Variety of life, adaptation and competition
(a) Understand that living organisms show a range of sizes, features and complexity. Appreciate the broad descriptive grouping into plants - non- flowering and flowering; animals - invertebrates and vertebrates; microorganisms – fungi, bacteria, algae. (Detailed knowledge of group features is not required.)
(b) Know that organisms which have similar features and characteristics can be classified together in a logical way. Morphological features or DNA analysis can be used and as more information becomes available changes are made to the classification. Recently the 3 Domain classifications have been preferred to the 5 Kingdom classifications. Understand the need for a scientific system for identification and the need for scientific as opposed to 'common' names. Know that international committees decide on scientific names.
(c) Investigate and understand that organisms have morphological and behavioural adaptations which enable them to survive in their environment. Possible investigations: Identification of freshwater invertebrates in enclosed water (e.g. pond or water butt) and their respiratory adaptations.
(d) Know that the types of organisms in an area are affected by other types of organisms by investigating relationships using local or second hand data/ ICT modelling.
(e) Know that individual organisms have a need for resources from their environment e.g. food, water, light and minerals and understand that the size of a population may be affected by competition for these resources along with predation, disease and pollution.
Monitoring the environment, energy flow and nutrient transfer
(a) Understand the issues surrounding the need to balance the human requirements for food and economic development with the needs of wildlife. Discuss how the collection of detailed, reliable scientific information and monitoring by biologists could help to inform, manage and reduce the impact of development on the environment e.g. the role of the Environment Agency.
(b) Discuss the advantages and drawbacks of intensive farming methods, such as using fertilisers, pesticides, disease control and battery methods to increase yields. Investigate the issues surrounding the question of the source of TB infection in cattle, including the role of the scientific community in planning valid experiments in order to inform policy decisions and how different interpretations can be applied to reach various possible outcomes.
(c) Investigate using suitable data, how indicator species and changes in pH and oxygen levels may be used as signs of pollution in a stream and investigate how lichens can be used as indicators of air pollution. Understand that mathematical modelling can be used to analyse and predict effects.
Possible investigations: Use of oxygen/pH sensors to investigate pollution levels in waterways.
(d) Explore information about the heavy metals which may be present in industrial waste and the types of pesticides used on crops. Some of these chemicals enter the food chain, accumulate in animal bodies and may reach a toxic level and so have harmful effects. Discuss and understand that the effects of pesticides, such as DDT, became apparent in the early 1960s and the initial observation, accumulation and interpretation of scientific evidence emphasised the need to monitor the effects and control the use of these chemicals.
(e) Understand that untreated sewage and fertilisers may cause rapid growth of photosynthesises, plants and algae, in water. When the plants and algae die, the microbes, which break them down, increase in number and further use up the dissolved oxygen in the water. Animals, including fish, which live in the water, may suffocate.
Possible investigations: Exploring the effect of increasing concentrations of nitrate on the growth of duckweed (Lemna).
(f) Understand that radiation from the Sun is the source of energy for most ecosystems/communities of living organisms and that green plants, and other photosynthetic organisms such as algae, capture a small percentage of the solar energy which reaches them. Investigate data about food chains and food webs and understand that they show the transfer of energy between organisms and involve producers; first, second and third stage consumers; herbivores and carnivores.
(g) Understand that at each stage in the food chain energy is used in repair and in the maintenance and growth of cells whilst energy is lost in waste materials and as heat during respiration.
(h) Use data to construct and interpret pyramids of numbers and biomass.
(i) Understand that carbon is constantly cycled in nature by the carbon cycle via photosynthesis which incorporates it and respiration which releases it.
(j) Know that micro-organisms, bacteria and fungi, feed on waste materials from organisms and that when plants and animals die their bodies are broken down by microorganisms bringing about decay. These microorganisms respire and release carbon dioxide into the atmosphere. Understand what happens when decay is prevented. Burning fossil fuels releases carbon dioxide.
Possible investigations: Investigate the decay of leaves in different environmental conditions e.g. soil pH, temperature and in bags of different mesh size. Experiments to investigate the microbial decay of fruit or vegetables.
(k) Understand that nutrients are released in decay, e.g. nitrates and phosphates, and that these nutrients are then taken up by other organisms resulting in nutrient cycles. In a stable community the processes which remove materials are balanced by processes which return materials.
(l) Understand that nitrogen is also recycled through the activity of soil bacteria and fungi acting as decomposers, converting proteins and urea into ammonia. This is converted to nitrates which are taken up by plant roots and used to make new protein. Computer modelling may be used to investigate and predict the effects of factors influencing the process. (Denitrification and nitrogen fixation are not required.)
(m) Investigate the action of urease on urea.
(a) Understand that genes are sections of DNA molecules that determine inherited characteristics and are in pairs. Genes have different forms, called alleles.
(b) Know that chromosomes are linear arrangements of genes and that chromosomes that are found in pairs in body cells are strands of DNA. DNA contains coded information for the production of different types of proteins. These proteins determine how cells function.
Possible investigations: practical extraction of DNA from cells.
(c) Understand that an organism's DNA can be analysed by 'genetic profiling' and how this can be used to show the similarity between two DNA samples. The process involves cutting the DNA into short pieces which are then separated into bands. The pattern of the bands produced can be compared to show the similarity between two DNA samples, for instance in criminal cases, paternity cases and in comparisons between species for classification purposes. Advances in technology now make such analysis widely available.
(d) Discuss the benefits of DNA profiling, for example to identify the presence of certain genes which may be associated with a particular disease. As this likelihood may be based on statistical probability, understand that it raises issues such as risk-benefit considerations and disclosure of information along with wider ethical issues of ownership and human rights which are subject to value judgement by society.
(e) Understand that when gametes are formed the chromosome number is halved and the genetic composition of the daughter cells is not identical (the term, meiosis, and knowledge of stages are not required). Fertilisation restores normal chromosome number.
(f) Know that in human body cells, one of the pairs of chromosomes, XX or XY, carries the genes which determine sex. These separate and combine randomly at fertilisation.
(g) Be able to understand and complete Punnett squares and explain the outcomes of monohybrid crosses including ratios. The following terms should be understood: genotype, phenotype, dominant, recessive, F1, F2, selfing, heterozygous, heterozygote, homozygous and homozygote and an understanding of simple Mendelian ratios. (Incomplete dominance is not required.) Understand that most characteristics are controlled by more than one gene.
(h) Consider the scientific process of observation, experimentation and deduction that led Gregor Mendel to propose the mechanism of inheritance. Discuss why the significance of the work was not recognised and validated by scientists for many years.
(i) Know that genes can be transferred artificially from one species to another. Understand that the introduction of genes from herbicide-resistant plants into soya bean plants, so increasing their resistance to herbicides, may increase the crop yield due to reduced competition. Understand the potential disadvantages and issues involved. (Names of enzymes are not required.)
(j) Investigate and evaluate the potential benefits and problems posed by advances in GM crop technology. Understand the need to collect reliable data, e.g. the use of farm scale field trials, in order that possible effects on the environment and on health should be understood. The data may be used to help formulate policy decisions regarding the planting of these crops and to inform consumers. Understand the need for unbiased information and interpretation as it affects the public perception of foods containing GM products and informs risk management considerations of possible consequences.
(a) Examine the variation in height/length in individuals of the same species by collecting and analysing data and know that variation may be due to environmental or genetic causes. Understand that variation may be continuous or discontinuous.
(b) Understand that sexual reproduction leads to offspring that are genetically different from the parents unlike asexual reproduction where genetically identical offspring called clones are produced from a single parent. Sexual reproduction therefore gives rise to increased variation.
(c) Understand that new genes result from changes, mutations, in existing genes and that mutations occur at random. Most mutations have no effect but some may be beneficial or harmful. Mutation rates can be increased by ionising radiation. (Reference to specific ionising radiation is not required.)
(d) Understand that some mutations cause conditions which may be passed on in families, as is shown by the mechanism of inheritance of cystic fibrosis, and be able to interpret family trees. Discuss the issues surrounding the development and use of gene therapy which has been tried as a means to alleviate the symptoms in cystic fibrosis sufferers but has greater potential as advances are made in knowledge and technology.
(a) Know that heritable variation is the basis of evolution.
(b) Consider how individuals with characteristics adapted to their environment are more likely to survive and breed successfully. Discuss the use and limitations of a model to illustrate the effect of camouflage colouring in predator and prey relationships.
(c) Know that the genes which have enabled these better adapted individuals to survive are then passed on to the next generation. This is natural selection as proposed by Charles Darwin and accepted by scientists. Work continues to fully understand the process as further evidence from genetics and molecular biology is collected. The process of natural selection is sometimes too slow for organisms to adapt to new environmental conditions and so organisms may become extinct.
Possible investigations: a model for natural selection - spaghetti worms.
(d) Understand that evolution is ongoing as shown by the development of resistance to antimicrobial chemicals by bacteria or Warfarin resistance in rats.
Response and regulation
(a) Know that sense organs are groups of receptor cells, which respond to specific stimuli: light, sound, touch, temperature, chemicals, and then relay this information as electrical impulses along neurones to the central nervous system. (Details of structure of sense organs is not required.)
(b) Investigate sensitivity and reaction times.
Possible investigations: falling metre rule experiment; assessing skin sensitivity - temperature receptors.
(c) Explore experimentally the positive response of plant shoots to light, phototropism, and plant roots to gravity, gravitropism. Phototropism is due to a plant hormone. (Details of hormones or mechanism are not required). Possible investigations: time lapse photography of markers on plants could be used to compare growth rates/responses by different species and/or under different conditions.
(d) Understand the reasons why animals need to regulate the conditions inside their bodies to keep them relatively constant and protected from harmful effects.
(e) Understand that hormones are chemical messengers, carried by the blood, which control many body functions. Investigate data showing the relationship between glucose and insulin levels in the blood. Understand that glucose levels need to be kept within a constant range so when the blood glucose level rises, the pancreas releases the hormone insulin, a protein, into the blood. This causes the liver to reduce the glucose level by converting glucose to insoluble glycogen and then storing it.
(Details of endocrine glands, other hormones, glucagon are not required.)
(f) Know that diabetes (type 1) is a condition in which a person's blood glucose may rise to a fatally high level because the body does not produce enough insulin. Understand that it can be diagnosed by the presence of glucose in the urine and the methods of treating the condition. Carry out testing of artificial urine samples for glucose using a suitable method, such as Benedict’s.
(g) Recognise and label a simplified given diagram of a vertical section through the skin to show: hair, erector muscle, sweat gland, sweat duct, sweat pore, and blood vessels. Understand the role of these structures in temperature regulation: change in diameter of blood vessels, sweating, erection of hairs; shivering as a means of generating heat.
Possible investigations: Investigate and interpret information about sweating and temperature; observe prepared sections of skin under a microscope.
(h) Understand the principles of negative feedback mechanisms to maintain optimum conditions inside the body as illustrated by the control of glucose levels by insulin and glucagon and by the control of body temperature.
(a) understand that different foods have different energy content and understand that energy from food, when it is in excess, is stored as fat by the body. Investigate experimentally the comparative energy content of different foods by burning. (Peanuts should not be burned due to the risk of allergy.)
(b) Explore and discuss available data, e.g. from ICT searches and food labelling, about the sugar, fat and additives in foods and the implications, particularly for health.
(c) Understand that some conditions are affected by lifestyle choices and investigate information/data about the effects that alcohol and drug abuse have on the chemical processes in people's bodies. Examine and consider data about the incidence of diabetes (type 2 ) and the possible relationship with lifestyle.
(d) Understand that health is affected by a variety of factors and that science and technology may provide the answer to some health problems. Understand that some treatments may involve risk-benefit assessments.
(e) Understand that some conditions can be prevented in a variety of ways and that some can be treated by drugs or by other therapies. Discuss the associated issues some of which may be viewed from a scientific and moral perspective.
(f) Understand that new drug treatments may have side effects and extensive, large scale; rigorous testing is required including risk management. Discuss the associated risks, benefits and ethical issues including the use of animals for testing drugs and whether this is superseded by new technologies.
Elements & the periodic table
(a) Understand that elements are the basic building blocks of all substances and cannot be broken down into simpler substances by chemical means.
(b) Know that elements are made up of only one type of atom and that each atom contains a positively charged nucleus and orbiting negatively charged electrons.
(c) be aware that Mendeleev, in developing the modern form of the Periodic Table, observed recurring patterns in the properties of elements when arranged in order of relative atomic mass, but used creative thought to realise that he needed to leave gaps for elements that had not been discovered at that time; this enabled him to predict the properties of the undiscovered elements.
(d) Be able to describe an element's position in the Periodic Table in terms of its group and its period.
(e) Know that metals are good conductors of heat and electricity, malleable and ductile, and are generally hard, dense and shiny with high melting points and boiling points, while non-metals are generally poor conductors with low melting points and boiling points.
(f) appreciate that metals are found on the left hand side and in the centre of the Periodic Table, non-metals on the right-hand side and that elements with intermediate properties are found between the metals and non-metals e.g. silicon in Group 4.
(g) Examine data about the physical and chemical properties of elements to establish trends within groups and to make predictions based on these trends.
(a) Know that in a chemical reaction, atoms are rearranged but none are created or destroyed.
(b) Understand that new substances called compounds are formed when atoms of two or more elements combine and that each compound has its own chemical formula.
(c) be able to interpret given chemical formulae i.e. name the elements, state the number of atoms of each element and the total number of atoms present, including formulae containing hydroxide, nitrate, carbonate and sulphate ions.
(d) Be able to draw and interpret space-filler type diagrams for simple molecules using a key (showing an appreciation of which atoms are joined to which).
(e) Understand that electrons are transferred from metal atoms to non-metal atoms, forming positively charged metal ions and negatively charged non- metal ions, when ionic compounds are formed.
(f) be able to write chemical formulae for ionic compounds given the formulae of the ions that they contain, including formulae containing hydroxide, nitrate, carbonate and sulphate ions.
(a) Know that ores found in the Earth's crust contain metals combined with other elements and that these metals can be extracted using chemical reactions.
(b) Understand that some unreactive metals (e.g. gold) can be found uncombined and that the difficulty involved in extracting metals increases as their reactivity increases.
(c) investigate the relative reactivity’s of metals by displacement (e.g. iron nail in copper(II) chloride solution) and competition reactions (e.g. thermite reaction) and write and interpret word equations and balance symbol equations to describe the reactions, including those which feature nitrates and sulphates.
(d) Explain reduction and oxidation in terms of removal or gain of oxygen and recognise their occurrence in reactions e.g. during thermite reaction and in the blast furnace.
(e) Explain why iron ore, coke and limestone are the raw materials placed in the blast furnace in order to extract iron.
(f) Write and interpret the word equation for the reduction of iron (III) oxide by carbon monoxide and balance the symbol equation.
(g) Understand that the extraction of aluminium requires greater energy input than the extraction of iron and that the method used to extract the most reactive metals (including aluminium) is electrolysis.
(h) Explain the process of electrolysis of molten ionic compounds e.g. lead (II) bromide, in terms of ion movement and electron gain/loss, using the terms electrode, anode, cathode and electrolyte.
(i) Balance given electrode equations in terms of charge and atoms.
(j) Apply their understanding of electrolysis to the industrial extraction of aluminium and balance the following electrode equations in terms of charge and atoms.
Al3++3e- → Al
2O2--4e- → O2
(k) Discuss issues of sustainability relating to the extraction of metals including iron and aluminium e.g. siting of plants, fuel & energy costs, and greenhouse emissions and recycling, and evaluate the social and economic impact of their extraction and use.
(l) explain the uses of aluminium, copper and titanium in terms of the following relevant properties:
aluminium – strong, low density, good conductor of heat and electricity, resistant to corrosion
copper – very good conductor of heat and electricity, malleable and ductile, attractive colour and lustre
Titanium – hard, strong, low density, resistant to corrosion, high melting point.
(m) Understand that an alloy is a mixture made by mixing molten metals and that its properties can be modified by changing its composition.
(n) Know that nano-scale silver particles have antibacterial, antiviral and anti-fungal properties leading to new uses in hygiene and medicine.
(o) Relate the uses of nano-scale particles to their properties.
(p) Assess the potential risks of current and future developments in nanoscience in the context of potential benefits e.g. using nano-scale materials in battery electrodes for electric vehicles or in solar cells.
(a) Know that many non-metals, including nitrogen, oxygen, neon and argon, are found in the air.
(b) Understand that hydrogen and oxygen can be produced from water by electrolysis and that twice the volume of hydrogen as oxygen is produced.
(c) Carry out tests to identify hydrogen gas and oxygen gas.
(d) Know that hydrogen burns in air, releasing usable energy, and be able to write and interpret the word equation and balance the symbol equation for the reaction.
(e) Discuss and explain the advantages and disadvantages of hydrogen as a fuel in terms of its abundance, combustion product, renewability and storage issues, extraction costs and safety issues.
(f) Know that chlorine and iodine can be obtained from compounds in sea water but appreciate that this is no longer considered to be an economically viable source of iodine.
(g) explain the uses of chlorine, iodine, helium, neon and argon in terms of the following relevant properties:
chlorine – poisonous/toxic, kills bacteria
Iodine – poisonous/toxic, kills bacteria
Helium – very low density, very unreactive
neon – emits light when electric current passes through it
Argon – very unreactive.
(h) Know that sodium fluoride, taken in toothpaste or in the water supply, prevents tooth decay and appreciate that scientists gathered evidence to establish this fact by a range of survey techniques.
(i) Understand the arguments for and against fluoridation of the water supply, including the ethical issue of removing freedom of choice for the individual.
Reactions of acids
(a) Be able to classify substances as acidic, alkaline or neutral in terms of the pH scale, including acid/alkali strength.
(b) Investigate the reactions of acids with metals and explain their observations in terms of the metals' position in the reactivity series.
(c) Know that the neutralisation of dilute acids with bases (including alkalis) and carbonates is exothermic and that carbonates effervesce in acid and that these patterns can be used to make predictions and plan procedures to distinguish between given bases, carbonates and salts.
(d) Carry out test to identify carbon dioxide gas.
(e) Prepare crystals of soluble salts, such as copper (II) sulphate, from insoluble bases and carbonates.
(f) be able to write and interpret word equations and balance chemical equations to describe the reactions of metals, bases (including alkalis) and carbonates with the following acids: hydrochloric acid, nitric acid and sulphuric acid.
The production & uses of fuels & plastics
(a) Understand that crude oil is a complex mixture of hydrocarbons that was formed over millions of years from the remains of simple marine organisms.
(b) Appreciate that crude oil is a finite resource and that decisions made about its uses have global social, economic and environmental impact.
(c) Know that crude oil is separated into less complex mixtures, called fractions, which contain hydrocarbons with boiling points in the same range.
(d) Understand that while most fractions are used as fuels, others are further processed by cracking to make small, reactive molecules called monomers, which can be used to make plastics.
(e) Know that small reactive molecules called monomers are joined together to form polymers in a process known as polymerisation.
(f) Understand that many plastics, including polythene, PVC, PTFE and polystyrene, are made by polymerisation and recall the general properties of plastics.
(g) Explain the uses of given plastics in terms of their properties.
(h) Discuss and explain the environmental issues relating to the disposal of plastics, in terms of their non-biodegradability, increasing pressure on landfill for waste disposal, and how recycling addresses these issues as well as the need to carefully manage the use of natural resources such as oil.
The ever-changing earth
(a) be able to briefly describe the theory of plate tectonics and know that it developed from Alfred Wegener's earlier theory known as continental drift.
(b) Appreciate that the earlier theory was not accepted by other scientists because Wegener could not explain how or why the continents moved.
(c) Describe the evidence, discovered at a later date, which led to the theory of plate tectonics being accepted by other scientists.
(d) Know that the distribution of major earthquakes and volcanoes can be used to identify plate boundaries.
(e) Know that the original atmosphere was formed by gases, including carbon dioxide and water vapour, being expelled from volcanoes.
(f) Understand how the composition of the atmosphere has changed over geological time and recall its approximate present day composition.
(g) Understand the roles of respiration, combustion and photosynthesis in the maintenance of the levels of oxygen and carbon dioxide in the atmosphere.
(h) Appreciate that there is much media debate on the issue of global warming and be aware that the vast majority of scientists attribute the main cause of global warming to the increase in carbon dioxide in the atmosphere caused by the combustion of fossil fuels.
(i) Explain the environmental effects and consequences of the emission of carbon dioxide and sulphur dioxide into the atmosphere through the combustion of fossil fuels.
(j) Evaluate proposed solutions to the problems of global warming and acid rain e.g. 'carbon capture' and 'sulphur scrubbing'.
Generation of electricity
(a) be aware of the usefulness of electricity as a means of energy transfer.
(b) be aware of the significance of commissioning costs, running costs (including fuel) and decommissioning costs for power stations and respond to data concerning these costs for fossil fuel, nuclear and non-thermal power stations.
(c) compare the advantages and environmental impact of different forms of electrical power generation including micro-generation, e.g. using domestic wind turbines and roof-top photovoltaic cells.
(d) use data to estimate the power output of power stations and micro generators e.g. from energy content of fuel and conversion efficiency.
(e) experimentally determine the density of materials, including air and water, and use knowledge of density to inform discussion of the energy available from moving water and air.
(f) select and use the equation:
density= mass / volume
Transmission of electricity
(a) understand the need for an electricity distribution system, in terms of maintaining a reliable energy supply which is capable of responding to a fluctuating demand.
(b) describe the National Grid in terms of power stations, substations and power lines.
(c) explain in terms of energy efficiency and safety, why electricity is transmitted at high voltages but used at low voltages in the home and hence the need for transformers in the national grid.
(d) investigate the operation of step-up and step-down transformers, e.g. using demountable transformers, C-cores or computer models, in terms of the input and output voltage, current and power. [N.B The operation of a transformer in terms of electromagnetic induction and turns ratio will not be examined in this unit.]
(e) select and use the equation:
power = voltage current; P = VI
in relation to the supply of power from power stations, its transmission and receipt by the end user.
Energy supply and the home
(a) distinguish between power and energy and select and use the equation: energy transfer = power time ; E = Pt.
(b) select and use the equations:
Units used (kWh) = power (kW) time (h)
cost = units used cost per unit
together with information on the power ratings of domestic electrical
appliances and investigate the cost of using them.
(c) use data to make comparisons of different sources of domestic energy, including cost comparisons of traditional sources, e.g. electricity, gas, oil and coal, and the cost-effectiveness and environmental implications of introducing alternative energy sources, e.g. domestic solar and wind energy equipment.
(a) use energy transfer (Sankey) diagrams and understand qualitatively the idea of energy efficiency in terms of input energy, useful output energy and wasted energy.
(b) investigate the efficiency of energy transfer in electrical contexts, e.g. using an electrical energy meter and a kettle.
(c) select and use the equation:
% efficiency = useful energy [or pow er]transfer 100
total energy [or power] input
in a range of contexts including electrical power generation and transmission.
(d) understand the relevance of the efficiency of fossil-fuel power stations and the national grid to the environmental debate on carbon footprint and anthropogenic global warming.
(e) explore experimentally how temperature differences lead to the thermal transfer of energy by conduction, convection and radiation – a particle explanation for conduction will not be examined, but candidates should be aware that density changes result in natural convection. See section 5 below for thermal radiation.
(f) understand how energy loss from houses can be restricted and use data to compare the economics of domestic insulation techniques, e.g. loft insulation and double glazing.
The characteristics of waves
(a) characterise waves in terms of their wavelength, frequency, speed and amplitude.
(b) select and apply the equations
wave speed = wavelength frequency; c = f , and
speed = distance / time
to the motion of waves, including electromagnetic waves.
(c) investigate the speed of waves, e.g. of water waves in a storage tray, and compare the speed of sound waves in air and wood.
(d) distinguish between the different regions of the electromagnetic spectrum [radio waves, microwaves, infra red, visible light, ultra violet, X rays and gamma rays] in terms of their wavelength and frequency and appreciate that they all travel at the same speed in a vacuum.
(e) appreciate that all regions of the electromagnetic spectrum transmit information and energy.
(f) identify thermal radiation with electromagnetic radiation, understanding how the nature of the surface influences the radiation emitted and absorbed, and understanding qualitatively the relationship between the temperature of an object and the radiation emitted.
(g) describe the greenhouse effect in terms of visible radiation from the Sun and infra-red radiation emitted from the Earth and absorbed and re- emitted from the atmosphere.
(h) compare the use of microwaves and infra-red radiation in long distance communication, including a consideration of geosynchronous satellites, mobile phone technology and intercontinental optical fibre links.
(i) be aware of public concern about claimed health risks associated with mobile phone masts and respond to newspaper and other reports discussing this issue.
(a) apply the term "radiation" to both electromagnetic waves and to energy given out by radioactive materials.
(b) characterise radioactive emissions and short-wavelength parts of the electromagnetic spectrum (ultra-violet, X-ray and -ray) as ionising radiation, able to interact with atoms and to damage cells by the energy they carry.
(c) know that waste materials from nuclear power stations and nuclear medicine are radioactive and some of them will remain radioactive for thousands of years.
(d) observe experiments and/or ICT simulations of experiments to investigate the penetrating power of nuclear radiation and understand that, in making measurements of radiation, an allowance for background radiation must be made.
(e) be aware that the random nature of radioactive decay has consequences when undertaking experimental work, requiring repeat readings to be made or measurements over a lengthy period as appropriate.
(f) distinguish between alpha (), beta () and gamma () radiation in terms of their penetrating power, relate their penetrating powers to their potential for harm and discuss the consequences for the long-term storage of nuclear waste.
(g) be aware of natural and artificial sources of background radiation, respond to information about received dose from different sources (including medical X- rays) and discuss the reasons for the variation in radon levels.
The solar system and its place in an evolving universe
(a) appreciate the range of distance scales appropriate when discussing the universe, from the scale of planets, the Solar System, the Milky Way galaxy and the observable universe.
(b) know that atoms of a gas absorb light at specific wavelengths which are characteristic of the elements in the gas and use data to identify gases from an absorption spectrum.
(c) know that scientists in the nineteenth century were able to reveal the chemical composition of stars by studying the absorption lines in their spectra.
(d) recall that Edwin Hubble's measurements on the spectra of distant galaxies revealed that the wavelengths of the absorption lines are increased and that this "cosmological red shift" increases with increasing distance.
Cells and cell processes
(a) investigate how the development of the microscope (light, electron, laser imaging) influenced the understanding of the structure of organisms and the proposal that the cell is the basic unit of life (cell theory). (Details of subcellular structures or resolution are not needed)
Possible investigations: view objects at different magnifications.
(b) know that microbes include bacteria, viruses, fungi and unicellular algae. Know the structure of a bacterial cell. Bacteria reproduce asexually by dividing into two. Some bacteria are thought to be the earliest forms of life. Know the structure of an algal cell. (References to prokaryote and eukaryote are not required.)
(c) know that yeasts are fungi. Know the structure of a yeast cell. Yeasts reproduce asexually by budding.
(d) investigate the similarities and differences between plant and animal cells and the specialisation that results from being multicellular. Draw and label diagrams of plant and animal cells and understand the function of the following parts: cell membrane, cytoplasm, nucleus; plus cell wall, chloroplast, vacuole.
Possible investigations: view prepared slides of plant and animal cells and tissues; prepare wet mounts of algal or plant cells.
(e) know the basic structure of a virus and that viruses are smaller than bacteria. Viruses can only reproduce inside a host cell. The release of new viruses results in the destruction of the host cell and the released new viruses can then attack new cells.
(f) discuss whether 'cell theory', as proposed in the late 19th century, can still be accepted in the light of the discovery of viruses in the 1950s.
(g) know that different proteins are composed of different amino acids linked together to form a chain which is then folded to form a specific shape. Proteins have a number of important functions e.g. enzymes, hormones and muscle tissue. The specific shape of an enzyme enables it to function. The active site of an enzyme depends on shape which is held by chemical bonds. (Reference to terms primary, secondary, tertiary structure, or type of bonding is not required.)
(h) know that chemical reactions in cells are controlled by enzymes and that enzymes are proteins made by living cells. Enzymes speed up/catalyse the rate of chemical reactions. Each enzyme has its own optimum pH and temperature. Interpret enzyme activity in terms of molecular collisions. Boiling denatures most enzymes by altering their shape. Simple understanding of 'lock and key' modelling is required. Understand that enzymes function by the formation of the enzyme - substrate complex at the active site.
(i) investigate the use of digestive enzymes, lipase's, proteases and carbohydrates in biological washing powders to remove stains from textiles. Use of enzymes enables lower temperatures to be used which requires less energy.
Possible investigations: removal of egg yolk stains from cloth by biological washing powders at different temperatures; investigating the effect of pH on amylase activity.
(j) know that DNA is made up of two long chains of alternating sugar and phosphate molecules connected by bases and that this structure is twisted to form a double helix. Know that there are four bases, A, T, C and G, and that it is the order of these bases which forms a code. This code determines the order in which different amino acids are linked together to form different proteins. Understand complementary base pairing between adenine and thymine, cytosine and guanine and the role of the triplet code during protein synthesis. (Role of RNA is not required.)
Possible investigations: visualisation of DNA structure and function of the code through physical models and computer simulations.
(k) explore information about the discovery of the structure and function of DNA and the process of collaboration needed between scientists, using different techniques, to deduce the mechanism.
(l) understand that cell division, by mitosis, enables organisms to grow, replace worn out cells and repair damaged tissues. The chromosome number remains constant and the genetic composition of the daughter cells is identical to the mother cell. Understand that cell division by meiosis halves the chromosome number for the formation of gametes. (Understanding of the processes of the divisions is not required.)
(m) be able to compare the outcome of a mitotic and a meiotic division. Each mitotic division produces two cells that are genetically identical and have the same number of chromosomes as the mother cell. Each meiotic division produces four cells that are genetically different and have half the number of chromosomes of the mother cell. (Understanding of the stages of the processes is not required.)
(n) know that plants and animals have different patterns of growth and development and consider the advantages and disadvantages. Animals tend to grow to a finite size more so than plants. Animals have a compact growth form whereas in general land plants have a spreading, branched growth form.
(o) know that, in mature tissues cells have generally lost the ability to differentiate into different types of cells. There are some cells, both plant and animal, that do not lose this ability and these are called stem cells. These adult stem cells retain the ability to differentiate into some different types of cells and therefore have potential for replacing damaged tissue, as do embryonic stem cells. Discuss the future potential and possible ethical issues surrounding this technology including the implications for society e.g. the use of embryonic stem cells. Plants have stem cells in their shoot and root tips which retain their ability to differentiate into other cells throughout the life of the plant.
Substances enter and leave cells through the cell membrane
(a) use modelling to show that diffusion is the movement of substances down a concentration gradient including the use of Visking tubing as a model of living material. Consider the role of the cell membrane in diffusion.
(b) understand that diffusion does not require energy and only certain substances pass through the cell membrane in this way, most importantly oxygen and carbon dioxide.
(c) be able to interpret experimental results of Visking tubing experiments in terms of membrane pore and particle size: the pore size is large enough to allow water molecules through but restricts the movement of solute molecules.
(d) investigate experimentally the effect of solute concentration on living plant tissue such as the effect of concentration of blackcurrant squash on osmosis in chipped potatoes.
(e) know that osmosis is the diffusion of water through a selectively permeable membrane, from a region of high water (low solute) concentration to a region of low water (high solute) concentration.
(f) understand active transport as an energy requiring process whereby substances can enter cells against a concentration gradient.
(a) enquire and consider what plants, which consist of cells, require to support life processes and what sources of materials are available.
(b) investigate experimentally the conditions needed for photosynthesis to take place and the factors which affect its rate, including temperature, carbon dioxide and light intensity. Understand these as limiting factors. Computer modelling and simulations should also be used to extend the investigation by exploring further data and graphical interpretations.
(c) be familiar with practical techniques such as use of sodium hydroxide to absorb carbon dioxide, how to test a leaf for the presence of starch, and how oxygen and carbon dioxide sensors and data loggers could be used experimentally to investigate the composition of air in a container housing a plant and varying a variety of factors such as species, illumination level etc.
(d) understand the importance of photosynthesis whereby green plants and other photosynthetic organisms use chlorophyll to absorb light energy and convert carbon dioxide and water into glucose, producing oxygen as a by-product. The chemical reactions of photosynthesis within the cell are controlled by enzymes. Know the word equation for photosynthesis. (Details of the enzymes involved in photosynthesis are not required.)
(e) know the uses made by plant cells of the glucose produced in photosynthesis. Glucose produced in photosynthesis may be respired to provide energy, converted to starch for storage or used to make cellulose and proteins which make up the body of plants.
(a) understand that all cells require a constant supply of energy to carry out cell processes and so enable organs and systems to function, and that energy is released in cells by respiration.
(b) investigate experimentally energy release as heat during respiration,
by germinating peas, including the role of thermos flasks and disinfectants.
(c) know that aerobic respiration occurs in cells when oxygen is available. During aerobic respiration which is (a series of) chemical reactions within the cell controlled by enzymes, glucose and oxygen are used, energy is released and carbon dioxide and water are produced. Some energy is lost as heat. Know the word equation for aerobic respiration.
(d) understand that in the absence of oxygen, anaerobic respiration may occur. This is less efficient than aerobic respiration. In humans energy is released from glucose and lactic acid is produced. An oxygen debt may occur. In yeast, energy is released from glucose and ethanol and carbon dioxide are produced. Know the word equation for anaerobic respiration in human cells and fermentation in yeast. Know that there is less energy released per molecule of glucose in anaerobic respiration than in aerobic respiration. (Reference to ATP is not required.)
(a) question why and understand that during digestion there is a need for the breakdown of large molecules into smaller molecules so they can absorbed for use by body cells.
(b) investigate experimentally the role of enzymes, such as lipase, in digestion including the effect of temperature on enzyme action and the importance of experimental design including biological controls. Understand that boiling denatures enzymes and that enzymes are specific for each type of molecule.
(c) investigate, using Visking tubing as a model gut, how soluble substances can be absorbed through the wall of the small intestine and eventually into the bloodstream, and understand the limitations of the model.
(Knowledge of active transport is not required.)
(d) know that fats, made up of fatty acids and glycerol, proteins, made up of amino acids, and starch (a carbohydrate), made up of a chain of glucose molecules, in our food are insoluble. They are broken down during digestion into soluble substances so that they can be absorbed. Know how to test experimentally for the presence of starch, using iodine solution, glucose using Benedicts reagent and protein using Biuret solution. Use chemical models to show how compounds can be broken down into smaller units.
(e) recognise and label on a given diagram of the human digestive system and associated structures: the mouth, oesophagus/gullet, stomach, liver, gall bladder, bile duct, pancreas, small intestine, large intestine, anus and understand the role of the following organs in digestion: mouth, stomach, pancreas, small intestine, large intestine.
(f) understand how food is moved by peristalsis and know the function of bile, secreted by the liver and stored in the gall bladder, in the breakdown of fats. Possible investigations: observe images (X-ray/CAT scans) showing peristalsis and use of detergent to investigate the action of bile.
(g) understand that body cells need the digested products of fats, carbohydrates and proteins. Fatty acids and glycerol from fats and glucose from carbohydrate provide energy whilst amino acids from digested proteins are needed to build proteins in the body. (Knowledge of lymphatic system is not required.)
(a) understand the need for and purpose of the respiratory system and recognise and label on a given diagram of a vertical section of the human respiratory system: nasal cavity, trachea, bronchi, bronchioles, alveoli, lungs, diaphragm, ribs and intercostal muscles. (Knowledge of pleural membranes is not required.)
Possible investigations: examination/dissection of lungs, bronchi etc.; observation of sections of lung tissue under the microscope.
(b) use a bell jar model to illustrate inspiration and expiration, understand the limitations of this model and be able to explain the mechanism of inspiration and expiration in terms of changes in thoracic volume and pressure brought about by movements of the diaphragm and rib cage.
Possible investigations: computer modelling the human ventilation system.
(c) be able to label on a given diagram of an alveolus and its blood supply: end of bronchiole, wall of alveolus, moist lining of alveolus, wall of capillary, red blood cells and plasma. (The term 'air sac' should not be used.)
(d) understand the differences between inspired and expired air and how gases diffuse between alveolar air and capillaries and know the adaptations of alveoli for gas exchange. Understand the use of lime water to indicate presence of carbon dioxide during investigations and examine data about the gas content of inspired and expired air.
(e) know the function of mucus and cilia and the effects of smoking on cilia and mucus and the consequences for the individual.
(f) investigate the evidence for a link between tar from cigarette smoking and lung cancer and between cigarette smoking and emphysema, and understand the consequences of these conditions.
Possible investigations: 'Going up in smoke'.
(g) discuss the controversy between the sometimes conflicting evidence about the effects of smoking from independent studies and those of vested interest groups. Discuss the need for unbiased interpretation of investigations, scientific validation of data and peer review. Discuss how attitudes to smoking have changed over time as evidence about its effects has been validated by scientists including the conflict between regulation and personal freedom and the cost–benefit considerations.
Biodiversity and environment
(a) use quadrats to investigate the abundance of species e.g. a comparison of different sides of a hedge or mown and unmown grassland.
(b) obtain first hand data to understand how transects can be used to measure changes in the abundance and distribution of species e.g. seashore. Possible investigations: 'Biodiversity in your backyard'.
(c) understand the principles of sampling, the need to collect sufficient data and use of appropriate statistical analysis. (Details of statistical tests are not required.) Understand the principles of capture/recapture techniques including simple calculations on estimated population size.
(d) understand what is meant by biodiversity, the variety or number of different species in an area, and why it is important. Investigate the ways in which biodiversity and endangered species can be protected including issues surrounding the use of legislation. Understand the need for and issues associated with the collection of reliable data and ongoing environmental monitoring. Appreciate how mathematical modelling can be used to analyse environmental interactions and predict trends.
(e) investigate the use of biological control agents and the introduction of alien species and their effects on local wildlife. Understand the issues surrounding the use of biological control agents and how the approach to using this method of control has changed as requirements for detailed research and scientifically based trials and analysis are now more fully understood. Possible investigations: evaluating methods of pest control.
Atomic structure & the periodic table
(a) know that atomic nuclei are comprised of protons and neutrons.
(b) know the relative masses and relative charges of protons, neutrons and electrons.
(c) appreciate that the accepted model of an atom has developed over time as scientists made observations that could not be explained by contemporary ideas, and therefore proposed their own hypotheses to be tested by gathering further experimental evidence.
(d) understand that the atom as a whole has no electrical charge because the number of electrons in the shells is equal to the number of protons in the nucleus.
(e) understand the terms atomic number (proton number) and mass number (nucleon number).
(f) represent the electronic structures of any of the first 20 elements in diagrammatic form
(g) use data to give the number of protons, neutrons and electrons present in an atom.
(h) understand how the electronic structure of any element is related to its position in the Periodic Table (group and period) and understand that the chemical properties of each element is dependent upon its electronic structure.
(i) understand that some elements have two or more isotopes i.e. atoms with the same number of protons but different numbers of neutrons.
(j) know that the mass of an atom of an element is measured on a scale which compares masses of atoms with each other – relative atomic masses (Ar).
(k) be able to calculate the relative molecular (formula) mass (Mr) of a compound from its formula.
Reactions of alkali metals & halogens
(a) investigate the reactions of Group 1 metals with oxygen in the air (corrosion of newly exposed surface and burning) water. Group 7 element in order to establish the trend in reactivity within the group.
(b) describe what is observed when lithium, sodium and potassium react with water.
(c) investigate the reactions of Group 7 elements with iron in order to establish the trend in reactivity within the group.
(d) describe the trends in reactivity within Group 1 and Group 7 and be able to write and interpret word and balanced symbol equations for the above reactions.
(e) investigate the displacement reactions of Group 7 elements in order to confirm the trend in reactivity within the group, be able to make predictions based on this trend and write and interpret word and balanced symbol equations for the reactions.
(f) be able to use flame tests to detect the presence of lithium, sodium and potassium ions.
(g) be able to use silver nitrate solution to detect the presence of chloride, bromide and iodide ions and write and interpret ionic equations for the reactions.
(h) use the above tests in problem-solving situations where they plan and carry out procedures to identify substances.
Chemical bonding, structure & properties
(a) describe the properties of metals, ionic compounds, simple molecular covalent substances and giant covalent substances.
(b) use the 'sea' of electrons/lattice of positive ions structural model for metals to explain their physical properties.
(c) use their understanding of electronic structure to explain how ions are formed, and draw dot and cross diagrams to show how ionic bonding takes place in simple binary compounds formed from Group 1 or 2 elements and elements from Group 6 or 7.
(d) use the accepted structural model for giant ionic structures to explain the physical properties of ionic substances.
(e) use their understanding of electronic structure to explain how covalent bonds are formed, and draw dot and cross diagrams to show the covalent bonding in simple molecules, including examples which contain double bonds.
(f) use the intermolecular bonding structural model for simple molecular structures to explain the physical properties of simple molecular substances.
(g) describe the structures of diamond, graphite and carbon nanotubes.
(h) describe and explain the properties of diamond and graphite, in terms of their bonding and structure, and relate their uses to these properties.
(i) relate the properties and uses of carbon nanotubes to their bonding and structure.
(j) know that thermochromic pigments, photochromic pigments, polymer gels, shape memory alloys and shape memory polymers are known as smart materials and have properties which change reversibly with a change in their surroundings.
(k) know that the above materials change as follows:
thermochromic pigments – change colour with changing temperature
photochromic pigments – change colour with changing light intensity
hydrogels – absorb/expel water and swell/shrink (up to 1000 times their volume) due to changes in pH or temperature
shape memory alloys – regain original shape when heated
shape memory polymers – regain original shape when heated.
(l) relate the uses of smart materials to their properties.
Rate of chemical change
(a) plan and carry out experiments to study the effect of any relevant factor on the rate of a chemical reaction, using appropriate technology e.g. a light sensor and data logger to follow the precipitation of sulfur during the reaction between sodium thiosulfate and hydrochloric acid.
(b) analyse data collected in order to draw conclusions, and critically evaluate the method of data collection, the quality of the data and to what extent the data support the conclusion.
(c) explore the particle theory explanation of rate changes, arising from changing concentration (pressure), temperature and particle size, using a range of sources including textbooks and computer simulations.
(d) understand that a catalyst increases the rate of a chemical change while remaining chemically unchanged itself and explain the effect in terms of the energy required for a collision to be successful.
(e) explain the economic and environmental importance of developing new and better catalysts, in terms of increasing yields, preserving raw materials, reducing energy costs etc.
Basic organic chemistry
(a) Explain the principals involved in the fractional distillation of crude oil i.e. initial heating and evaporation, rising and cooling of vapour and condensation of fractions with similar boiling points at the same level within the column.
(b) Be able to name and write molecular and structural formulae for simple alkanes (C1-C4) and alkenes (C2-C3).
(c) Know the addition reactions of ethene with hydrogen and bromine and write molecular and structural formulae for the products.
(d) Describe and explain the addition polymerisation of ethene and be able to draw the repeating unit for the addition polymers polythene, poly(propene), poly(vinylchloride) and poly(tetrafluoroethene).
(e) Explain the different effect of heating on thermoplastics and thermosets in terms of the forces between their polymer chains.
(a) collect experimental data, and use given data, in order to calculate the formula of a binary compound e.g. magnesium oxide.
(b) calculate the percentage composition of simple compounds.
(c) calculate the masses of reactants or products, from a balanced symbol
equation for a reaction.
(d) be able to calculate the percentage yield of a reaction.
(e) use given bond energy data to calculate the overall energy change for a reaction and to identify whether it is an exothermic or endothermic reaction.
(a) describe in outline the treatment of the public water supply using sedimentation, filtration and chlorination.
(b) appreciate the importance of water conservation in domestic, commercial and industrial contexts.
(c) understand that sea water can be desalinated to supply drinking water and discuss the sustainability of this process on a large scale.
(d) describe and explain the method of separation of water and other miscible liquids, e.g. ethanol, by distillation.
(e) describe how pigments such as inks can be separated using paper chromatography and explain the process in terms of differing solubilities.
(f) analyse chromatogram data to identify components in a mixture and calculate Rf values for a solute.
(g) appreciate that gas chromatography is used by analytical chemists to identify and measure small amounts of certain chemicals e.g. pollutants in water or in the air, banned substances in the blood of athletes.
(h) draw and interpret solubility curves using given data on change of solubility with temperature.
(i) know the causes of hardness in water and distinguish between hard and soft waters by their action with soap.
(j) plan and carry out experiments to determine the type (temporary or permanent) and amount of hardness using soap solution.
(k) analyse data collected in order to draw conclusions, and critically evaluate the method of data collection, the quality of the data and to what extent the data support the conclusion.
(l) explain how the methods of boiling, adding sodium carbonate and ion exchange work to soften water and discuss their advantages and disadvantages.
(m) describe the health benefits of hard water and its negative effects on boilers and water pipes.
(n) appreciate that atomic spectroscopy is used by analytical chemists to identify and find the concentrations of atoms or ions e.g. metal ions in water samples and biological tissues.
Simple electrical circuits
(a) use voltmeters and ammeters to measure the voltage across and current through electrical components in electrical circuits.
(b) know that, for components arranged in parallel, the voltage is the same across all components and the total current is equal to the sum of the currents through the individual components and appreciate how this relates to mains domestic circuits.
(c) know that the current is the same for components in series.
(d) use a circuit, which includes a variable resistor, to investigate how current changes with voltage for a component and recall the relationship for resistor (or wire) at constant temperature and a filament lamp.
(e) understand qualitatively, the relationship between current, voltage and resistance.
(f) select and use the equation: current voltage ; I V
power = voltage current; P = VI and
power = current2 resistance; P = I 2R.
resistance R (g) select and use the equations:
Distance, speed and acceleration
(a) describe motion using speed, acceleration, velocity-time and distance-time graphs.
(b) select and use the equations: speed distance , and
acceleration[or deceleration] change in velocity ; a v
(c) use velocity-time graphs to determine acceleration and distance travelled.
The effect of forces
(a) investigate experimentally, e.g. using an air track and data logger, the effect of forces on the motion of an object.
(b) understand the concept of inertia, that mass is an expression of the inertia of a body and recall, understand and apply Newton's first law of motion.
(c) understand qualitatively how the momentum of a body depends upon its mass and its velocity, and select and use the equation:
momentum = mass velocity ; momentum = mv
(d) understand that unbalanced forces produce a change in a body's motion and that the acceleration of a body is directly proportional to the resultant force and inversely proportional to the body's mass.
(e) select and use Newton's second law of motion in the forms: resultant force = mass acceleration; F = ma
Force change in momentum ; F p
(f) distinguish between the weight and mass of an object, use the approximation that the weight of an object of mass 1 kg is 10 N on the surface of the earth and use data on gravitational field strength in calculations involving weight and gravitational potential energy.
(g) use knowledge of forces and their effects to explain the behaviour of objects moving through the air, including the concept of terminal speed.
Interactions between objects
(a) state and use Newton's third law of motion.
(b) know that when a force acts on a moving body, energy is transferred although the total amount of energy remains constant.
(c) select and use the equation:
work = force distance moved in the direction of the force ; W = Fd
appreciating that work is a measure of the energy transfer, i.e. that work = energy transfer (in the absence of thermal transfer)
(d) appreciate that an object can possess energy because of its motion (kinetic energy) or position (potential energy)
(e) select and use the equations: kinetic energy mass velocity ;KE12mv2
(f) investigate work and energy transfer experimentally, e.g. model crumple zones and using catapults to accelerate vehicles.
(g) apply the principles of forces and motion to the safe stopping of vehicles, including knowledge of the terms reaction time, thinking distance, braking distance and overall stopping distance and discuss the factors which affect these distances.
(h) apply the principles of forces and motion to an analysis of safety features of cars e.g. air bags and crumple zones.
(i) apply their knowledge of the physics of motion together with presented data and opinions to discuss traffic control arising from (g) and (h) above, e.g. the need for speed limits and seat belts.
change in = mass gravitational change
potential energy field strength in height ; PE = mgh.
The half-life of radioactive materials & the nature of nuclear radiations
(a) be aware of the random nature of radioactive decay and model the decay of a collection of atoms using a constant probability of decay, e.g. using a large collection of dice, coins or a suitably programmed spreadsheet.
(b) plot or sketch decay curves for radioactive materials, understand that a given radioactive material has a characteristic half life and determine the half life of a material from the decay curve.
(c) express the activity of a radioactive source in Becquerel.
(d) perform simple calculations involving the activity and half life of radioactive materials in a variety of contexts, e.g. carbon dating.
(e) respond to information describing uses of radioactive materials, relating to the half life, penetrating power and biological effects of the radiation e.g. radioactive tracers and cancer treatment.
(f) identify alpha radiation as a helium nucleus, beta radiation as a high-energy electron and gamma radiation as electromagnetic, and recall and use the
symbols 4 He, 0e for alpha and beta particles. 2 -1
(g) know that radioactive emissions from unstable atomic nuclei arise because of an imbalance between the numbers of protons and neutrons.
Nuclear structure, fission and fusion
(a) understand the terms nucleon number(A), proton number(Z) and isotope and relate them to the number of protons and neutrons in an atomic nucleus.
(b) understand and use nuclear symbols of the form ZA X in the context of transformations including radioactive decay, nuclear fission and nuclear
fusion, and use data to produce and balance nuclear equations.
(c) know that the absorption of slow neutrons can induce fission in 235 U nuclei,
releasing energy, and that the emission of neutrons from such fission can lead to a sustainable chain reaction.
(d) understand the roles of the moderator and control rods in a nuclear fission reactor.
(e) appreciate that nuclear fission products are unstable with a wide range of half lives.
(f) know that high energy collisions between light nuclei, especially isotopes of hydrogen, can result in fusion which releases energy.
(g) discuss the problems of containment in fission and fusion reactors including neutron and gamma shielding and pressure containment infusion reactors and maintaining a high temperature in fusion reactors.
PLANTS, WATER AND NUTRIENTS
(a) understand why water is important to plants and its use in photosynthesis, transport of minerals and support. (Reference to pressure potential is not required.) Possible investigations: effects of lack of water on plant support.
(b) investigate water loss in plants, for instance using a bell jar, and use of a simple potometer to investigate the effect of different environmental conditions on the rate of transpiration from a plant cutting.
(c) observe root hairs and understand their significance increasing the area for absorption. Understand the role of osmosis in the uptake and movement of water through a plant and understand that mineral salts are taken up by root hairs by active transport. Possible investigations: tracking active uptake of minerals by plant roots.
(d) carry out an investigation into the movement of a dye through a flowering plant and know the role of xylem in transport of water within plants. Understand the role of transpiration in the movement of water through a plant.
(e) recognise and label on a given diagram of a T.S. leaf: cuticle, epidermis, stomata, palisade layer, spongy layer, xylem and phloem. Structure of stomata to include guard cells and stoma. Understand that stomata can open and close to regulate transpiration. (No details of the mechanism of opening and closing are required.) Possible investigations: investigate distribution of stomata using nail varnish replicas and examine photomicrographs of plant structure.
(f) investigate plant nutrient requirements and the effects of deficiencies on plant growth. Understand that lack of nitrates results in poor growth, deficiency of potassium results in yellowing of the leaf and deficiency of phosphate results in poor root growth and understand the use of KPN fertilisers.
(g) know that phloem carries sugar from the photosynthetic areas to other parts of the plant. Sugar is moved to other parts of the plant for use in respiration and converted into starch for storage. The transport of sugar is not fully understood so it is still being investigated by plant scientists. (Knowledge of mass flow is not required.)
Blood and circulation
(a) investigate and discuss the scientific approach of Harvey, in the 17th century, which showed, beyond all reasonable doubt, that blood circulates around the mammalian body.
(b) be able to draw and label diagrams of a white blood cell (phagocyte only) and a red blood cell and know the differences between these cells; know the functions of the four main parts of the blood: red cells, platelets, plasma, white cells. (Details of haemoglobin or clotting mechanism are not required.)
(c) know that a double circulatory system involves one to the lungs and one to the other organs of the body, and be able to recognise this on a diagram. Only the names of the following blood vessels are required: pulmonary artery, pulmonary vein, vena cava and aorta.
(d) know that the heart pumps blood around the body and that it is made of muscle. Know that the heart has its own blood supply through the coronary vessels and that the blood flows to the organs through arteries and returns to the heart through veins. (Structure of arteries and veins is not required.)
(e) recognise and label on a given diagram of the heart: the left and right atria and ventricles, valves, pulmonary artery, pulmonary vein, aorta and vena cava. (Names of individual valves are not required.)
(f) be able to describe the passage of blood through the heart including the functions of the valves in preventing backflow of blood.
(g) observe a dissected/model of the heart, to include coronary arteries and internal structure, and examine prepared slides of blood smears. Possible investigations: structure of a lamb’s heart or model; effect of exercise on heart rate.
(h) know that in the organs blood flows through very small blood vessels called capillaries. Substances needed by cells pass/diffuse out of the blood to the tissues, and substances produced by the cells pass/diffuse into the blood, through the walls of the capillaries. The thin walls of the capillaries are an advantage for diffusion. Capillaries form extensive networks so that every cell is near to a capillary carrying blood.
(a) recognise and label on a given diagram of a vertical section through the eye the following parts and understand their functions: sclera, cornea, pupil, iris, lens, choroid, retina, blind spot and optic nerve. Possible investigations: observe changes in pupil size under different light intensities.
(b) understand that the brain, spinal cord and nerves form the nervous system and the central nervous system consists of the brain and spinal cord.
(c) know that some responses in animals are reflex actions. These reactions are fast and automatic and some are protective, as exemplified by the withdrawal reflex, blinking and pupil size. Possible investigations: knee jerk reflex (which helps to keep us upright).
(d) know that a reflex arc involves stimulus, receptor, coordinator and effector. Recognise and label a given diagram of a reflex arc to show: receptor, sensory neurone, relay neurone in spinal cord, motor neurone, effector and synapses.
Role of the kidney in homeostasis
(a) know that the kidneys regulate the water content of the blood and remove waste products from the blood and understand why this is necessary.
(b) recognise and label a given diagram of the human excretory system to show kidneys, renal arteries, renal veins, aorta, vena cava, ureters, bladder, urethra and be able to indicate the direction of blood flow in the blood vessels associated with the kidney.
(c) recognise and label a given diagram of a section through a kidney to include: renal artery, renal vein, cortex, medulla, pelvis, ureter. Know the position of nephrons. Possible investigations: observe gross structure of a section through a kidney to locate the cortex, medulla, pelvis and ureter.
(d) recognise and label a given simplified diagram of a nephron and its associated blood supply to show: capillary knot, Bowman's capsule, tubule, collecting duct, capillary network, arteriole to and from capillary knot.
(e) interpret data about changes in the level of substances present due to passage through the kidney, understand the process of filtration under pressure and know that selective reabsorption of glucose, some salts, and much of the water takes place in the tubule.
(f) know that the waste, a solution containing urea and excess salts called urine, passes from the kidneys in the ureters to the bladder where it is stored before being passed out of the body. Understand that the presence of blood or cells in the urine indicates disease in the kidney.
(g) know that the kidneys regulate the water content of the blood by producing dilute urine if there is too much water in the blood or concentrated urine if there is a shortage of water in the blood. Role of anti-diuretic hormone (ADH).
(h) know that kidney failure may be treated by dialysis. Understand how a dialysis machine works.
(i) know that a diseased kidney may be replaced by a healthy one by transplant from a donor of a similar 'tissue type' to the recipient. The donor kidney may be rejected by the body, attacked by the immune system, unless drugs are taken which suppress the immune response.
(j) understand the advantages and disadvantages of the use of dialysis and transplants and discuss the ethical issues involved.
Microorganisms and disease
(a) understand that most microorganisms are harmless and many perform vital functions however some microorganisms, called pathogens, cause diseases. Intact skin forms a barrier against microorganisms. The body also defends itself by: blood clots to seal wounds; white cells in the blood ingest microorganisms and produce antibodies and antitoxins. Pathogens must also compete with the body's natural population of microorganisms.
(b) understand that vaccination can be used to protect humans from infectious disease. Discuss the deductive process and possible issues surrounding the work by Jenner on vaccination. Consider the factors influencing parents in decisions about whether to have children vaccinated or not, including the need for sound scientific evidence and the effect of the media and public opinion. Understand that science can only provide a statistically based ‘balance of probability’ answer to such issues.
(c) know that an antigen is a molecule that is recognised by the immune system. Foreign antigens trigger a response by some white blood cells, lymphocytes, which secrete antibodies specific to the antigen. Know the function of antibodies.
(d) know that a vaccine contains antigens (or parts of antigens) derived from a disease-causing organism. A vaccine will protect against infection by that organism by stimulating the white blood cells to produce antibodies to that antigen. Vaccines may be produced which protect against bacteria and viruses.
(e) assess data showing how, after an antigen has been encountered, memory cells remain in the body and antibodies are produced very quickly if the same antigen is encountered a second time. This memory provides immunity following a natural infection and after vaccination. The response is highly specific to the antigen involved.
(f) understand why most people suffer from measles only once, but could suffer from flu many times during their lives.
(g) investigate the effect of penicillin on bacteria growing on agar plates. Antibiotics, including penicillin, were originally medicines produced by living organisms, such as fungi. Antibiotics help to cure bacterial disease by killing the infecting bacteria or preventing their growth. Possible investigations: investigate the effect of antimicrobial agents in cut wells, chimneys or filter paper discs on bacteria growing on agar plates.
(h) understand that antibiotics may kill some bacteria but not viruses. Some resistant bacteria, such as MRSA, can result from the over use of antibiotics. Know effective control measures for MRSA.
Micro-organisms and their applications
(a) understand the safe use of basic aseptic techniques involved in inoculating, plating and incubating microorganisms. Possible investigations: aseptic techniques; incubating and viewing plates; pouring an agar plate.
(b) investigate the presence of bacteria in milk using agar plates. Understand the link between the number of bacterial colonies on the agar and the number of bacteria in the original sample. Possible investigations: investigate bacterial numbers in different types of milk; making yoghurt from a starter culture.
(c) investigate experimentally and explore information about the effect of temperature on the growth of bacteria and understand its application in food storage. (Growth curve is not required.) Possible investigations: investigate bacterial numbers in food or milk kept in different storage conditions.
(d) know that the fungus Penicillium is grown industrially in a fermenter and understand the factors which influence its growth. The penicillin is extracted from the surrounding medium by filtration.
(e) know that there are advantages to using microorganisms for food production e.g. in the production of mycoprotein.
(f) understand that microorganisms have an important role in decay and also have potential benefits for the environment. Investigate information about the uses of microorganisms, research and methods involved, such as cleaning up pollution, breaking down waste such as some plastics and producing biofuels.
Additional organic chemistry
(a) investigate patterns in the molecular formulae of alkanes, alkenes and alcohols.
(b) be able to name and write molecular and structural formulae for straight chain alkanes (C1-C5) and alkenes (C2-C3).
(c) be able to write structural formulae for the chain isomers of C4H10 and C5H12.
(d) be able to name and write molecular and structural formulae for alcohols (C1-C3), including the positional isomers of propanol.
(e) understand that enzymes are catalysts produced by living cells and investigate how the rates of enzyme catalysed reactions are affected by temperature.
(f) describe how ethanol is made from sugars by the process of fermentation, the conditions used and the method of obtaining ethanol from the reaction mixture.
(g) be able to write and interpret word and balanced symbol equations to represent fermentation.
(h) know that ethanol is present in alcoholic drinks, and discuss the social and economic impact of these drinks.
(i) know that ethanol is used as a solvent and as a fuel.
(j) understand the social, economic and environmental factors that affect the development of ethanol as a fuel.
(k) apply their understanding of the fire triangle to methods of fire prevention.
(l) know that ethanol undergoes microbial oxidation to ethanoic acid (vinegar).
(m) know that ethanoic acid is a weak acid and compare its reactions with those of dilute sulphuric acid.
Reversible reactions, industrial processes & important chemicals
(a) describe how ammonia is made by the reversible reaction of nitrogen and hydrogen in the Haber process and be able to write and interpret the word and balanced symbol equation for the reaction.
(b) know that an iron catalyst is used during the Haber process, and explain the choice of temperature and pressure employed and the importance of recycling unreacted nitrogen and hydrogen.
(c) know that ammonia can be oxidised to give nitric acid.
(d) describe the stages in the Contact process for the manufacture of sulfuric acid and know that vanadium(V) oxide is used as a catalyst for the reversible formation of sulfur trioxide.
(e) be able to write and interpret word and balanced symbol equations for the formation of sulfur trioxide.
(f) know how nitrogenous fertilisers such as ammonium sulfate and ammonium nitrate are obtained by neutralising ammonia solution with sulfuric acid and nitric acid respectively.
(g) describe and explain the benefit of nitrogenous fertilisers for crop growth and theproblems that arise when they are washed into rivers.
(h) evaluate the advantages and disadvantages of using nitrogenous fertilisers for individuals, communities and the environment.
(i) know that concentrated sulphuric acid can remove the elements of water from substances such as sugar and hydrated copper(II) sulphate.
Titration & mole calculations
(a) know that the relative molecular (formula) mass of a compound, in grams, is equivalent to one mole of that substance.
(b) be able to calculate the molar mass of a compound whose formula is given.
(c) be able to convert the mass to amount of a substance in moles and vice versa, given formulae and relative atomic and molecular (formula) masses.
(d) be able to calculate the concentration of a solution in mol dm3, given the amount of substance and volume of solution.
(e) be able to calculate the number of moles or mass of a substance in a solution of given volume and concentration (mol dm3).
(f) be able to carry out a titration using an indicator and use titration data to compare the relative concentrations of solutions.
(g) perform calculations involving neutralisation reactions in solution, using a balanced equation.
(h) use titration method to prepare pure solutions of soluble salts, such as sodium chloride, from alkalis and evaporate to give crystals.
(a) investigate the thermal decomposition of the carbonates of calcium, copper and sodium and be able to write and interpret word and balanced symbol equations for any reactions that occur.
(b) investigate the reaction of quicklime with water to produce slaked lime and be able to write and interpret word and balanced symbol equations for the reaction.
(c) be able to write word and balanced symbol equations for the reaction of limewater and carbon dioxide.
(d) know that limestone is used in the production of iron and steel, in road- building, to neutralise soil acidity and to make cement.
(e) evaluate the social, economic and environmental effects of limestone quarrying.
(a) be able to describe chemical tests for the gases hydrogen, oxygen, carbon dioxide and ammonia.
(b) be able to use flame tests to distinguish between Na+, K+, Ca2+ and Cu2+ ions and describe the test to identify NH4+ ions by addition of NaOH(aq).
(c) be able to describe the precipitation reactions of NaOH(aq) with aqueous Fe2+, Fe3+ and Cu2+ and write and interpret word and balanced symbol equations for the reactions that occur (including ionic equations).
(d) appreciate that atomic spectroscopy is used to identify and find the concentrations of atoms or ions e.g. by a forensic scientist trying to identify a paint sample.
(e) be able to describe chemical tests to identify Cl, Br, I, CO32 and SO42 and write and interpret word and balanced symbol equations for the reactions that occur (including ionic equations for precipitation reactions).
(f) be able to describe chemical tests used to distinguish between an alkene, an alcohol and a carboxylic acid.
(g) use the above tests in problem-solving situations where they plan and carry out procedures to identify substances.
(h) appreciate that infrared spectroscopy is used to identify the presence of certain bonds in organic molecules and use data to identify alkanes, alkenes, alcohols and carboxylic acids.
(i) be aware that the breathalyser used to take readings of alcohol concentration in the breath is an infrared-based test.
(a) investigate the magnetic fields and recall the field patterns of bar magnets, straight wires, plane coils and solenoids.
(b) investigate the motor effect and relate the direction of the force on a current-carrying wire to the directions of the current and magnetic field.
(c) interpret and label a diagram of a simple d.c. motor, predicting its direction of rotation and understand qualitatively the effect on increasing the current, magnetic field strength and number of turns.
(d) investigate the conditions in which a current is induced in circuits by changes in magnetic fields and the movement of wires.
(e) use knowledge of electromagnetic induction to explain the operation of a simple a.c. electric generator including the factors upon which its output depends.
(f) relate the direction of the induced current in a generator to the direction of the magnetic field and the direction of rotation of the coil.
(g) investigate model transformers experimentally, e.g. using linked C-cores or demountable transformers, know qualitatively how the output voltage depends upon the number of turns on the coils and explain their operation qualitatively by reference to electromagnetic induction.
(h) select and use the equation: V1 N1
V2 N2 in the context of 100% efficient step-up and step-down transformers, and the equation: P = VI to the primary and secondary coils.
The properties of waves and their use in investigating the structure of the earth
(a) distinguish between transverse and longitudinal waves in terms of the direction of oscillation and the direction of propagation, appreciating that sound waves and P-waves are longitudinal and that electromagnetic waves and S-waves are transverse.
(b) investigate experimentally the refraction of light at a plane boundary and the conditions under which total internal reflection occurs.
(c) understand how endoscopes and optical fibres rely on total internal reflection for their operation. [NB monomode optical fibres will not be examined.]
(d) explain refraction in terms of the speed of waves on either side of a refracting boundary.
(e) draw and interpret diagrams of plane waves being reflected or refracted at plane boundaries, e.g. as shown in a ripple tank.
(f) understand the properties of seismic P-waves, S-waves and surface waves, in terms of their nature, speed and ability to penetrate different materials.
(g) appreciate qualitatively how the speed of a wave depends upon the density and rigidity of the material through which it propagates.
(h) appreciate that earthquakes result from P, S and surface waves generated by the release of energy stored in rocks on either side of a fault.
(i) interpret simplified seismic records, including the identification of the lag time between the arrival of the P and S waves and use the seismic records from several stations to locate the epicentre of an earthquake.
(j) interpret and sketch diagrams of the path of P and S-waves through the earth, relating their paths to the properties of the Earth's mantle and core.
(k) know how the study of seismic records, including the identification of P and S-wave shadow zones, has enabled geo-physicists to investigate the structure of the earth, leading to a model of a solid mantle and a liquid core.
(a) select and use the equation speed distance for unaccelerated motion/ time
(b) appreciate that the motion of objects can be modelled using the equations: x 12 ( u v ) t v u at v2 u2 2ax x ut 1 at2 2 understand the condition under which these equations are valid and select and use these equations to solve problems including simple questions involving motion under gravity, without frictional forces.
(c) explore experimentally, or using IT simulations, the collisions of objects under conditions in which externally applied forces are negligible, to develop an appreciation of the significance of the momentum of a body.
(d) recall the law of conservation of momentum and relate it to Newton's third law of motion.
(e) appreciate the law of conservation of momentum qualitatively and use it quantitatively to perform calculations involving collisions or explosions, including selecting and using the equation: kineticenergy 1 mv2 2 to compare the kinetic energy before and after an interaction.
The origin of the chemical elements
(a) recall that the Big-Bang model suggests an initial elemental composition for the universe of hydrogen (roughly 75%) and helium (roughly 25%) with very small quantities of other light elements.
(b) recall the main observable stages in the life-cycle of stars of different masses, using the terms brown dwarf, red dwarf, main sequence, white dwarf, red giant, supernova, neutron star and black hole.
(c) appreciate that the stability of stars depends upon a balance between gravitational force and a combination of gas and radiation pressure.
(d) appreciate that main sequence stars generate their energy by the fusion of hydrogen to helium, according to the equation 4 1 H 4 He + 2 0 e 121 where 01e is a positron, the antiparticle of an electron which will subsequently annihilate together with an electron, releasing further energy . Recall of details of the fusion processes, either the proton-proton chain or the CNO cycle, will not be required, but candidates may be required to interpret information about nuclear reactions in stars which may be presented in the form of nuclear equations.]
(e) know that Hoyle and colleagues were able to use the results of nuclear research to account for the production of all elements heavier than helium in the process of nucleosynthesis in stars.
(f) use information to construct and interpret nuclear equations in the context of fusion processes in stars.
(g) describe the processes in post main-sequence stars in terms of the production of increasingly heavier elements, up to iron-56, in shells around the core of a star and recall that the limit of this depends upon the mass of the star.
(h) recognise a simplified binding energy per nucleon curve and understand its relationship to energy release in nuclear fission and fusion.
(i) recall that in fission and fusion processes which release energy, the mass of the products is less than that of the reactants, and that the energy release can be calculated using the mass-energy relationship: E = mc2
(j) relate the final stages in the life cycle of solar-mass and giant stars to the cessation of nuclear fusion and the existence of heavier elements in the interstellar medium to their ejection during the death of massive stars.
(k) appreciate that the production by fusion of elements heavier than iron requires energy, that these elements, including uranium, are only produced from the energy released during the gravitational collapse of massive stars and that our ability to use uranium in a fission reactor is because of the release of this element in a supernova.