look at the role of the cotransporter proteins to explain how this allows glucose, along with sodium ions, to be reabsorbed from the lumen of the PCT into the epithelial cells. The final part of the lesson focuses on urea and how the concentration of this substance increases along the tubule as a result of the reabsorption of some of the water.

This lesson explains how negative feedback control maintains systems within narrow limits and uses biological examples to describe the meaning of positive feedback. The PowerPoint and accompanying resources have been designed to cover points 7.11 (i) and (ii) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification but have been planned to provide important details for upcoming topics such as the importance of homeostasis during exercise and the depolarisation of a neurone. The normal ranges for blood glucose concentration, blood pH and body temperature are introduced at the start of the lesson to allow students to recognise that these aspects have to be maintained within narrow limits. A series of exam-style questions then challenge their recall of knowledge from topics 1 - 6 as well as earlier in topic 7 to explain why it’s important that each of these aspects is maintained within these limits. The students were introduced to homeostasis at GCSE, so this process is revisited and discussed, so that students are prepared for an upcoming lesson on exercise, as well as for the next part of the lesson on negative feedback control. Students will learn how this form of control reverses the original change and biological examples are used to emphasise the importance of this system for restoring levels to the limits (and the optimum). The remainder of the lesson explains how positive feedback differs from negative feedback as it increases the original change and the role of oxytocin in birth and the movement of sodium ions into a neurone are used to exemplify the action of this control system.

This fully-resourced lesson describes how to calculate the concentration of solution in grams per decimetres cubed and mol per decimetre cubed. The lesson PowerPoint and accompanying questions which are differentiated have been designed to cover points 1.49 & 5.8 of the Edexcel GCSE Chemistry specification. The lesson begins by introducing students to volumes in decimetres cubed and time is taken to ensure that students are able to convert to this measurement from volumes in centimetres cubed. Moving forwards, students are shown how to calculate the concentration in both units through the use of worked examples and then they are challenged to apply this to a series of exam-style questions which have been differentiated so students of differing abilities can access the work

This lesson explains the properties of typical covalent simple molecular compounds and introduces diamond and graphite as giant substances. The lesson PowerPoint and accompanying resource have been primarily designed to cover point 1.34 of the Edexcel GCSE Chemistry & Combined Science specifications but also links to points 1.35 - 1.37 where the structure and uses of the giant covalent substances are described. The lesson begins with a quick recap task where students have to recognise a covalent bond from a description and fill the missing part. Moving forwards, they are introduced to the fact that covalent molecules can be simple or giant. They are then presented with a table showing some properties of covalent molecules and having to group them as simple or giant in the short space of time that the table remains displayed on the board. This task challenges their observational skills, something which will again be tested later in the lesson as they study the structure of graphite and diamond. Time is taken to ensure that key details such as the strong covalent bonds in both sets of molecules is understood and that it is the weak intermolecular forces which are actually responsible for the low melting and boiling points. The last part of the lesson introduces diamond and graphite as allotropes of carbon and students will briefly learn why one of these conducts electricity whilst the other doesn’t. If you want a lesson about these allotropes in more detail, then please look for “Diamond and Graphite”. Progress checks have been written into the lesson at regular intervals so that students are constantly assessing their understanding and so misconceptions are quickly identified.

A concise, fast-paced lesson that looks at the orbits of both natural and artifical satellites. The lesson has been written to build on the student’s knowledge of space from KS3 and add key details such as the gravitational pull between the different celestial objects. Students will learn how the speed of the orbiting object and the gravitational pull ensure that the object remains in orbit and consider what would happen should the speed change. Students are briefly introduced to a number of orbits of artificial satellites as well as the uses. This lesson has been designed for GCSE students

A fast-paced lesson presentation (20 slides) which focuses on the understanding of the scientific term, specific latent heat, and guides students through use of the related equation in energy calculations. This lesson has been written for GCSE students and along with specific heat capacity, these are topics which students regularly say that they do not understand so the aim here has been to embed the key details. The task at the start of the lesson gets students to plot the changing state line for pure water. They have to annotate the line to show the changes in state and then most crucially recognise that when these changes in state occur, there is no change in temperature. Moving forwards, students will meet the additional terms of fusion and vaporisation and then be introduced to the equation. They are reminded that this isn’t an equation that they have to recall, but are expected to apply it and therefore the next few slides focus on the potential difficulties that could be encountered. These include the conversion between units and a mathematical skills check is included at this point so that their ability to move between grams and kilograms and Joules and kiloJoules is tested. Progress checks like this are written into the lesson at regular intervals so the students can constantly assess their understanding.

This fully-resourced lesson covers the meaning of the 9 genetic terms that are detailed in point 2.13 (i) of the Pearson Edexcel A-level Biology (Salters Nuffield) specification as well as four other key terms which will need to be used later in topic 2, 3 and 8. In the following lessons, students are expected to be able to demonstrate and apply their knowledge and understanding of genetic diagrams and phenotypic ratios to show patterns of inheritance and this is only possible with a clear understanding of the genetic terminology that will be used in related exam questions. As some of these terms were met at GCSE, this lesson has been designed to build on this prior knowledge and provide clear explanations as to their meanings as well as numerous examples of their use in both questions and exemplary answers. The main task provides the students with an opportunity to apply their understanding by recognising a dominance hierarchy in a multiple alleles characteristic and then calculating a phenotypic ratio when given a completed genetic diagram. Other tasks include prior knowledge checks, discussion points to encourage students to consider the implementation of the genetic terms and quiz competitions to introduce new terms, maintain engagement and act as an understanding check. The 13 terms are genome, gene, chromosome, gene locus, homologous chromosomes, alleles, dominant, recessive, genotype, phenotype, homozygotes and heterozygotes

This lesson focuses on the nature of the genetic code and specifically focuses on the degenerate nature to make a link to gene mutations which is covered later in topic 2. The PowerPoint has been designed to cover point 2.7 of the Pearson Edexcel A-level Biology (Salters Nuffield) specification which states that students should understand how the descriptive terms triplet code, degenerate and non-overlapping relate to the genetic code. The lesson begins by introducing the terms near universal and non-overlapping in addition to degenerate. A quick quiz competition is used to generate the number 20 so that the students can learn that there are 20 proteinogenic amino acids in the genetic code. This leads into a challenge, where they have to use their prior knowledge of DNA to calculate the number of different DNA triplets (64) and the mismatch in number is then discussed and related back to the lesson topic. Moving forwards, substitutions and deletions are briefly introduced so that they can see how although one substitution can change the primary structure, another will change the codon but not the encoded amino acid. The lesson concludes with a brief look at the non-overlapping nature of the code so that the impact of a base deletion can be understood when covered in greater detail with cystic fibrosis

This concise lesson describes the basic structure of an amino acid and introduces them as the monomers of polypeptides. The engaging PowerPoint has been designed to cover point 2.9 (i) of the Pearson Edexcel A-level Biology A specification and has been specifically written to lead into the next lesson on dipeptides and polypeptides. The lesson begins with a prior knowledge check, where the students have to use the 1st letters of 4 answers to uncover a key term. This 4-letter key term is gene and the lesson begins with this word because it is important for students to understand that these sequences of bases on DNA determine the specific sequence of amino acids in a polypeptide as detailed in specification point 2.8. Moving forwards, the students are given discussion time to work out that there are 64 different DNA triplets and will learn that these encode for the 20 amino acids that are common to all organisms. The main task of the lesson is an observational one, where students are given time to study the displayed formula of 4 amino acids. They are not allowed to draw anything during this time but will be challenged with 3 multiple choice questions at the end. This task has been designed to allow the students to visualise how the 20 amino acids share common features in an amine and an acid group. A quick quiz round introduces the R group and time is taken to explain how the structure of this side chain is the only structural difference, before cysteine is considered in greater detail due to the presence of sulfur atoms. Students are briefly introduced to disulfide bridges so they will recognise how particular bonds form between the R groups in the tertiary structure which is covered in the next lesson. The lesson concludes with one more quiz round called LINK TO THE FUTURE where the students will see the roles played by amino acids in the later part of the course such as translation and dipeptides.

This fully-resourced lesson describes how triglycerides are formed during condensation reactions and compares saturated and unsaturated lipids. The engaging PowerPoint and accompanying worksheets have been designed to cover the points 1.14 (i) & (ii) of the Pearson Edexcel A-level Biology A specification and links are also made to related future topics such as the importance of the myelin sheath for the conduction of an electrical impulse. The lesson begins with a focus on the basic structure and roles of lipids, including the elements that are found in this biological molecule and some of the places in living organisms where they are found. Moving forwards, the students are challenged to recall the structure of the carbohydrates from topics 1.12 & 1.13 so that the structure of a triglyceride can be introduced. Students will learn that this macromolecule is formed from one glycerol molecule and three fatty acids and have to use their understanding of condensation reactions to draw the final structure. Time is taken to look at the difference in structure and properties of saturated and unsaturated fatty acids and students will be able to identify one from the other when presented with a molecular formula. The final part of the lesson explores how the various properties of a triglyceride mean that it has numerous roles in organisms including that of an energy store and source and as an insulator of heat and electricity.

This lesson describes the synthesis and breakdown of disaccharides by the formation or breakage of glycosidic bonds during condensation and hydrolysis reactions. The PowerPoint and accompanying question sheet have been designed to cover specification points 2.2 © & (d) of the CIE International A-level Biology course and also considers how these glycosidic bonds have to be broken in the non-reducing sugar test The first section of the lesson focuses on a prefix and a suffix so that the students can recall that the names of the common disaccharides end in -ose. In line with this, a quick quiz round is used to introduce maltose, sucrose and lactose before students are challenged on their prior knowledge of the structure of alpha glucose and then guided to draw maltose. Students are then given the opportunity to study the displayed formula of galactose, fructose, deoxyribose and ribose before being shown sucrose and lactose and being challenged to recognise the monosaccharides involved in the synthesis of each one. Time is taken to demonstrate how their knowledge of these disaccharides will be important in later topics such as extracellular enzymes, translocation in the phloem and the Lac Operon in the control of gene expression. The next task involves two exam-style questions where students have to demonstrate and apply their newly acquired knowledge by answering questions about two unfamiliar disaccharides. The final section of the lesson looks at the test for a non-reducing sugar like sucrose and the need to begin with the breaking of the glycosidic bond to “free up” the reducing sugars

This fully-resourced lesson describes the relationship between the molecular structure of a triglyceride and its functions in living organisms. The engaging PowerPoint and accompanying worksheets have been designed to cover specification point 2.2 (f) of the CIE International A-level Biology course and links are also made to related future topics such as the importance of the myelin sheath for the conduction of an electrical impulse and the use of lipids as a respiratory substrate. The lesson begins with a focus on the basic structure and roles of lipids, including the elements that are found in this biological molecule and some of the places in living organisms where they are found. Moving forwards, the students are challenged to recall the structure of the carbohydrates from earlier in topic 2 so that the structure of a triglyceride can be introduced. Students will learn that this macromolecule is formed from one glycerol molecule and three fatty acids and have to use their understanding of condensation reactions to draw the final structure. Time is taken to look at the difference in structure and properties of saturated and unsaturated fatty acids and students will be able to identify one from the other when presented with a molecular formula. The final part of the lesson explores how the various properties of a triglyceride mean that it has numerous roles in organisms including that of an energy store and source and as an insulator of heat and electricity.

Simple and facilitated diffusion are forms of passive transport and this lesson describes the factors that increase the rate of this movement across membranes. This fully-resourced lesson is the first in a series of two that have been designed to cover specification point 2.4 of the Pearson Edexcel A-level Biology A and the involvement of channel and carrier proteins is also described and discussed. In a number of previous lessons that covered specification points 2.1 and 2.2, students were provided with the details of gas exchange surfaces and the structure and properties of cell membranes. This lesson continually refers back to the content of these lessons so that links can be made between the movement across a cell membrane with the concentration gradient, the parts of the membrane involved and any features that may increase the rate at which the molecules move. A series of questions about the alveoli is 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. The other lesson included in this series to cover specification point 2.4 describes active transport, endocytosis and exocytosis.

This engaging lesson describes how chromosome mutations result in changes to the number or structure of chromosomes and focuses on Downs and Turner’s syndrome. The PowerPoint and accompanying resources have been designed to cover specification points 2.3 (vi) and (vii) as detailed in the Edexcel A-level Biology B specification. A human karyotype which has not been altered by a mutation is studied at the start of the lesson to allow students to recall the usual number of chromosomes as well as the sex chromosomes. They are then challenged to identify the differences when presented with the karyotypes of sufferers of Downs, Turner’s and Klinefelter’s syndrome. Students will learn that in the majority of cases, these conditions are the result of non-disjunction and having been assisted in the explanation of the outcome for Downs and Klinefelters, they have to form their own for Turner’s. The remainder of the lesson looks at other types of mutations, including translocation, and students will also see how whole sets of chromosomes can be duplicated in polyploidy.

This revision resource contains a concise yet informative PowerPoint (25 slides) and a worksheet that will enable the students to assess their understanding of the topic B4 (Enzymes) content of the CIE IGCSE Combined Science specification for examination in June and November 2020 and 2021. The range of exam questions (with explained answers), quick tasks and quiz competitions have been designed to cover as much content as possible but the following topics have received particular attention: Enzymes as biological catalysts that speed up reactions The binding of a substrate with the active site of an enzyme The effect of a changing pH on the activity of an enzyme The effect of a changing temperature on the activity of an enzyme Denaturation

This concise, engaging revision lesson has been designed to include activities that will motivate the students whilst they assess their understanding of topic B3 (Biological molecules) of the CIE IGCSE Combined Science specification. An understanding of biological molecules is fundamental to the understanding of a lot other Biology topics and this lesson has attempted to make the links between the different areas. The range of activities which include exam questions, quick tasks and quiz competitions have been written to cover as much of the content as possible but the following topics have received particular attention: The chemical elements in carbohydrates The formation of starch and glycogen from glucose The iodine test for starch Lipids are formed of fatty acids and glycerol Investigational skills The ethanol emulsion test for lipids This resource includes a PowerPoint (27 slides) and a worksheet with a task about the digestion of milk fat so students can recognise the components of lipids

This engaging lesson acts as an introduction to carbohydrates and describes the differences between monosaccharides, disaccharides and polysaccharides. The PowerPoint and accompanying worksheet have been designed to cover the first part of points 1.12 & 1.13 of the Pearson Edexcel A-level Biology A specification and make clear links to the upcoming lessons in this sub-topic on these three main groups of carbohydrates. The lesson begins with a made-up round of the quiz show POINTLESS, where students have to try to identify four answers to do with carbohydrates. In doing so, they will learn or recall that these molecules are made from carbon, hydrogen and oxygen, that they are a source of energy which can sometimes be rightly or wrongly associated with obesity and that the names of the three main groups is derived from the Greek word sakkharon. A number of quick quiz rounds have been written into the lesson to introduce key terms in a fun and memorable way and the first round allows the students to meet some of common monosaccharides. Moving forwards, students will learn that a disaccharide is formed when two of these monomers are joined together and they are then challenged on their knowledge of condensation reactions which were originally encountered during the lesson on water. Students will understand how multiple reactions and multiple glycosidic bonds will result in the formation of a polysaccharide and glycogen and starch are introduced as well as amylose and amylopectin as components of this latter polymer. The final part of the lesson considers how hydrolysis reactions allow polysaccharides and disaccharides to be broken back down into monosaccharides.

This lesson reminds students of the meaning of homeostasis and describes the how thermoregulation maintains the body in dynamic equilibrium during exercise. The PowerPoint has been designed to cover point 7.17 of the Edexcel International A-level Biology specification. Students were introduced to homeostasis at GCSE and this lesson has been written to build on that knowledge and to add the key detail needed at this level. Focusing on the three main parts of a homeostatic control system, the students will learn about the role of the internal and peripheral thermoreceptors, the thermoregulatory centre in the hypothalamus and the range of effectors which bring about the responses to restore optimum levels. The following responses are covered in this lesson: Vasodilation Increased sweating Body hairs In each case, time is taken to challenge students on their ability to make links to related topics such as the arterioles involved in the redistribution of blood and the high specific latent heat of vaporisation of water.

This lesson describes how the empirical formula of a compound can be deduced from the masses of the different parts. The PowerPoint and accompanying resources have been designed to cover points 1.44 & 1.45 of the Edexcel GCSE Chemistry specification and also covers those points in the Chemistry section of the Combined Science course. This lesson uses a step-by-step guide to walk students through the method involved in calculating the empirical formula. Students are given a template to use as they are introduced to the questions and then encouraged to work without it as the lesson progresses. The students are shown how empirical formula questions can be made more difficult and hints are given so that students are able to tackle them and access all of the marks available.