Scheme of Work AQA Biology Year 1 and AS (120 hours) One hour lessons Learning Outcomes Specification Content Skills Covered Student Book Section Required Practicals CHAPTER 1 – and Carbohydrates (11 Hours) 1 Biological Molecules Students can write on a sticky note a definition of an atom and a molecule to elicit discussion. Revisit previous learning using Molymods to show the difference between atoms and molecules. It may be useful to introduce concepts of relative scale and units of measurement at this point. Revisit and consolidate previous learning Ensure students are this is not examined content. 1.1 2 Biological Molecules Students to recall the definitions of monomers and polymers. Students could be asked to define these terms using less than 15 words. Students could clarify new ideas using interconnecting bricks or similar and to model monomers and polymers. Students to name the monomers found in living organisms and the polymers they build. Recall the definition for a monomer and polymer Describe the Biological Molecules as polymers and recall their monomers 3.1.1 Monomers and Polymers. Monomers are the smaller from which larger molecules are made. Polymers are molecules made from a number of monomers joined together. Monosaccharides, acids and nucleotides are examples of monomers. 1.1
You may wish to provide a circus task of activities to illustrate these properties including prompt questions e.g. Metabolite – students use Interconnecting bricks or similar to show polymerisation Solvent – dissolve sugar or salt in a beaker of water Heat Capacity – ice cubes and hot water into large beakers of room temperature water and measure temperature changes. Latent Heat – place a damp paper towel on the back of their hands Cohesion – use pipettes or straws to draw up water are important in biology. In particular, water: • is a metabolite in many metabolic reactions • is an important solvent • has a relatively high heat capacity • has a relatively large latent heat of vaporisation • has strong cohesion between water molecules 7 Water Students should be able to explain how the structure and bonding within and between water molecules provide its unique properties and how this is important to living cells. This is a good opportunity to practice exam technique by providing Students with a standardised sentence structure e.g. Water is/has ______ due to ____________ which provides cells with/allows cells to ________________ . Explain the function of water molecules within living organisms in relation to its structure and function 3.1.7 Water is a major component of cells. It has several properties that are important in biology. In particular, water: • is a metabolite in many metabolic reactions, including condensation and hydrolysis reactions • is an important solvent in which metabolic reactions occur • has a relatively high heat capacity, buffering changes in temperature • has a relatively large latent heat of vaporisation, providing a cooling effect with little loss of water through evaporation 1.2
Students should perform the tests for reducing and non-reducing sugars, be able to describe the method and results for the Biochemical tests and use them to correctly identify unknown substances. They can complete Assignment 3: Identifying Carbohydrates from Biochemical Tests. Biochemical tests using Benedict's solution for reducing sugars and non-reducing sugars and iodine/potassium iodide for starch. Students could use, and interpret the results of, qualitative tests for reducing sugars, sugars and starch. One hour lessons Learning Outcomes Specification Content Skills Covered Student Book Section Required Practicals CHAPTER 2 – Lipids and Proteins (9 hours) 1 Lipids - Triglycerides Students should recall that lipids are biological molecules containing C, H and O. They should recognise Triglycerides as a group of lipid formed by condensation reactions between glycerol and fatty acid chains and be able to draw and label this reaction and the formation of ester bonds. They may be able to synthesise diagrams of the hydrolysis reactions which break these molecules down. Students should recognise saturated, unsaturated and polyunsaturated fatty acids and describe the presence or absence of double bonds within them. Molymods can be used to make glycerol, Describe the structure of a triglyceride Describe, draw and label the condensation reactions required to form these molecules Describe how of a fatty acid maybe saturated or unsaturated 3.3.1 Lipids Triglycerides and phospholipids are two groups of lipid. Triglycerides are formed by the condensation of one molecule of glycerol and molecules of fatty acid. A condensation reaction between glycerol and a fatty acid (RCOOH) forms an ester bond. The R-group of a fatty acid may be saturated or unsaturated. Students should be able to: 2.1
etc. You could reiterate the idea that DNA provides the instructions for building these proteins. They could perform the biuret test. 5 Protein Structure Students should recall that amino acids are monomer units joined by a condensation reaction to form di/polypeptides with peptide bonds. They may be able to synthesis the hydrolysis reaction that breaks down these polymers. Students should be able to draw and label a standard amino acid and describe the primary, secondary, tertiary and quaternary structure of proteins. Molymods can be used to make amino acids, dipeptides and polypeptides. Recall the structure of an amino acid molecule Draw and the condensation reaction between two amino acids Describe the primary, secondary, tertiary and quaternary structure of polypeptides 3.1.4.1 General Properties of Proteins acids are the monomers from which proteins are made. The general structure of an amino acid. The twenty amino acids that are common in all organisms differ only in their side group. A condensation reaction between two acids forms a peptide bond. • Dipeptides are formed by the condensation of two amino acids. • Polypeptides are formed by the condensation of many amino acids. 2.2 6 Specific Shape of Proteins Students could complete Assignment 2: Identifying Amino Acids using Chromatography. Students should recognise how changing R groups influence protein shape through the role of hydrogen, ionic and disulfide bridge bonding. Explain how changing R groups contribute to the structure of a protein by altering bonding within the molecule 3.1.4.1 General Properties of Proteins Amino acids are the monomers from which proteins are made. The general structure of an amino acid. The twenty amino acids that are common in all organisms differ only in their side group. MS 0.3 MS2.4 PS2.3 PS3.3 AT g Students could use chromatography with known standard solutions, to separate a mixture of acids and identify their components 2.2
The role of hydrogen bonds, ionic bonds and disulfide bridges in the structure of proteins. 7 Protein Function Students should describe the structure and function of Fibrous and Globular proteins. You introduce some named examples i.e. Haemoglobin. Students could use modelling clay to make a model of a fibrous protein like collagen and a globular protein like haemoglobin. Describe the structure and function of proteins. 3.1.4.1 General Properties of Proteins A functional protein may contain one or more polypeptides. Proteins have a variety of functions within all living organisms. The relationship between primary, secondary, tertiary and quaternary structure, and protein function. 2.2 8 Consolidating learning Students can spend a lesson consolidating learning from the previous two chapters. They could play games like Taboo to cement learning of Key terms and produce revision resources such as cue cards and quick quizzes. They can complete the practice questions and peer mark with the mark scheme before correcting their work in order to develop exam technique. Mind maps can be produced to draw together all the concepts taught so far. Venn diagrams can be used to compare carbohydrates, lipids and proteins. Revisit and consolidate learning from Chapters 1 and 2 Identify of weakness which require further study Compare progress to MTG 9 Test/past papers Following on from the above, this lesson can be spent completing an AFL test consisting of past paper questions. This can be marked to Revisit and consolidate learning from Chapters 1 and 2 Identify areas of weakness which require further study
• The specificity of enzymes 3 How enzymes work Students should move on from the ‘lock and key’ model they worked with at GCSE and be able to describe the ‘induced fit’ model. There are several animations available on the internet to illustrate this concept. Students can make clay models to illustrate the lock and key and induced fit models. Describe the induced fit model of enzyme action 3.1.4.2 Many Proteins are Enzymes The induced-fit model of enzyme action. The properties of an enzyme relate to the tertiary structure of its active site and its ability to combine with complementary substrate(s) to form an complex. Students should be able to: • appreciate how models of enzyme action have changed over time 3.3 4 Factors effecting Enzyme function Focusing on enzyme and concentration. Students could complete a set of simple practical activities to illustrate such as oxygen produced from catalase (from potatoes) and different hydrogen peroxide concentrations. Describe the effects of concentration on enzyme activity 3.1.4.2 Many Proteins are Enzymes • The effects of the following factors on the rate of enzyme controlled reactions – enzyme concentration, concentration, concentration of competitive and of inhibitors, pH and temperature. 3.4 5 Factors effecting Enzyme function Focusing on temperature in preparation for required practical. You could show a piece of liver (catalase) catalysing the breakdown of hydrogen peroxide and then heat the liver in a Bunsen flame and repeat. Describe the effects of temperature on the activity of enzymes 3.1.4.2 Many Proteins are Enzymes • The effects of the following factors on the rate of enzyme controlled reactions – enzyme concentration, substrate concentration, concentration of competitive and of PS1.2 PS2.1 PS2.4 3.4
• The hydrolysis of ATP can be coupled to energy-requiring reactions within cells. • The inorganic phosphate released during the hydrolysis of ATP can be used to phosphorylate other compounds, often making them more reactive. ATP is re-synthesised by the condensation of ADP and Pi. This reaction is catalysed by the enzyme ATP synthase during photosynthesis, or during respiration. 8-10 Consolidating/revision In the first lesson Students can spend a lesson consolidating learning from the previous two chapters. They could play games like Taboo to cement learning of Key terms and produce revision resources such as cue cards and quick quizzes. They can complete the practice questions and peer mark with the mark scheme before correcting their work in order to develop exam technique. The second lesson can be completing an AFL test consisting of past paper questions. This can be marked to assess progress and identify opportunities to improve exam performance and possible intervention opportunities. Revisit and consolidate learning from Chapters 9 and 10 Identify areas of weakness which require further study Compare progress to MTG
In the third lesson the test can be reviewed and Students can correct their work and redraft answers. They should set their own targets for improvement; these can reference content or exam technique. One hour lessons Learning Outcomes Specification Content Skills Covered Student Book Section Required Practicals CHAPTER 5 – Cells (14 hours) 1 Cells and Living Organisms Students could recall prior knowledge and list examples of cells, tissues, organs, etc. Taboo could be used as an introductory game using key words or Pictionary. Students should recognise that all life on earth is dependent on cells. They should describe the adaptation of specialised cells and how they are organised in multicellular organisms. Recall how specialised cells are organised into tissues, organs and organ systems Describe how specialised cells are adapted for their functions 3.2.1.1 Structure of Eukaryotic Cells In complex multicellular organisms, eukaryotic cells become specialised for specific functions. Specialised cells are organised into tissues, tissues into organs and organs into systems. 5.1 2 and Living Organisms Students should revisit the use of optical microscopes to prepare them for the required practical. Correctly and safely use an Optical microscope Recall, use and rearrange the magnification formula 3.2.1.1 Structure of Eukaryotic Cells Use of the formula: magnification = size of image /size of real object MS0.1 MS0.2 MS1.2 MS1.8 MS2.2 MS2.3 MS2.5 MS4.1 5.4 3 Structure of Eukaryotic cells – Animal cells Students should be able to the required features in Recall labels for organelles found Eukaryotic cells (Animal) 3.2.1.1 Structure of Eukaryotic Cells The structure of eukaryotic cells, restricted to the structure and 5.2
• Golgi apparatus and Golgi vesicles • lysosomes (a type of vesicle that releases lysozymes) • ribosomes • rough endoplasmic reticulum and smooth endoplasmic reticulum • cell wall (in plants, algae and fungi) • cell vacuole (in plants). 5 Ultrastructure of Organelles Students need to be able to describe the ultrastructure of the main organelles and their functions. Students may draw the diagrams or produce a ‘junk model’ with labels to help cement learning. Clay models of these organelles can be made. Recall the ultrastructure of the nucleus, mitochondria and chloroplasts Give their functions Describe how they are adapted to their functions 3.2.1.1 Structure of Eukaryotic Cells The structure of eukaryotic restricted to the structure and function of: • nucleus (containing chromosomes, consisting of protein-bound, linear DNA, and one or more nucleoli) • mitochondria • chloroplasts (in plants and algae) 5.2 6 Comparing Eukaryotic Cells Students should be able to state the similarities and differences between the Eukaryotic cells types and how they are adapted to their Compare the organelles found in animal and plant cells 3.2.1.1 Structure of Eukaryotic Students should be able to their knowledge of these features 5.2
functions. A Venn diagram or table can be used to structure the comparison. This is an opportunity to develop exam technique by examining the same content using different command words. in explaining adaptations of eukaryotic cells. 7 Prokaryotic Cells and Viruses Students should recognise that not all cells are Eukaryotic. They should be able to recall the structure and function of the features of a prokaryotic cell. A clay model of a prokaryotic cell can be made. Students should be able to compare Eukaryotic and Prokaryotic cells, this can be done in a table. Recall the features and functions of a Prokaryotic cell Compare Eukaryotic and Prokaryotic cells Explain why Viruses are described as ‘acellular’ and ‘non-living’ 3.2.1.2 Structure of Prokaryotic cells and viruses Prokaryotic cells are much smaller than eukaryotic cells. They also differ from eukaryotic in having: • cytoplasm that lacks organelles • smaller ribosomes • no nucleus; instead they have a single circular DNA molecule that is free in the cytoplasm and is not associated with proteins • a cell wall that contains murein, a glycoprotein. In addition, many prokaryotic cells have: • one or more plasmids • a capsule surrounding the cell • one or more flagella. Details of these structural differences are not required. 5.3
Viruses are acellular and The structure of virus particles to include genetic material, capsid and attachment protein. 8 Methods of Studying Cells Students should be able to compare optical, electron and scanning electron microscopes. Students could complete a table with information about each device, its benefits and limitations. Students could use an optical microscope to view cells. Images of micrographs can be given and students have to calculate the actual size from the image and magnification. Compare optical and electron microscopes giving their advantages and limitations. 3.2.1.3 Methods of Studying The principles and limitations of optical microscopes, transmission electron microscopes and scanning electron microscopes. Measuring the size of an object viewed with an optical microscope. The difference between magnification and resolution. Use of the formula: magnification = size of image/size of real object Principles of cell fractionation and ultracentrifugation as used to separate cell components. Students should be able to appreciate that there was a considerable period of time during which the scientific community distinguished between artefacts and cell organelles. MS0.1 MS0.2 MS1.2 MS1.8 MS2.2 MS2.3 MS2.5 MS4.1 5.4 9 Methods of Studying Cells Students can complete a practical task using iodide to stain starch cells and using their observations in the magnification formula. Explain what is meant by magnification and resolution Use the magnification formula correctly 3.2.1.3 Methods of Studying Cells Measuring the size of an object viewed with an optical microscope. The difference between magnification and resolution. AT d, e and f Students could use iodine in potassium iodide solution to identify starch grains in plant cells. MS 1.8 5.4
Use of the formula: magnification = size of image/size of real object 10 Methods of Studying Students should be able to describe the steps in ultracentrifugation, the principle behind the process and how it allow us to study cells. If you have access to an ultracentrifuge Students could use it to extract the largest organelles. The analogy of a spinning ride with occupants of different sizes and masses can be used to illustrate the concept. Explain the stages in cell fractionation and ultracentrifugation and how it allows us to study organelles 3.2.1.3 Methods of Studying Principles of cell fractionation and ultracentrifugation as used to separate cell components. Students should be able to appreciate that there was a considerable period of time during which the scientific community distinguished between artefacts and cell organelles. 5.4 11 Making New Cells Students could complete Assignment 1: Controlling the Cell Cycle. Students should appreciate the role of Stem cells and how cell division leads to growth and repair. Students should recognise uncontrolled mitosis leads to the development of tumours and cancer. Recall the stages of cell cycle Explain how uncontrolled Mitosis can disease 3.2.2 All cells arrive from other cells Within multicellular organisms, not all cells retain the ability to divide. Eukaryotic cells that do retain the ability to divide show a cell cycle. • DNA replication occurs during the interphase of the cell cycle. Mitosis is a controlled process. Uncontrolled cell division can lead to the formation of tumours and of cancers. Many cancer treatments are directed at controlling the rate of cell division. MS0.1 MS0.5 MS1.3 MS2.5 PS1.2 PS2.4 PS3.1 5.5 12 Making New – Mitosis Students should recall the cell cycle and describe the stages of mitosis. Students could create a Describe the key features in each stage of Mitosis 3.2.2 All cells arrive from other cells • Mitosis is the part of the cell cycle in which a eukaryotic cell 5.5
explain the adaptation of specialised cells in relation to the rate of transport across their internal and external membranes. 4 The function of cell membranes Students should be able to list the factors affecting the rate of transport prior to learning about them in detail. It may help them to watch some animations. A poster of the cell membrane can be created to draw together all the concepts together on the cell membrane. Recall the factors affecting the rate of transport across cell membranes 3.2.3 Transport across cell membranes Students should be able to: explain how surface area, number of channel or carrier proteins and differences in gradients of concentration or water potential affect the rate of movement across cell membranes. 6.2 5 Movement across the cell membrane: diffusion Diffusion can be demonstrated using tea bags or spraying perfume. Students define diffusion and give examples of molecules that would move across the cell membrane this way. Factors affecting the rate of movement should be identified; this is an opportunity for students to practice calculating surface area. Students could draw and explain graphs showing diffusion with concentration of substance on the x-axis and rate of diffusion on the y-axis. Define and describe the passive method of diffusion across the cell membrane Explain the factors that can affect the rate of transport across the cell membrane Illustrate graphically movement across a cell membrane by diffusion 3.2.3 Transport across cell membranes Movement across membranes occurs by: simple diffusion (involving limitations imposed by the nature of the phospholipid bilayer) MS 1.2 Find arithmetic MS 1.3 Construct and interpret frequency tables and diagrams, bar charts and histograms MS 2.3 Substitute numerical values into algebraic equations appropriate units for physical quantities MS 3.1 Translate information between graphical, numerical and algebraic MS 4.1 Calculate the circumferences, surface and volumes of regular shapes 6.2
in solutions with differing water potentials. Venn diagrams can be completed to compare diffusion, facilitated diffusion and osmosis. 8 Practical: movement across the cell membrane by osmosis Students can produce a serial dilution of a solute to produce a calibration curve with which to identify the water potential of a plant tissue. Data collected can be plotted in an appropriate format and students could determine the water potential of plant tissues using the intercept of a graph of, e.g. water potential of solution against gain/loss of mass. Objectives can be chosen depending on the emphasis of the practical lesson: Select and use laboratory equipment accurately to collect experimental data Calculate and prepare a serial dilution Calculate a percentage change in mass Present data collected in a graph Interpret data collected to draw a conclusion Explain the steps in the scientific method 3.2.3 Transport across cell membranes Movement across membranes occurs by: osmosis (explained in terms of water potential) MS 0.3 Use ratios, fractions and percentages MS 3.2 Plot two variables from experimental or other data MS 3.4 Determine the intercept of a graph PS 2.2 Present data in appropriate ways PS 3.1 Plot and interpret graphs PS 3.2 Process and analyse data using appropriate mathematical skills as exemplified in the mathematical appendix for each science PS 4.1 Know and understand how to use a wide range of experimental and practical instruments, equipment and techniques appropriate to the knowledge and understanding included in the specification AT c Use laboratory glassware apparatus for a 6.3 Required practical 3: Production of a dilution series of a solute to produce a calibration curve with which to identify the water potential of plant tissue.
1 Cell surface antigens Prior knowledge of immunity can be assessed by asking students to write down a fact on sticky notes on immunity or by creating a mind map in pairs or small groups. Students can begin to create a glossary of key words which can be added to throughout the topic. Define key terms including cell surface antigens, immune response and phagocytes Identify how foreign antigens end up inside the body 3.2.4 Cell recognition and the immune system Each type of cell has specific molecules on its surface that identify it. These molecules include proteins and enable the immune system to identify: • pathogens • cells from other organisms of the same species • abnormal body cells • toxins Definition of antigen. The effect of antigen variability on disease and disease prevention. Phagocytosis of pathogens. The subsequent destruction of ingested pathogens by lysozymes. 7.1 2 Phagocytosis Students can create a cartoon to illustrate what happens in the process of phagocytosis. There are animations and real time videos of the process which can be watched. Describe the process of phagocytosis 3.2.4 Cell recognition and the immune system Phagocytosis of pathogens. The subsequent destruction of ingested pathogens by lysozymes. 7.2 3 The immune response Students match key terms and definitions using a card sort. This can be revisited at the end of the lesson or assessed through a game of taboo. A model of an antibody can be made using modelling clay. Define key terms including neutrophils, macrophages, antigen presenting cell, clonal selection, cytotoxic T cell, helper T cell, cytokines, memory cells, plasma cells , agglutination and immunoglobulin Identify different types of lymphocytes 3.2.4 Cell recognition and the immune system • Definition of antibody • Antibody structure • The formation of an complex, leading to the destruction of the antigen, limited to agglutination and phagocytosis of bacterial cells. 7.3
6 HIV and the immune system Using a card sort students could recall previous lessons and put together a flow chart of the cellular and humoral immune response. Students recall prior knowledge of the structure of a virus and relate it to the structure of HIV. Working in pairs or independently students could research and create a poster/presentation to meet the lesson objectives on HIV. Recall the cellular and humoral immune response Describe the structure of HIV Explain how HIV replicates and how it can be treated 3.2.4 Cell recognition and the immune system Structure of the human immunodeficiency virus (HIV) and its replication in helper T cells. How HIV causes the symptoms of AIDS. Why antibiotics are ineffective against viruses. 7.3 7.4 7 Monoclonal antibodies Students could try and define a monoclonal antibody in less than 20 words. A flow chart can be created or modelled to describe how monoclonal antibodies are used in ELISA tests. Assignment 4 can be used to frame discussion surrounding the ethics of using antibiotics. Define the term monoclonal antibody Explain how monoclonal antibodies can be used in diagnostic testing Discuss the ethics surrounding vaccination programmes, the use of monoclonal antibodies in diagnostic testing and use of antibiotics 3.2.4 Cell recognition and the immune system The use of monoclonal antibodies in: • targeting medication to specific cell by attaching a therapeutic drug to an antibody • medical diagnosis. Details of the production of monoclonal antibodies is not required. Ethical issues associated with the use of vaccines and monoclonal antibodies. The use of antibodies in the ELISA test. Students should be able to: • discuss ethical issues associated with the use of vaccines and monoclonal antibodies MS 3.1 Translate information between graphical, numerical and algebraic forms PS 1.2 scientific knowledge to practical contexts PS 2.1 Comment on experimental design and evaluate scientific methods PS 2.2Present data in appropriate ways PS 2.3 Evaluate results and draw conclusions with reference to measurement uncertainties and errors PS 3.1Plot and interpret graphs 7.5
One hour lessons Learning Outcomes Specification Content Skills Covered Student Book Section Required Practicals CHAPTER 8 - Exchange with the Environment (11 hours) 1 Surface area to volume ratio Students could be given the dimensions of simple cells with different shapes from which to calculate the surface area to volume ratios of these cells, this can be extended using assignment 1. Surface area to volume ratio can be investigated using agar blocks containing indicator to determine the effect of surface area to volume ratio and concentration gradient on the diffusion of an acid or alkali. Calculate surface area to volume ratio Describe the effects of surface area to volume ratio on the rate of exchange for an organism Identify features that help exchange in organisms 3.3.1 Surface area to volume ratio The relationship between the size of an organism or structure and its surface area to volume ratio. Changes to body shape and the development of systems in larger organisms as adaptations that facilitate exchange as this ratio reduces. Students should be able to appreciate the relationship between surface area to volume ratio and metabolic rate. MS 0.3 Use ratios, fractions and percentages MS 2.1 Understand and use the symbols: =, <, <<, >>, >, ∝,~ MS 2.2 Change the subject of an equation MS 2.3 Substitute numerical values into algebraic equations using appropriate units for physical quantities MS 2.4 Solve algebraic equations MS 4.1 Calculate the circumferences, surface areas and volumes of regular shapes PS 1.1 Solve problems set in practical contexts PS 3.2 Process and analyse data using appropriate mathematical skills as exemplified in the mathematical appendix for each science 8.1
them to change the subject of the equation. Alternatively students could use three-way taps, manometers and simple respirometers to measure volumes of air involved in gas exchange. about pressure changes in the thoracic cavity. 7 Gas exchange in humans Students may work in pairs to dissect a pair of mammalian lungs to illustrate the material covered in the previous lesson Complete a lung dissection 3.3.2 Gas exchange The gross structure of the human gas exchange system limited to the alveoli, bronchioles, bronchi, trachea and lungs. AT j Safely use instruments for dissection of an animal organ, or plant organ 8.3 8 Correlation and causation a light optical microscope students could observe the difference between a slide showing alveoli from a healthy lung and from one with emphysema. Assignment 4 can be used as a framework for discussing correlation and causation. A data set can be taken from the internet linking air quality and rates of asthma. Students work in small groups to present two contrasting arguments that can be taken from the data. Following this they should evaluate how data can be interpreted, identifying limitations of correlations and discuss how risk factors can be identified. Describe the difference between the terms correlation and causation Define the term risk factor Identify patterns in data presented graphically Evaluate data presented graphically Students should be able to: • interpret information relating to the effects of lung disease on gas exchange and/or ventilation • interpret data relating to the effects of pollution and smoking on the incidence of lung disease • analyse and interpret data associated with specific risk factors and the incidence of lung disease • evaluate the way in which experimental data led to statutory restrictions on the sources of risk factors • recognise correlations and causal relationships. MS 1.3 Construct and interpret frequency tables and diagrams, bar charts and histograms MS 1.7 Use a scatter diagram to identify a correlation between two variables PS 1.2 Apply scientific knowledge to practical contexts PS 2.1 Comment on experimental design and evaluate scientific methods PS 2.3 Evaluate results and draw conclusions with reference to measurement uncertainties and errors PS 3.1 Plot and interpret graphs 8.3
amino acids and fatty acids could be described in turn. Students can create a mind map to bring the ideas of digestion and absorption together. Practice questions at the end of the chapter can be used for students to apply their understanding. canal and into the epithelial cell Explain how products of digestion leave the epithelial cell. • co-transport mechanisms for the absorption of amino acids and of monosaccharides • the role of micelles in the absorption of lipids. One hour lessons Learning Outcomes Specification Content Skills Covered Student Book Section Required Practicals CHAPTER 9 - Mass Transport (10 hours) 1 Oxygen transport in mammals Clarification of key terminology is required including the terms affinity, association, dissociation, saturation and partial pressure. Students can recall the structure of haemoglobin from chapter 2. The oxygen dissociation curve should be drawn and annotated for human haemoglobin, to show the Bohr effect, for fetal haemoglobin and for at least one other animal such as the Llama or Tubifex worm. Application of knowledge should be tested through exam style questions. Define the mass transport and mass flow Describe the structure and function of haemoglobin Interpret the oxygen dissociation curve Explain the effect of carbon dioxide on the transport of oxygen Explain, using examples, why haemoglobin comes in many different forms 3.3.4.1 Mass transport in animals The haemoglobins are a group of chemically similar molecules found in many different organisms. Haemoglobin is a protein with a quaternary structure. The role of haemoglobin and red cells in the transport of oxygen. The loading, transport and unloading of oxygen in relation to the oxyhaemoglobin dissociation curve. The cooperative nature of oxygen binding to show that the change in shape of haemoglobin caused by binding of the first oxygen makes the binding of further oxygen easier. The effects of carbon dioxide concentration on the dissociation of oxyhaemoglobin (the Bohr effect). 9.1 9.2
change the subject of the equation cardiac output = stroke volume x heart rate. Assignment 1 can be used as a framework to practice calculating cardiac output and stroke volume. PS 3.2 Process and analyse data using appropriate mathematical skills as exemplified in the mathematical appendix for each science 4 Heart dissection and investigating heart rate Templates can be given for students to either independently or in pairs complete a heart dissection and following this plan an investigation into the effect of a named variable (for example exercise, caffeine) on human pulse rate or heart rate of Daphnia. This can be used as a planning activity only or it can be carried out as a full investigation using an additional lesson (9.5) Safely use instruments for dissection of an animal organ Identify structural features of the heart Design an investigation into the effect of exercise on human pulse rate or the effect of caffeine on the heart rate of an invertebrate, such as Daphnia 3.3.4.1 Mass transport in animals The gross structure of the human heart PS 1.1 Solve problems set in practical contexts PS 1.2 Apply scientific knowledge to practical contexts PS 2.4 Identify variables including those that must be controlled PS 4.1 Know and understand how to use a wide range of experimental and practical instruments, equipment and techniques appropriate to the knowledge and understanding included in the specification AT j Safely use instruments for dissection of an animal organ, or plant organ 9.3 9.4 Required practical 5: Dissection of animal or plant gas exchange system or mass transport system or of organ within such a system. 5 Investigating heart rate Use of Daphnia should promote a good ethical attitude towards them. Templates can be used to structure the planning process. Objectives can be chosen depending on the emphasis of the practical lesson: Design an investigation into the effect of a named variable 3.3.4.1 Mass transport in animals MS 1.3 Construct and interpret frequency tables and diagrams, bar charts and histograms 9.3
an artery and a vein can be observed using a light optical microscope. Students can make scientific drawings of their observations. Students could interpret a graph showing how pressure, cross sectional area and speed of blood flow changes through the various vessels. Describe and explain how blood pressure changes through the various vessels The structure of arteries, arterioles and in relation to their function. The structure of capillaries and the importance of capillary beds as exchange surfaces AT e Produce scientific drawing from observation with annotations 7 Formation of tissue fluid and cardiovascular disease Give students key phrases and terms to explain the formation of tissue fluid. Composition of tissue fluid and plasma could be compared. Students understanding of the formation of tissue fluid can be extended using the example of kwashiorkor and the accumulation of fluid with protein deficiency. Students could be given a data set to evaluate the incidence of cardiovascular disease and associated risk factors. Alternatively students can research using the internet what are the named risk factors for cardiovascular disease, to evaluate how much evidence there is for a causal relationship and to present their findings. Describe the difference between tissue and plasma Explain how tissue is formed at the capillary bed Evaluate the evidence associating risk factors with cardiovascular disease 3.3.4.1 Mass transport in animals The structure of capillaries and the importance of capillary beds as exchange surfaces. The formation of tissue fluid and its return to the circulatory system. Students should be able to: • analyse and interpret data associated with specific risk factors and the incidence of cardiovascular disease • evaluate conflicting evidence associated with risk factors affecting cardiovascular disease • recognise correlations and causal relationships 9.4 8 Transpiration Students could recall water potential from chapter 6 and properties of water from chapter 1. Transpiration could be modelled in the classroom using students as Define the term transpiration Explain the factors that affect the rate of transpiration Describe the structure of the vessel 3.3.4.2 Mass transport in plants as the tissue that transports water in the stem and leaves of plants. The cohesion-tension theory of water transport in the xylem 9.5
2 Genes, chromosomes and the genetic code Give students a list of key words and phrases to include in a written description of the genetic code. Students could determine the sequence of amino acids from a sequence of nucleotide bases. Assignment 1 can be used to draw together student’s current understanding of DNA. Compare how DNA is organised in eukaryotic and prokaryotic cells 3.4.1 DNA, genes and chromosomes In prokaryotic cells, DNA molecules are short, circular and not associated with proteins. In the nucleus of eukaryotic DNA molecules are very long, linear and associated with proteins, called histones. Together a DNA molecule and its associated proteins form a chromosome. The mitochondria and chloroplasts of eukaryotic cells also contain DNA which, like the DNA of prokaryotes, is short, circular and not associated with protein. A gene is a base sequence of DNA that codes for: • the amino acid sequence of a polypeptide • a functional RNA (including ribosomal RNA and tRNAs) A gene occupies a fixed position, called a locus, on a particular DNA molecule. A sequence of DNA bases, called a triplet, codes for a specific amino acid. The genetic code is universal, non-overlapping and degenerate. PS 1.2 scientific knowledge to practical contexts 10.1 10.2
In eukaryotes, much of the nuclear DNA does not code for polypeptides. There are, for example, non-coding multiple repeats of base sequences between genes. Even within a gene only some sequences, called exons, code for amino acid sequences. Within the gene, these exons are separated by one or more non-coding sequences, called introns. 3 Transcription The genetic code can be reviewed briefly from the previous lesson. Key terminology including proteome, transcription and mRNA should be defined. There are numerous video clips that can be found on YouTube to illustrate transcription. The process of transcription can be written as a flow chart. Students can determine the sequence of bases on mRNA from a given DNA molecule. Modelling clay can be used to construct a model showing the process of splicing. Differences between DNA and mRNA can be listed. Define the terms proteome, codon and transcription Describe the role of mRNA Explain how mRNA is produced in transcription 3.4.2 DNA and protein synthesis The concept of the genome as the complete set of in a cell and of the proteome as the full range of proteins that a cell is able to produce. Transcription as the production of mRNA from DNA. The role of RNA polymerase in joining mRNA nucleotides. Students should be able to: • relate the base sequence of nucleic acids to the amino acid sequence of polypeptides, when provided with suitable data about the genetic code Students will not be required to recall in written papers specific codons and the acids for which they code. 10.3
4 Transcription Students can determine the sequence of bases on mRNA from a given DNA molecule. Modelling clay can be used to construct a model showing the process of splicing. Differences between DNA and mRNA can be listed. Describe the difference between pre mRNA and mature mRNA 3.4.2 DNA and protein synthesis • In prokaryotes, transcription results directly in the production of mRNA from DNA. • In eukaryotes, transcription results in the production of this is then spliced to form mRNA. 10.3 5 Transcription Students may draw and annotate diagrams of mRNA and tRNA. They could also make models Recall the structure of mRNA and tRNA 3.4.2 DNA and protein synthesis The structure of molecules of messenger RNA (mRNA) and of transfer RNA (tRNA). 10.3 6 Translation Students can draw a cartoon to illustrate the process of translation. Construct a table to compare transcription and translation, as an extension DNA replication from chapter 4 can also be compared. Similarities and differences between tRNA and mRNA can be listed. Practice questions at the end of the chapter can be completed for students to apply their understanding. Assignment 2 can be used as an extension looking at the role of polyribosomes. Describe the structure and role of tRNA and a ribosome Describe how a polypeptide is produced during translation Compare the processes of transcription and translation 3.4.2 DNA and protein synthesis Translation as the production of polypeptides from the sequence of codons carried by mRNA. The roles of ribosomes, tRNA and ATP. Students should be able to: • relate the base sequence of nucleic acids to the amino acid sequence of polypeptides, when provided with suitable data about the genetic code • interpret data from experimental work investigating the role of nucleic acids Students will not be required to recall in written papers specific codons and the amino acids for which they code. PS 1.1 Solve problems set in practical contexts PS 1.2 Apply scientific knowledge to practical contexts 10.3
3 Meiosis Students recall as many points about mitosis as they can from chapter 5. Students could begin to learn the new key word definitions using a game such as ‘who am I?’ Diagrams showing the 2 divisions in meiosis can be drawn and annotated. Students could examine meiosis in prepared slides of suitable plant or animal tissue and identify any differences with mitosis they might see. Using this and new information on meiosis a table can be constructed to compare the main differences between the 2 processes. Students should be able to synthesis ideas about when meiosis may occur in non-mammal life cycles. Define key including homologous chromosomes, haploid, diploid and bivalent Describe the role of meiosis Compare meiosis with mitosis Identify meiosis may happen in a variety of life cycles. 3.4.3 Genetic diversity can arise as a result of mutation or during meiosis Meiosis produces daughter cells that are genetically different from each other. The process of meiosis only in sufficient detail to show how: • two nuclear divisions result usually in the formation of four haploid daughter cells from a single diploid parent cell Students should be able to: • complete diagrams showing the chromosome content of cells after the first and second meiotic division, when given the chromosome content of the parent cell Students should be able to: • explain the different outcome of mitosis and meiosis • recognise where meiosis occurs when given information about an unfamiliar life cycle AT d Use of microscope at high power and low power, including use of a graticule 11.2 4 Sources of genetic variation Using different colour pipe cleaners independent assortment and crossing over can be modelled Name 3 sources of genetic variation Describe the 3 sources of genetic variation 3.4.3 Genetic diversity can arise as a result of mutation or during meiosis MS 0.5 Use calculators to find and use power, exponential and logarithmic functions 11.2
increases genetic variation within a species 6 Natural Selection Students can be provided with scenarios which describe the variation within a population and a selection pressure. In pairs students could then predict what they think will happen in future generations. A flow chart could be created to explain the steps involved in natural selection. There are numerous YouTube clips to illustrate natural selection. Direction and stabilising selection can be illustrated in the form of a graph and described using examples to visualise the selection. Define genetic diversity Explain the advantages of genetic diversity Describe the steps in the theory of natural selection Explain the difference between directional and stabilising selection 3.4.4 Genetic diversity and adaptation Genetic diversity as the number of different alleles of genes in a population. Genetic diversity is a factor enabling natural selection to The principles of natural selection in the evolution of populations. • Random mutation can result in new alleles of a gene. • Many mutations are harmful but, in certain environments, the new allele of a gene might benefit its possessor, leading to increased reproductive success. • The advantageous allele is inherited by members of the next generation. • As a result, over many generations, the new allele increases in frequency in the population. Directional selection, exemplified by antibiotic resistance in bacteria, and stabilising selection, exemplified by birth weights. Natural selection results in species that are better adapted to their environment. These adaptations 11.3
calculations and consolidation. The presence or absence of microbial growth can be linked back to the development of antibiotic resistance through natural selection. Use scientific understanding to form a hypothesis Calculate an estimate of bacterial population size variety of experimental techniques to include serial dilutions AT i Use microbiological aseptic techniques, including the use of agar plates and broth One hour lessons Learning Outcomes Specification Content Skills Covered Student Book Section Required Practicals CHAPTER 12 – Taxonomy and biodiversity (7 hours) 1 The Species Concept Students should recall the definition of ‘Species’. Give students a variety of pictures of different organisms and they have to try and classify, put the organisms into groups, they must be able to justify their reason for doing so. This should elicit why classifying species is sometimes difficult. Students should be able to define the Phylogenetic classification as a hierarchy of groups within groups without overlap. They should recall the taxa and the binomial system used to identify species. Students should be able to explain how Recall what is meant by a Species and the order of taxa of Phylogenetic classification Explain why it may be difficult to identify new species Utilise the binomial system of naming species Explain techniques which provide evidence to clarify evolutionary relationships 3.4.5 Species and Taxonomy Two organisms belong to the same species if they are able to produce fertile offspring. Courtship behaviour as a necessary precursor to successful mating. The role of courtship in species recognition. A phylogenetic classification system attempts to arrange species into groups based on their evolutionary origins and relationships. It uses a hierarchy in which smaller groups are placed within larger groups, with no overlap between groups. Each group is called a taxon (plural taxa). One hierarchy comprises the taxa: domain, kingdom, phylum, 12.1
courtship behaviours, immunology and genome sequencing provide evidence for evolutionary relationships. class, order, family, genus and species. Each species is universally identified by a binomial consisting of the name of its and species, e.g., Homo sapiens. Recall of different taxonomic systems, such as the three domain or five kingdom systems, will not be required. Students should be able to appreciate that advances in immunology and genome sequencing help to clarify evolutionary relationships between organisms. 2 Biodiversity Student could complete Assignment 1: Investigating the effect of hedges on crop yield. Students should recall what is meant by Biodiversity and why it is an important measure of a habitats fitness. Students should be able to use the index of diversity to compare habitats. Students should be able to discuss the impacts of farming on biodiversity and how to balance productivity and conservation. Explain what is meant by Biodiversity Use the index of diversity to compare habitats Discuss how farming impacts biodiversity and how to minimise this 3.4.6 Biodiversity within a community Biodiversity can relate to a range of habitats, from a small local habitat to the Earth. Species richness is a measure of the number of different species in a community. An index of diversity describes the relationship between the number of species in a community and the number of individuals in each species. Calculation of an index of diversity (d) from the formula MS3.1 PS1.2 PS3.2 MS 2.3 Students could be given data from which to calculate an index of diversity and interpret the significance of the calculated value of the index. 12.2
from measurable or observable characteristics has been replaced by direct investigation of DNA sequences. Knowledge of gene technologies will not be tested. 4 Investigating diversity Students should also collect their own data and calculate means and standard deviation demonstrating an understanding of what this shows. Use this as an opportunity to develop an understanding of experimental design and sampling techniques. Data such as leaf size from different trees or number of spines on Holly leaves are ideal but data must be gathered from within the same Species. Data can be collected on each other, e.g. height, hand span, foot length etc. Collect your own data and calculate standard deviation 3.4.7 Investigating Diversity Quantitative investigations of variation within a species involve: • collecting data from random samples • calculating a mean of the collected data and the standard deviation of that mean • interpreting mean values and their standard deviations. Students will not be required to calculate standard deviations in written papers. AT k Students could: • design appropriate methods to ensure random sampling • carry out random sampling within a single population • use random samples to investigate the effect of position on the growth of leaves. MS 1.2 Students could use standard scientific calculators to calculate the mean values of data they have collected or have been given. MS 1.10 Students could calculate, and interpret the values of the standard deviations of mean values. 5-7 Consolidating/revision In the first lesson Students can spend a lesson consolidating Revisit and consolidate learning from Chapters 9 and 10