This fully-resourced lesson describes the effects of enzyme and substrate concentration on enzyme activity. The PowerPoint and accompanying resources are the third in a series of 3 lessons which cover the details of point 2.1.4 (d) [i] of the OCR A-level Biology A specification and students are also challenged on their recall of the details of transcription and translation as covered in module 2.1.3. The first part of the lesson describes how an increase in substrate concentration will affect the rate of reaction when a fixed concentration of enzyme is used. Time is taken to introduce limiting factors and students will be challenged to identify substrate concentration as the limiting factor before the maximum rate is attained and then they are given discussion time to identify the possible factors after this point. A series of exam-style questions are used throughout the lesson and the mark schemes are displayed to allow the students to assess their understanding and for any misconceptions to be immediately addressed. Moving forwards, the students have to use their knowledge of substrate concentration to construct a graph to represent the relationship between enzyme concentration and rate of reaction and they have to explain the different sections of the graph and identify the limiting factors. The final section of the lesson describes how the availability of enzymes is controlled in living organisms. Students will come to recognise that this availability is the result of enzyme synthesis and enzyme degradation and a SPOT THE ERRORS task is used to challenge their recall of protein synthesis. Please note that this lesson explains the Biology behind the effect of concentration on enzyme activity and not the methodology involved in carrying out such an investigation as this is covered in the lessons designed in line with point 2.1.4 (d) [ii]

This engaging lesson explains why coenzymes, cofactors and prosthetic groups are needed in some enzyme-controlled reactions. The PowerPoint and accompanying resource have been primarily designed to cover point 2.1.4 (e) of the OCR A-level Biology specification but can also be used as a revision lesson for the roles of ions as was covered back in module 2.1.2. The lesson begins with an introduction of the description of a cofactor and students will learn that some are permanently bound to the enzyme whilst others only form temporary associations. A quick quiz competition runs over the course of the lesson and is used to introduce prosthetic groups, mineral ion cofactors and organic coenzymes and zinc ions with carbonic anhydrase, chloride ions with amylase and NAD are used as examples of each type. The lesson has been planned to make links to related topics such as cations, anions, transport of carbon dioxide and respiration which will test students on their prior knowledge as well as prepare them for these topics in modules 3 and 5.

This fully-resourced lesson describes the primary non-specific defences against pathogens in animals. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 4.1.1 (d) of the OCR A-level Biology A specification and describes the following defences: skin key steps of the blood clotting process release of histamine in the inflammatory response expulsive reflexes mucous membranes There are clear links to topics in modules 2 and 3 in each of these defences so time is taken to consider these during the descriptions. For example, the presence of keratin in the cytoplasm of the skin cells allows the student knowledge of the properties of this fibrous protein to be checked. Other topics that are revisited during this lesson include protein structure, formation of tissue fluid, key terminology and roles of inorganic ions in biological processes. There is also a section of the lesson which refers to the genetics behind haemophilia and students are challenged to apply knowledge to an unfamiliar situation. This will prepare them for this topic when covered in module 6.1.2 All of the exam-style questions and tasks have mark schemes that are embedded in the PowerPoint and a number of them have been differentiated to allow students of differing abilities to access the work.

This fully-resourced lesson describes the main stages of mitosis and explains the significance of this type of nuclear division in life cycles. The PowerPoint and accompanying resources have been designed to cover points 2.1.6 (c & e) of the OCR A-level Biology A specification and make direct links to the previous lesson which covered the cell cycle Depending upon the exam board taken at GCSE, the knowledge and understanding of mitosis will differ considerably between students and there may be a number of misconceptions. This was considered at all points during the planning of the lesson so that existing errors are addressed and key points are emphasised throughout. Their understanding of interphase is challenged at the start of the lesson to ensure that they realise that it is identical pairs of sister chromatids that enter the M phase. The main part of the lesson focuses on prophase, metaphase, anaphase and telophase and describes how the chromosomes behave in these stages. There is a focus on the centrioles and the spindle fibres that they produce which contract to drag one chromatid from each pair in opposite directions to the poles of the cell. The remainder of the lesson is a series of understanding and application questions where students have to identify the various roles of mitosis in living organisms as well as tackling a Maths in a Biology context question. The lesson concludes with a final quiz round of MITOSIS SNAP where they only shout out this word when a match is seen between the name of a phase, an event and a picture.

This lesson describes the main stages of meiosis, focusing on the events which contribute to genetic variation and explains its significance in life cycles. The detailed PowerPoint and accompanying resources have been designed to cover points 2.1.6 (f) & (g) of the OCR A-level Biology A specification and includes description of crossing over, independent assortment, independent segregation and the production of haploid gametes In order to understand how the events of meiosis like crossing over and independent assortment and independent segregation can lead to variation, students need to be clear in their understanding that DNA replication in interphase results in homologous chromosomes as pairs of sister chromatids. Therefore the beginning of the lesson focuses on the chromosomes in the parent cell and this first part of the cycle and students will be introduced to non-sister chromatids and the fact that they may contain different alleles which is important for the exchange that occurs during crossing over. Time is taken to go through this event in prophase I in a step by step guide so that the students can recognise that the result can be new combinations of alleles that were not present in the parent cell. Moving forwards, the lesson explores how the independent assortment and segregation of chromosomes and chromatids during metaphase I and II and anaphase I and II respectively results in genetically different gametes. The key events of all of the 8 phases are described and there is a focus on key terminology to ensure that students are able to describe genetic structures in the correct context. The final part of the lesson looks at the use of a mathematical expression to calculate the possible combinations of alleles in gametes as well as in a zygote following the random fertilisation of haploid gametes. Understanding and prior knowledge checks are interspersed throughout the lesson as well as a series of exam-style questions which challenge the students to apply their knowledge to potentially unfamiliar situations. This lesson has been specifically planned to lead on from the previous two lessons on the cell cycle and the main stages of mitosis and constant references are made throughout to encourage students to make links and also to highlight the differences between the two types of nuclear division

This lesson describes the processes that take place during interphase, mitosis and cytokinesis and outlines how checkpoints regulate the cell cycle. The PowerPoint and accompanying resources have been designed to cover points 2.1.6 (a & b) of the OCR A-level Biology specification and prepares the students for the upcoming lessons on the main stages of mitosis and its significance in life cycles The students were introduced to the cell cycle at GCSE so this lesson has been planned to build on that knowledge and to emphasise that the M phase which includes mitosis (nuclear division) only occupies a small part of the cycle. The students will learn that interphase is the main stage and that this is split into three phases, G1, S and G2. A range of tasks which include exam-style questions, guided discussion points and quick quiz competitions are used to introduce key terms and values and to describe the main processes that occur in a very specific order. There is also a focus on the checkpoints, such as the restriction point that occurs before the S phase to ensure that the cell is ready for DNA replication. Extra time is taken to ensure that key terminology is included and understood, such as sister chromatid and centromere, and this focus helps to show how it is possible for genetically identical daughter cells to be formed at the end of the cycle. Important details of mitosis are introduced so students are ready for the next lesson, before the differences in cytokinesis in animal and plant cells are described.

This lesson describes how the recent use of similarities in biological molecules and other genetic evidence has led to new classification systems. The PowerPoint and accompanying resources have been designed to cover point 4.2.2 [c] (i) of the OCR A-level Biology A specification and focuses on the introduction of the three-domain system following Carl Woese’s detailed study of the ribosomal RNA gene. 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 previous lesson, 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. Moving forwards, the rest of the lesson considers other molecules that can be compared between species for classification purposes and the primary structure of cytochrome is described and discussed. At this point in the lesson, the students are also tested on their knowledge of the nature of the genetic code and have to explain how mutations to DNA can also be used for comparative purposes.

This lesson describes how to calculate the standard deviation to measure the spread of a set of data and to compare means using the t-test. The detailed PowerPoint and accompanying resources have been designed to cover the part of point 4.2.2 (f) of the OCR A-level Biology A specification that includes these two statistical tests. 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 introduced and students will learn to accept or reject this based upon a comparison of their value against one taken from the table based on the degrees of freedom.

This lesson describes how to use the Spearman’s rank correlation coefficient to consider the relationship between two sets of data. The PowerPoint and accompanying exam-style question are part of the final lesson in a series of 3 which have been designed to cover point 4.2.2 (f) of the OCR A-level Biology A specification. The previous two lessons described the different types of variation and explained how to calculate the standard deviation and how to use the Student’s t-test to compare two means. As with the previous lesson, a step by step guide is used to walk the students through the use of the formula to generate the rank coefficient and to determine whether there is a positive correlation, no correlation or a negative correlation. The students are also reminded of the null hypothesis and will be shown how to accept or reject this hypothesis and to determine significance. The students will work through an example with the class and then are given the opportunity to apply their newly-acquired knowledge to an exam-style question. The mark scheme is displayed on the PowerPoint so they can assess their understanding

This detailed lesson looks at the structure of the mitochondrion and explains how the specific features allow the stages of aerobic respiration to take place in this organelle. The engaging PowerPoint and accompanying resource have been designed to cover point 5.2.2 (b) of the OCR A-level Biology A 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 a version of “GUESS WHO” where students have to use a series of structural clues to whittle the 6 organelles down to just 1 - the mitochondrion. 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 lesson has been designed to tie in with the other uploaded lessons on the stages of respiration.

A fully resourced revision lesson which uses a range of exam questions (with explained answers), quick tasks and quiz competitions to enable the students to assess their understanding of the topics found within module 3 (Exchange and transport) of the OCR A-level Biology specification. The topics tested within this lesson include: Exchange surfaces Mammalian gaseous exchange system Tissues in the gaseous exchange system Transport in animals Blood vessels Exchange at the capillaries ECG Transport of oxygen Transport in plants Transport tissues Movement of water through plants Transpiration Translocation Student will enjoy the range of tasks and quiz rounds whilst crucially being able to recognise any areas which require further attention