This fully-resourced lesson guides students through the use of the Hardy-Weinberg equation to see whether a change in allele frequency is occurring in a population over time. The detailed PowerPoint and differentiated practice questions worksheets have been designed to cover point 4.5 (i) of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification which expects students to be able to use this mathematical equation The lesson begins by looking at the equation and ensuring that 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 fully-resourced lesson looks at how errors in DNA replication can give rise to gene mutations and then links to an earlier topic by exploring how these base changes can affect the primary structure of a polypeptide. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 2.12 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification and constantly refers back to points 2.7, 2.8 and 2.9 which detail the genetic code, genes and the structure of proteins. In order to understand how a change in the base sequence can affect the order of the amino acids, students must be confident in their understanding and application of protein synthesis which was taught in 2.6. Therefore, the start of the lesson focuses on transcription and translation and students are guided through the use of the codon table to identify amino acids. Moving forwards, a quick quiz competition is used to introduce the names of three types of gene mutation whilst challenging the students to recognise terms which are associated with the genetic code and were met in the previous lesson. The main focus of the lesson is base substitutions and how these mutations may or may not cause a change to the amino acid sequence. The students are challenged to use their knowledge of the degenerate nature of the genetic code to explain how a silent mutation can result. The rest of the lesson looks at base deletions and base insertions and students are introduced to the idea of a frameshift mutation. One particular task challenges the students to evaluate the statement that base deletions have a bigger impact on primary structure than base substitutions. This is a differentiated task and they have to compare the fact that the reading frame is shifted by a deletion against the change in a single base by a substitution.

This fully-resourced lesson looks at the series of oxidation-reduction reactions that form the Krebs cycle and focuses on the products in terms of reduced NAD, FAD and ATP. The engaging PowerPoint and accompanying resource have both been designed to cover the fifth part of point 5.2 of the AQA A-level Biology specification. The lesson begins with a version of the Impossible game where students have to spot the connection between 8 of the 9 terms and will ultimately learn that this next stage is called the Krebs cycle. The main part of the lesson challenges the students to use descriptions of the main steps of the cycle to continue their diagram of the reactions. Students are continually exposed to key terminology such as decarboxylation and dehydrogenation and they will learn where carbon dioxide is lost and reduced NAD and FAD are generated. They will also recognise that ATP is synthesised by substrate level phosphorylation. The final task challenges them to apply their knowledge of the cycle to work out the numbers of the different products and to calculate the number of ATP that must be produced in the next stage This lesson has been designed to tie in with the other uploaded lessons on glycolysis, anaerobic respiration, the Link reaction and oxidative phosphorylation.

This detailed lesson introduces the four stages of aerobic respiration and looks at the relationship between structure and function of the mitochondrion. The engaging PowerPoint and accompanying resource have been designed to cover points 12.2 (a) and (i) of the CIE International A-level Biology specification which states that students should be able to demonstrate and apply an understanding of the inner and outer mitochondrial membranes, cristae, matrix and mitochondrial DNA. The lesson begins with an introduction to glycolysis and students will learn how this first stage of aerobic respiration is also the first stage when oxygen isn’t present. A version of “GUESS WHO” challenges students to use a series of structural clues to whittle the 6 organelles down to just the mitochondrion so that they can learn how the other three stages take place inside this organelle. Moving forwards, the key components of the organelle are identified on a diagram. Students are introduced to the stages of respiration so that they can make a link to the parts of the cell and the mitochondria where each stage occurs. Students will learn that the presence of decarboxylase and dehydrogenase enzymes in the matrix along with coenzymes and oxaloacetate allows the Link reaction and the Krebs cycle to run. Finally, time is taken to introduce the electron transport chain and the enzyme, ATP synthase, so that students can begin to understand how the flow of protons across the inner membrane results in the production of ATP.

This clear and concise lesson looks at the role of the link reaction in the conversion of pyruvate to acetyl coenzyme A which will then enter the Krebs cycle. The PowerPoint has been designed to cover point 12.2 © of the CIE International A-level Biology specification which states that students should be able to explain that this conversion occurs in the matrix when oxygen is present The lesson begins with a challenge, where the students have to recall the details of glycolysis in order to form the word matrix. This introduces the key point that this stage occurs in this part of the mitochondria and time is taken to explain why the reactions occur in the matrix as opposed to the cytoplasm like glycolysis. Moving forwards, the link reaction is covered in 5 detailed bullet points and students have to add the key information to these points using their prior knowledge as well as knowledge provided in terms of NAD. The students will recognise that this reaction occurs twice per molecule of glucose and a quick quiz competition is used to test their understanding of the numbers of the different products of this stage. This is just one of the range of methods that are used to check understanding and all answers are explained to allow students to assess their progress. This lesson has been written to tie in with the other uploaded lessons on glycolysis and the Krebs cycle and oxidative phosphorylation.

This fully-resourced lesson explores how glucose as well as the other respiratory substrates, such as lipids and proteins, can enter the respiratory pathway and therefore can be respired to produce molecules of ATP. The engaging PowerPoint and accompanying resources have been designed to cover points 12.1 (f) and (g) of the CIE International A-level Biology specification which states that students should be able to explain the relative energy values of carbohydrates, lipids and proteins and be able to determine respiratory quotients from equations. This lesson has been written to challenge current understanding as well as introduce details of glycolysis, the link reaction and Krebs cycle as these stages have yet to be covered fully. Students will learn that lipids and proteins can be used as respiratory substrates and will recognise the different ways that they enter the respiratory pathway. A quick quiz competition is used to introduce the relative energy value for carbohydrates and students are challenged to predict how the values for lipids and proteins will compare. As a result, students will recognise that a greater number of hydrogen atoms results in a greater availability of protons to form the proton gradient to fuel the production of ATP. The rest of the lesson focuses on the calculation of the respiratory quotient and time is taken to look at how the result can be interpreted to determine which substrates were respired.

This fully-resourced lesson explores how the structure of arteries, veins and capillaries relates to their functions. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 1.3 of the Pearson Edexcel A-level Biology A (Salters Nuffield) specification. This lesson has been written to build on any prior knowledge from GCSE or earlier in this topic to enable students to fully understand why a particular type of blood vessel has particular features. Students will be able to make the connection between the narrow lumen and elastic tissue in the walls of arteries and the need to maintain the high pressure of the blood. A quick version of the GUESS WHO game is used to introduce smooth muscle and collagen in the tunica media and externa and again the reason for their presence is explored and explained. Moving forwards, the lesson considers the structure of the veins and students are challenged to explain how the differences to those observed in arteries is due to the lower blood pressure found in these vessels. The final part of the lesson looks at the role of the capillaries in exchange. Links are made to diffusion to ensure that students can explain how the red blood cells pressing against the endothelium results in a short diffusion distance. It is estimated that it will take about 2 hours of allocated A-level Biology teaching time to cover the detail included in this lesson

This detailed lesson describes and explains the blood pressure changes that occur during systole and diastole of the cardiac cycle. The PowerPoint and accompanying resource have been designed to cover point 8.2 © of the CIE International A-level Biology specification. The start of the lesson introduces the cardiac cycle as well as the key term systole, so that students can immediately recognise that the three stages of the cycle are atrial and ventricular systole followed by diastole. Students are challenged on their prior knowledge of the structure of the heart as they have to name and state the function of an atrioventricular and semi-lunar valve from an internal diagram. This leads into the key point that pressure changes in the chambers and the major arteries results in the opening and closing of these sets of valves. Students are given a description of the pressure change that results in the opening of the AV valves and shown where this would be found on the graph detailing the pressure changes of the cardiac cycle. They then have to use this as a guide to write descriptions for the closing of the AV valve and the opening and closing of the semi-lunar valves and to locate these on the graph. By providing the students with this graph, the rest of the lesson can focus on explaining how these changes come about. Students have to use their current and prior knowledge of the chambers and blood vessels to write 4 descriptions that cover the cardiac cycle. The final part of the lesson covers the changes in the volume of the ventricle. This lesson has been written to tie in with the other uploaded lessons on the heart as detailed in topic 8.2

This lesson focuses on the structure of RNA and specifically the similarities and differences between this nucleic acid and DNA. The engaging and detailed PowerPoint and accompanying resource have been designed to cover the second part of point 6.1 (b) of the CIE International A-level Biology specification which states that students should be able to describe the structure of this nucleic acid. Students were introduced to the detailed structure of a nucleotide and DNA in previous lessons, so this lesson is written to tie in with those and continuously challenge prior knowledge as well as the understanding of the current topic. The lesson begins with the introduction of RNA as a member of the family of nucleic acids and this enables students to recognise that this polynuclotide shares a number of structural features that were previously seen in DNA. A quiz round called “A FAMILY AFFAIR” is used to challenge their knowledge of DNA to recognise those features that are also found on RNA such as the chain of linked nucleotides, pentose sugars, nitrogenous bases and phosphodiester bonds. The next task pushes them to consider features that have not been mentioned and therefore are differences as they answer a structured exam-style question on how RNA differs from DNA. Students will learn that RNA is shorter than DNA and this leads into the final part of the lesson where mRNA and tRNA are introduced and again they are challenged to use the new information explain the difference in size. Brief details of transcription and then translation are provided so that students are prepared for the upcoming lessons on protein synthesis

This lesson looks at the detailed structure of DNA and builds on the knowledge from topic 1 to explain how this nucleic acid differs in the nucleus, mitochondria and chloroplasts of eukaryotic cells and in prokaryotic cells. Both the engaging PowerPoint and accompanying resources have been designed to cover the first part of point 6.1 (b) of the CIE International A-level Biology specification. As well as focusing on the differences between the DNA found in these two types of cells which includes the length, shape and association with histones, the various tasks will ensure that students are confident to describe how this double-stranded polynucleotide is held together by hydrogen and phosphodiester bonds. These tasks include exam-style questions which challenge the application of knowledge as well as a few quiz competitions to maintain engagement.

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 point 6.2 (a) of the CIE International A-level Biology specification which states that students should understand how a gene codes for a polypeptide. 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 CIE 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 which forms a link to an upcoming lesson on gene mutations.

This detailed lesson describes the role of the mRNA, tRNA, amino acids and the ribosome during the second stage of protein synthesis - translation. Both the PowerPoint and accompanying resources have been designed to cover the third part of point 4.2 of the AQA A-level Biology specification and ties in with the previous lessons in this topic on RNA and transcription. Translation is a topic which is often poorly understood and so this lesson has been written to enable the students to understand how to answer the different types of questions by knowing and including the key details of the structures involved. 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, the genetic code 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 that consists of this considerable 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 through the lesson, their confidence to answer this type 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 learnt to answer some questions which involve the genetic code and the mRNA codon table.

This detailed and engaging lesson looks at the culture of transformed host cells as an in vivo method to amplify DNA fragments. Both the PowerPoint and accompanying resources have been designed to cover the third part of point 8.4.1 of the AQA A-level Biology specification and ties in with the previous two lessons in this sub-topic on producing DNA fragments and the polymerase chain reaction. The lesson begins with the introduction of the terms transgenic and transformed. Students will learn that bacterial cells are the most commonly transformed cells so the next task challenges their recall of the structures of these cells so that plasmid DNA can be examined from that point onwards. A quick quiz competition is used to introduce the key term, vector, and then the rest of the lesson looks at the details of the five steps involved in the transformation of the host cell: Remove and prepare the plasmid to act as a vector Insert the DNA fragment into the vector Transfer the recombinant plasmid into the host cell Identify the cells which have taken up the recombinant plasmid All the transformed host cells to replicate and express the novel gene Time is taken to explore the finer details of each step such as the addition of the promoter and terminator regions, use of the same restriction enzyme to cut the plasmid as was used to cut the gene and the different types of marker genes. Links are continuously made to the previous lessons in this topic so that students feel confident to answer assessment questions which bring in knowledge from all of the sections.

This detailed lesson describes the structure of a nucleotide including the structure of the phosphorylated nucleotide, ATP. The engaging PowerPoint has been designed to cover point (a) of topic 6.1 as detailed in the CIE International A-level Biology specification and links are made throughout to earlier topics such as biological molecules as well as to upcoming topics like DNA structure and replication. Students were introduced to the term monomer and nucleotide in topic 2, so the start of the lesson challenges them to recognise this latter term when only the letters U, C and T are shown. This has been designed to initiate conversations about why only these letters were used so that the nitrogenous bases can be discussed later in greater detail. Moving forwards, students will learn that a nucleotide is the monomer to a polynucleotide and that deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are two examples of this type of polymer. The main part of the lesson has been filled with various tasks that explore the structural similarities and structural differences between DNA and RNA. This begins by describing the structure of a nucleotide as a phosphate group, a pentose sugar and a nitrogenous base. Time is taken to consider the details of each of these three components which includes the role of the phosphate group in the formation of a phosphodiester bond between adjacent nucleotides on the strand. At this point students are challenged on their understanding of condensation reactions and have to identify how the hydroxyl group associated with carbon 3 is involved along with the hydroxyl group of the phosphoric acid molecule. A number of quiz rounds are used during this lesson, as a way to introduce key terms in a fun and memorable way. One of these rounds introduces adenine and guanine as the purine bases and thymine, cytosine and uracil as the pyrimidine bases and the students are shown that their differing ring structures can be used to distinguish between them. The remainder of the lesson focuses on ATP as a phosphorylated nucleotide and links are made to the hydrolysis of this molecule for energy driven reactions in cells such as active transport

Disaccharides are formed from the condensation of two monosaccharides and this lesson describes the formation of maltose, sucrose and lactose. The PowerPoint and accompanying question sheet have been designed to cover the second part of point 1.2 of the AQA A-level Biology specification but also make links to the previous lesson on monosaccharides when considering the different components of these three disaccharides. The first section of the lesson focuses on a prefix and a suffix so that the students can recognise 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 as they have to describe how condensation reactions and the formation of glycosidic bonds were involved in the synthesis of each one. The main task of the lesson again challenges the students to recall details of a previous lesson as they have to identify the monomers of each disaccharide when presented with the displayed formula. Time is taken to show how their knowledge of these simple sugars will be important in later topics such as digestion, translocation in the phloem and the Lac Operon in the control of gene expression. The lesson finishes with two exam-style questions where students have to demonstrate and apply their newly acquired knowledge

This detailed and engaging lesson describes the basic structure of a mononucleotide and the similarities and differences between DNA and RNA. The PowerPoint and accompanying worksheet containing exam-style questions have been designed to cover points 2.5 (i) & (ii) of the Pearson Edexcel A-level Biology A specification. In topic 1, the students were introduced to a number of monomers and the start of the lesson challenges them to recognise the key term nucleotide when only the letters U, C and T are shown. The next part of the lesson describes the structure of a DNA nucleotide and an RNA nucleotide so that the pentose sugar and the bases adenine, cytosine and guanine can be recognised as similarities whilst deoxyribose and ribose and thymine and uracil are seen as the differences. Time is taken to discuss how a phosphodiester bond is formed between adjacent nucleotides and their prior knowledge and understanding of condensation reactions is tested through a series of questions. Students are then introduced to the purine and pyrimidine bases and this leads into the description of the double-helical structure of DNA and the hydrogen bonds between complementary bases. The final section of the lesson describes the structure of mRNA, tRNA and rRNA and students are challenged to explain why this single stranded polynucleotide is shorter than DNA In addition to the current understanding and prior knowledge checks, a number of quiz rounds have been written into the lesson to introduce key terms in a fun and memorable way and the final round acts as a final check on the structures of DNA and RNA.

This fully-resourced lesson describes the relationship between the structure, properties and functions of triglycerides in living organisms. The engaging PowerPoint and accompanying worksheets have been designed to be the first lesson in a series of two that cover specification points 2.1.2 (h), (i) & (j) of the OCR A-level Biology A course and the lesson contains numerous references to relevant 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 earlier in the sub-module 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.