This fully-resourced lesson looks at the effects of nervous mechanisms on the heart rate. The engaging and detailed PowerPoint and accompanying resources have been designed to cover the part of point 5.1.5 (k) of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply their knowledge and understanding of the control of the heart rate by the cardiovascular centre in the medulla oblongata This lesson begins with a prior knowledge check where students have to identify and correct any errors in a passage about the conduction system of the heart. This allows the SAN to be recalled as this structure play an important role as the effector in this control system. Moving forwards, the three key parts of a control system are recalled as the next part of the lesson will specifically look at the range of sensory receptors, the coordination centre and the effector. Students are introduced to chemoreceptors and baroreceptors and time is taken to ensure that the understanding of the stimuli detected by these receptors is complete and that they recognise the result is the conduction of an impulse along a neurone to the brain. A quick quiz is used to introduce the medulla oblongata as the location of the cardiovascular centre. The communication between this centre and the SAN through the autonomic nervous system can be poorly understood so detailed explanations are provided and the sympathetic and parasympathetic divisions compared. The final task challenges the students to demonstrate and apply their understanding by writing a detailed description of the control and this task has been differentiated three ways to allow differing abilities to access the work

This is an engaging and informative lesson that looks at the meaning of excretion in detail and explores the functions of the organs involved with the excretion of carbon dioxide and urea. This lesson has been designed for students studying A-level Biology. The lesson begins by introducing the definition of excretion to the students so that they are able to recognise that the substances being removed have to have come from a metabolic process in order to be excreted. This important difference to egestion (elimination) is a key detail which they need to understand at this level. Moving forwards, a quick competition is used to meet some of the organs that are involved in excretion. The remainder of the lesson focuses on the excretion of carbon dioxide. Links are made to the transport of carbon dioxide as hydrogen carbonate ions and how the affinity of haemoglobin for oxygen is affected when the carbon dioxide concentration is high. Students will meet the idea of deamination and the ornithine cycle and the key details of these two processes are covered. Progress checks have been written into this lesson at regular intervals, which challenge the students on knowledge from this lesson and prior knowledge, to enable them to constantly assess their understanding.

This is an engaging lesson that looks at the structures and actions of the two parts of the autonomic nervous system (ANS) and shows students where this particular system fits into the whole organisation of the nervous system. The lesson begins by introducing the students to the idea that motor neurones are not simply somatic motor neurones but will actually be classified as autonomic motor neurones if they innervate the involuntary muscles. A range of tasks, progress checks and quick competitions are used during the lesson to engage the students in this topic and show them how it relates to other topics such as motor neurones and neurotransmitters. Key terminology is used throughout, such as ganglions, so that students can recognise and access the marks if an exam question on this topic arises. This lesson has been written for A-level students

This is a fast-paced lesson that explores the structural differences (and similarities) between sensory and motor neurones. The lesson uses a range of tasks, progress checks and quick competitions to enable the students to recognise how these neurones differ in terms of the cell body, axon and dendron. Students will also understand that both neurones are myelinated which allows saltatory conduction to occur. Relay neurones are briefly discussed during the final section of the lesson. This lesson has primarily been designed for A-level students but can be used with the content means that it is suitable for use with GCSE students too who are studying the nervous system.

This fully-resourced lesson explores how the structure of arteries, arterioles, capillaries, venules and veins relate to their functions. The engaging and detailed PowerPoint and accompanying resources have been designed to cover point 3.1.2 © of the OCR A-level Biology A 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, it is quite likely that some students will not be aware of the transition vessels that are the arterioles. This section begins with an understanding of the need for these vessels because the structural and functional differences between arteries and capillaries is too significant. The action of the smooth muscle in the walls of these vessels is discussed and students will be challenged to describe a number of situations that would require blood to be redistributed. The middle part of the lesson looks at the role of the capillaries in exchange and 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. The remainder of 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. It is estimated that it will take at least 2 hours of allocated A-level Biology teaching time to cover the detail included in this lesson

This is a fully-resourced lesson that looks at the functional and structural differences between the transport tissues in a plant, the xylem and phloem. The lesson includes an engaging lesson presentation (41 slides), which includes numerous student-led tasks, progress checks and quick competitions and two question worksheets, one of which is a differentiated version to enable those students who are finding this topic difficult to still be able to access the learning. The lesson begins with the introduction of the two tissues as well as a brief introduction to the substances which they each carry. The next part of the lesson focuses on the xylem cells and the resulting xylem vessel, and key terms such as lignin are brought into the lesson so that students can understand how these cells are waterproofed, which causes them to decay and form hollow tubes. Having met a lot of information, students are challenged to act like an examiner to form a table based question to compare the xylem against the phloem where they have to come up with features which could be compared against. This table will form the backbone of the lesson and students will use it later in the lesson when they have to write summary passages about each of the tissues. Moving forwards, a quick competition is used to enable the students to meet the names of the cells that form the phloem tissue, the sieve tube elements and the companion cells. Students will see how they are involved in the functioning of the phloem and questions are posed which relate to other topics such as the involvement of mitochondria wherever active transport occurs. Progress checks like this are found at regular intervals throughout the lesson so that students can constantly assess their understanding. This lesson has been designed for GCSE students. If you are looking to teach about these tissues but to a higher standard, you could use my uploaded alternative called Xylem and Phloem (A-level)

This fully-resourced lesson explains how gel electrophoresis is used to separate DNA fragments or proteins and explores its applications in genetic fingerprinting. The engaging and detailed PowerPoint and accompanying resources have been written to cover point 6.1.3 (e) of the OCR A-level Biology A specification The steps of the genetic fingerprinting process is covered the whole lesson but the main focus is the use of gel electrophoresis within this process. Students will be introduced to STRs and will come to recognise their usefulness in human identification as a result of the variability between individuals. Moving forwards, the involvement of the PCR is discussed and students are challenged on their knowledge of this process as it was encountered in a previous lesson. A brief outline of the role of restriction enzymes is provided to support students when these key gene technology enzymes are met in more detail later in the module. The main section of the lesson focuses on the use of gel electrophoresis to separate DNA fragments (as well as proteins) and the key ideas of separation due to differences in base pair length or molecular mass are discussed and explained. As well as current understanding checks, an application question involving Huntington’s disease is used to challenge their ability to apply their knowledge of the process to an unfamiliar situation. The remainder of the lesson describes how the DNA is transferred to a membrane and hybridisation probes are used to create a pattern on the X-ray film. Time has been taken to make continuous links to the previous lessons in module 6.1.3 as well as those from module 2.1.3 where DNA, RNA and protein synthesis were introduced.

This lesson describes the active loading of assimilates like sucrose at the source and the translocation along the phloem to the sink. Both the detailed PowerPoint and accompanying resources have been designed to cover point 3.1.3 (f) of the OCR A-level Biology A specification. The lesson begins by challenging the students to recognise the key term translocation when it is partially revealed and then the rest of the lesson focuses on getting them to understand how this process involves the mass flow of assimilates down the hydrostatic pressure gradient from the source to the sink. It has been written to tie in with 3.1.3 (b) where the structure of the phloem tissue was initially introduced and the students are continually challenged on this prior knowledge. A step-by-step guide is used to describe how sucrose is loaded into the phloem at the source by the companion cells. Time is taken to discuss key details such as the proton pumping to create the proton gradient and the subsequent movement back into the cells by facilitated diffusion using co-transporter proteins. Students will learn that the hydrostatic pressure at the source is high, due to the presence of the water and sucrose as cell sap, and that this difference when compared to the lower pressure at the sink leads to the movement along the phloem. A number of quick quiz rounds are included in the lesson to maintain engagement and to introduce key terms and the lesson concludes with a game of SOURCE or SINK as students have to identify whether a particular plant structure is one or the other (or both)

This extensive and fully-resourced lesson describes the principles and explains the techniques used in the production of recombinant DNA in genetic engineering. Both the engaging PowerPoint and accompanying resources have been written to cover points 6.1.3 (f) (i & ii) of the OCR A-level Biology A specification. The lesson begins with a definition of genetic engineering and recombinant DNA to allow students to begin to understand how this process involves the transfer of DNA fragments from one species to another. Links are made to the genetic code and transcription and translation mechanisms, which were met in module 2, in order to explain how the transferred gene can be translated in the transgenic organism. Moving forwards, the method involving reverse transcriptase and DNA polymerase is introduced and their knowledge of the structure of the polynucleotides and the roles of enzymes is challenged through questions and discussion points. Restriction enzymes are then introduced and time is taken to look at the structure of a restriction site as well as the production of sticky ends due to the staggered cut on the DNA. A series of exam-style questions with displayed mark schemes are used to allow the students to assess their current understanding. The second half of the lesson looks at the culture of transformed host cells as an in vivo method to amplify DNA fragments. 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. The following key steps are described and explained: • 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 • Allow 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. As well as understanding and prior knowledge checks, quick quiz competitions are used throughout the lesson to introduce key terms such as cDNA and EcoR1 in a memorable way.

This fully-resourced lesson explores how the presence of particular alleles at one locus can mask the expression of alleles at a second locus in epistasis. The detailed and engaging PowerPoint and associated resources have been designed to cover the part of point 6.1.2 (b[ii]) of the OCR A-level Biology A specification which states that students should be able to demonstrate and apply their knowledge and understanding of the use of phenotypic ratios to identify epistasis. This is a topic which students tend to find difficult, and therefore the lesson was written to split the topic into small chunks where examples of dominant, recessive and complimentary epistasis are considered, discussed at length and then explained. Understanding checks, in various forms, are included throughout the lesson so that students can assess their progress and any misconceptions are immediately addressed. There are regular links to related topics such as dihybrid inheritance so that students can meet the challenge of interpreting genotypes as well as recognising the different types of epistasis.

This is an informative lesson that builds on the knowledge that students gained at GCSE on the topic of inheritance to enable them to carry out genetic crosses for the inheritance of a single gene at A-level. The start of the lesson focuses on the terminology that is associated with this topic which has to be recognised and understood if students are going to be able to begin a cross. Time is taken to go over key points such as the genotypes and working out the different possible gametes that would be produced by meiosis. Students can save time by only showing the different gametes so assistance is given on this. As can be seen from the cover image, a step by step guide is used to go through a number of examples so that students can visualise how to set out their diagrams in order to maximise the marks gained. There are progress checks written into the lesson throughout so that assessment is constant. This lesson can be taught alongside another upload called “understanding genetic trees”

This engaging lesson looks at the role of haemoglobin in transporting oxygen and carbon dioxide and compares the dissociation curves for foetal and adult haemoglobin. The detailed PowerPoint has been designed to cover points 3.1.2 (i & j) of the OCR A-level Biology A specification and includes references to the role of carbonic anhydrase and the formation of haemoglobinic acid and carbaminohaemoglobin. The lesson begins with a version of the quiz show Pointless to introduce haemotology as the study of the blood conditions. Students are told that haemoglobin has a quaternary structure and are challenged to use their prior knowledge of biological molecules to determine what this means for the protein. They will learn that each of the 4 polypeptide chains contains a haem group with an iron ion attached and that it is this group which has a high affinity for oxygen. Time is taken to discuss how this protein must be able to load (and unload) oxygen as well as transport the molecules to the respiring tissues. Students will plot the oxyhaemoglobin dissociation curve and the S-shaped curve is used to encourage discussions about the ease with which haemoglobin loads each molecule. At this point, foetal haemoglobin and its differing affinity of oxygen is introduced and students are challenged to predict whether this affinity will be higher or lower than adult haemoglobin and to represent this on their dissociation curve. The remainder of the lesson looks at the different ways that carbon dioxide is transported around the body that involve haemoglobin. Time is taken to look at the dissociation of carbonic acid into hydrogen ions so that students can understand how this will affect the affinity of haemoglobin for oxygen in an upcoming lesson on the Bohr effect. It is estimated that it will take in excess of 2 hours of A-level teaching time to cover the detail of these two specification points as covered in this lesson

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