4.4 Explaining change 4.4.1 The Earth’s atmosphere Spec ref. Summary of the specification content Learning outcomes What most candidates should be able to do Suggested timing (hours) Opportunities to develop Scientific Communication skills Opportunities to practical and enquiry skills Self/peer assessment Opportunities and resources Reference to past questions that indicate success 4.4.1.1 Evidence for the early atmosphere is limited because of the time scale of 4.6 billion years. One theory suggests that during the first billion years of the Earth’s existence there was intense volcanic activity, which released gases that formed the early atmosphere and water vapour that condensed to form the oceans. At the start of this period the Earth’s atmosphere may have been like the atmospheres of Mars and Venus today, consisting mainly of carbon dioxide with little or no oxygen gas. Volcanoes also produced nitrogen, gradually built up in the atmosphere, and there may have been small proportions of methane and ammonia. Students should be able to, given appropriate information, interpret evidence and evaluate different theories about the Earth’s early atmosphere. 1.5 Describe the theory of the evolution of the Earth’s early atmosphere in 60 seconds. Represent changes in the Earth's atmosphere over time in a diagram. Compare the Earth’s atmosphere to that of Mars and Venus. Extended writing: explain how and plants have caused the concentrations of oxygen in the atmosphere to increase. Students make a presentation in they explain how algae and plants have caused the concentrations of carbon dioxide in the atmosphere to decrease. Describe how sedimentary rocks formed and locked up carbon dioxide. How have sedimentary rocks helped scientists piece together the history of the Earth's atmosphere? What are isotopes and why are they useful to geologists? Why has the proportion of CO2 in the atmosphere decreased over time? What is a mass spectrometer and what is it used for? Sedimentary rocks in SW Greenland are 3.8 million years old. What does this tell us about the Earth? What happened to oxygen in the Earth's early atmosphere? Video clips: YouTube: YouTube: about ancient volcanoes, climate etc: Teachit Science resource Teachit Science resource
natural gas and oil. 4.4.1.2 The element carbon is as carbon dioxide in the atmosphere, dissolved in the water of the oceans, as calcium carbonate in sea shells, in fossil fuels and in limestone rocks, and as carbohydrates and other large molecules in all living organisms. Carbon cycles through the environment by processes that include photosynthesis, respiration, combustion of fuels and the industrial uses of limestone. Life depends on photosynthesis in producers such as green plants, which make carbohydrates from carbon dioxide in the air. Animals feed on plants, passing the carbon compounds along food chains. Animals and plants respire and release carbon dioxide back into the air. Describe the carbon cycle. Interpret and explain the processes in diagrams of the carbon cycle. Explain the importance of the carbon cycle to living things. Explain the role of microorganisms in cycling materials through an ecosystem. 1 Discussion questions Link the 7 processes of life to the carbon cycle What are detritivores? If the rate of decay slowed to almost zero what effect would this have on us and on the carbon cycle? What's my role in the carbon cycle? WS 1.2 Draw and interpret diagrams to represent the main stores of carbon and the flows of carbon between them in the cycle. This topic links with 4.4.2 (Ecosystems and biodiversity). Give of data for changes in; atmospheric CO2, CO2 in seawater and pH of seawater, over time (eg Students plot graph(s), describe and explain any correlations and use graphs to predict changes over the next decade. Investigate organisms in leaf litter. Use keys to identify. Students research maggots in forensic science. Teachit Science resources , and Hand lenses, binocular microscopes, white trays, tweezers, specimen tubes, identification charts.
Decay of dead plants and animals by microorganisms returns carbon to the atmosphere as carbon dioxide and mineral ions to the soil. 4.4.1.3 Greenhouse gases in the atmosphere maintain temperatures on Earth high enough to support life. They allow short wavelength radiation from the Sun to pass through the atmosphere to the Earth’s surface but absorb the outgoing long wavelength radiation from the Earth’s surface, causing an increase in temperature. Water vapour, carbon dioxide and methane are greenhouse gases that increase the absorption of outgoing, long wavelength radiation. Describe the greenhouse effect in terms of the interaction of radiation with matter. 1 Ask students to the greenhouse effect (provide them with a range of materials such as (fruit) netting, string, sticky notes, marbles/beads of different sizes, etc). Investigate changing conditions on the effect of temperature in model greenhouses (use plastic bottles). Research methane as a greenhouse gas. How can temperature data be obtained from ice core samples? Video clips: YouTube: YouTube: (long video) NASA JPL greenhouse investigation - 4.4.1.4 Human activities that involve burning fossil fuels (coal, oil and gas) for generating electricity, transport and Describe how greenhouse gases are produced. 1 Discussion question – is climate change new? Use the internet to obtain data for concentrations of greenhouse gases. Teachit Science resource
industry all add carbon dioxide to the atmosphere. These activities have led to a large rise in the concentration of carbon dioxide in the air over the last 150 years. Over the same time the average temperature of the surface of the Earth has risen. The scientific consensus is that this is more than correlation and that the rise in greenhouse gas concentrations has caused the rise in temperature. Climate describes the patterns of weather in different parts of the world. Climate change is shown by changes to patterns in measures of such things as air temperature, rainfall, sunshine and wind speed. Scientists analyse data on climate change using computer models based on the physics that describes the Evaluate the use of models for predicting climate change. Evaluate the quality of evidence in a report about global climate change given appropriate information Describe uncertainties in the evidence base. Recognise the importance of peer review of results and of communicating results to a wide range of audiences. Interpret climate graphs from different parts of the world. WS 1.6 Explain the importance of scientists publishing findings and theories so that they can be evaluated critically by other scientists. WS 1.6 Understand that the scientific consensus about global warming and climate change is based on systematic reviews of thousands of peer reviewed publications. WS 1.3 Explain why evidence is uncertain or incomplete in a complex context. MS 2c, 4a Extract and interpret information from charts, graphs and tables. MS 2h Evaluate the reliability of the data available on the internet. Research the process of peer review in reporting results/data. Video clip: YouTube: FLIR Making the invisible visible video:
movements of mass and energy in the climate system. Many complex changes on Earth affect the climate and detailed data about the scale of the changes is not available from all over the world. Also, when predicting climate change, scientists have to make assumptions about future greenhouse gas emissions. This means that there are uncertainties in the predictions. Use orders of magnitude to evaluate the significance of data. 4.4.1.5 Consequences of global warming and climate change include: sea-level rise loss of habitat changes to weather extremes changes in the amount, timing and distribution of rainfall temperature and water stress for humans and wildlife Identify the effects of global warming. Explain the effects of climate change. Describe the scale, risk and environmental implications of global climate change. Describe how emissions can be reduced. Suggest the consequences of the reductions on the 1 Students research the effects of global warning and climate change and prepare a class presentation. Students use the carbon as a starting point to suggest ways that the effects of climate change can be mitigated. Discussion questions: Do vegetarians contribute less to climate change? Using a globe identify capital cities. How many are located on the coast or river mouths? Students research the problems faced by Pacific island states such as the Marshall Islands. Research question - are tropical storms becoming stronger and/or more frequent? Video clips: WWF website
changes in the distribution of species changes in the food producing capacity of some regions Steps can be taken to mitigate the effects of climate change by reducing the overall rate at which greenhouse gases are added to the atmosphere. Examples of mitigation include: using energy resources more efficiently renewable sources of energy in place of fossil fuels (see 4.8.2, Resources of materials and energy) reducing waste by recycling stopping the destruction of forests regenerating forests developing techniques to capture and store carbon Earth, atmosphere and everyday life. How could you prove growing trees remove CO2 from the atmosphere? Who should pay farmers to regenerate forests on their land? WS 1.4 In the context of climate change, evaluate associated economic and environmental implications; and make decisions on the evaluation of evidence and arguments. Write a persuasive newspaper article for the building of a new, local wind farm. Write letters of disagreement from readers. Students decide the benefits (include data) of recycling and present their ideas as a 'sales pitch'. Collect data on the greenhouse gas emissions of a variety of countries. How much should each country be responsible for the consequences of global warming? What is a 'porous liquid' and why are scientists excited about it?
dioxide released from fossil fuel power stations. 4.4.1.6 The combustion of is a major source of atmospheric pollutants that can be harmful to health and the environment. Carbon monoxide is formed by the incomplete combustion of hydrocarbon fuels when there is not enough air. Carbon monoxide is a toxic gas that combines very strongly with haemoglobin in the blood. At low doses it puts a strain on the heart by reducing the capacity of the blood to carry oxygen. At high doses it kills. Sulfur dioxide is produced by burning fuels that contain some sulfur. These include coal in power stations and some diesel fuel burnt in ships and heavy vehicles. Predict the products of combustion of a fuel appropriate information about the composition of the fuel and the conditions in which it is used. Explain the problems caused by increased amounts of pollutants in the air. Describe the effect of the following products: carbon monoxide on the human body sulfur dioxide and oxides of nitrogen on acidity of rain water sulfur dioxide and oxides of nitrogen on respiratory system 1 word equations for complete and incomplete combustion. Use equations to describe the reactions in terms of reactants, products made and number of each present. Should carbon monoxide monitors in every home be compulsory? Explain why the following can be produced in combustion: carbon dioxide carbon monoxide soot water vapour sulfur dioxide oxides of nitrogen. WS 1.4 Describe, explain or evaluate ways in which human activities affect the environment. Why is carbon monoxide particularly dangerous? Why do children and young people succumb more readily to carbon monoxide poisoning? How do CO monitors compare to smoke alarms? CO detectors use one of three types of sensor. Students investigate the types and decide which branch of Science they stem from. Students view graphs showing acid rain emission 1960s–present day. Interpret the graphs and suggest/research reasons for the patterns. Video clips YouTube: YouTube:
Sulfur dioxide turns to sulfuric acid in moist air. Oxides of nitrogen are produced by the reaction of nitrogen and oxygen from the air at the high temperatures involved when fuels are burned. Sulfur dioxide and oxides of nitrogen cause respiratory problems in humans and cause acid rain. Acid rain damages plants and buildings. It also harms living organisms in ponds, rivers and lakes. Particulates in the air include soot (carbon) from diesel engines and dust from roads and industry. The smaller particulates can go deep into people’s lungs and cause damage that can lead to heart disease and lung cancer. particulates on human global dimming particulates on human health problems. What is causing acidification of the world's oceans?
provide habitats for many living organisms. 4.4.1.8 Water that is safe to drink is called potable water. Potable water is not pure water in the chemical sense because it contains dissolved substances. The methods used to produce potable water depend on available supplies of water and local conditions. In the UK, rain provides water with low levels of dissolved substances (fresh water) that collects in the ground and in lakes and rivers and most potable water is produced by: choosing an appropriate source of fresh water passing the through filter beds to remove any solids sterilising to kill microbes. Sterilising agents used for potable water include Define the terms potable water and pure water. Explain the differences between the two terms. Describe the differences in treatment of ground water and salty water. 1 Discussion question – what does 'potable' mean? What are the similarities and differences between potable water and pure water? Students find out about solar disinfection and outline the advantages and disadvantages of water purification at the point of use. How can we know that is safe to drink? Make from information leaflets about sewage treatment processes and use to draw a diagram to summarise. How do reed beds work as water treatment systems? WS 1.4 Explain everyday and technological applications of science; evaluate associated Required practical 11: analysis and purification of water samples from different sources, including pH, dissolved solids and distillation. Chemistry AT2, 3 and 4 Students design a sustainable drainage system (SuDS), eg for their school. Links to reducing risk of flooding and preventing water pollution. On average, adults produce 200 g faeces/day; a stool is 75% water. Students use these figures to make estimations regarding the quantity produced by a local conurbation over given periods of time. Video clip YouTube: Resources for schools - Several companies provide resources for schools regarding sewage treatment, eg clip YouTube: Information about SuDS.
screening and grit removal sedimentation to produce sewage sludge and effluent anaerobic digestion of sewage sludge aerobic biological treatment of effluent. 4.4.2 Ecosystems and biodiversity Spec ref. Summary of the specification content Learning outcomes What most candidates should be able to do Suggested timing (hours) Opportunities to develop Scientific Communication skills Opportunities to apply practical and enquiry skills Self/peer assessment Opportunities and resources Reference to past questions that indicate success 4.4.2.1 An ecosystem is made up of all the living organisms in a particular environment together with the non-living components such as soil, air and water. A habitat is where a particular organism lives in Understand and use the terms ecosystem, community, competition, habitat, interdependence. 1 Look at pictures of different habitats and think-pair-share factors that affect the survival of organisms in a habitat. Discuss how organisms depend on each for Investigate the symbiotic relationship between plants and fungi (Mycorrhiza and lichens). Teachit Science resource
community. A stable community is one where all the species and environmental factors are in balance so that population sizes remain fairly constant. 4.4.2.3 Abiotic factors that can affect a community are: light intensity temperature moisture levels soil pH and mineral content wind intensity and direction carbon dioxide levels for plants oxygen levels for aquatic animals. Biotic factors that can affect a community are: availability of food new predators arriving new diseases one species another. Name biotic factors in a habitat and explain how a change in a biotic factor might affect a community, eg: availability of food new predators arriving new disease organisms one species another so the numbers are no longer sufficient to Name abiotic factors in a habitat and explain how a change in an abiotic factor might affect a community, eg: 1 Discuss factors that may affect the numbers or distribution of plants and animals in a habitat. Use interactive modelling to change an environment and explore the impact of factors on the interdependence of organisms, eg poisons, disease, food shortages etc. WS 1.2 Predict how a change in an abiotic, or biotic, factor would affect a given community given appropriate data or context. MS 2c, 4a Extract and interpret information from charts, graphs and tables. Model changes in an environment. Students plan how they investigate the effect of hedge boundaries on crop yield. What biotic and abiotic factors might affect the crop?
light intensity temperature moisture levels soil pH and mineral content wind intensity and direction carbon dioxide levels for plants oxygen levels for aquatic animals. 4.4.2.4 Ecologists use a range of investigation methods using transects and quadrats to determine the distribution and abundance of species in an ecosystem. Describe how to out a field investigation into the distribution and abundance of organisms in an ecosystem. Explain how to determine numbers in a given area. 1 MS 2b Calculate arithmetic means. MS 4a, 4c Plot and draw appropriate graphs, selecting appropriate scales for the axes. MS 2d Understand the principles of sampling. Required practical 12: measure the population size of a common species in a habitat. Use sampling techniques to investigate the effect of a factor on the distribution of this species. Biology AT 1, 3, 4, and 6 Extend the practical to investigate the effect of an abiotic factor on distribution of species. MS 2b, 2d, 4a, 4c Teachit Science resource
building, quarrying, farming, clearing woods and other activities that destroy habitats the destruction of peat bogs, and other areas of peat, to produce garden compost pollution of streams, rivers and by sewage, toxic wastes and fertilisers. An example of a global impact of human activities is global warming leading to climate change (Links to 4.4.1, The Earth's atmosphere). Explain why peat should not be burnt. Evaluate the use of fertiliser on plant growth and oxygen levels. Describe what herbicides and pesticides are used for. Observe a block of peat and some peat compost. Discuss what peat is used for and why. Demo burning peat. Show images of a peat bog, peat drying and peat being burnt. Explain why the destruction of peat bogs is harmful to the environment. Investigate the growth of plants in ‘peat free’ and peat composts. Discuss the sources and effects of toxic chemicals; what pesticides and herbicides are used for. Demo to investigate the effect of fertiliser on growth of duckweed and oxygen levels. Monitor results over next few lessons. WS 1.4 Evaluate given information about ways in which human reduce carbon dioxide emissions Using prior understanding, students synthesise the importance of Mycorrhiza with the use of fungicides in agriculture and gardening. Ask students to plan an experiment to measure the water retention properties of peat and peat-free composts. Discuss appropriate graph to show results Composts: ‘peat free’ compost peat-based compost plant pots seedlings. Demo: beakers containing different concentrations of fertiliser duckweed plants oxygen sensors data loggers.
activities affect the environment. 4.4.2.7 There are programmes to reduce these negative effects on ecosystems and biodiversity. These include: breeding programmes for endangered species protecting and regenerating habitats reintroducing wider field margins and hedgerows in areas of monoculture recycling resources rather than dumping waste in landfill production of peat-free composts reducing deforestation and carbon dioxide emissions. Describe programmes introduced to maintain biodiversity: breeding programmes for endangered species protection and regeneration of rare habitats, eg coral reefs, mangroves, heathland reintroduction of field margins and hedgerows in agricultural areas reduction of deforestation and carbon dioxide emissions by some governments recycling resources rather than 1 what biodiversity is. Students report on the reintroduction and breeding programmes for spoon-billed sandpipers and/or Madagascan pochard. How do these interventions help local communities? Research the list of programmes that could help to maintain biodiversity. Think-pair-share what individuals, businesses and governments could do to slow down the reduction in biodiversity. Which near-extinct species would you save and why? Discuss why it is difficult to make changes that will maintain biodiversity. WS 1.4 Search images of 'wildlife corridors'. Is there any evidence that such corridors enhance biodiversity? Students draw what they would expect to see in a graph showing changes to woodland as a percentage of land area in UK from 1000 AD – 2015. Then research and discover if their predictions were correct. Many scientists are beginning to discuss 'bio-abundance' How is this different from biodiversity? Is it as important as biodiversity? Find out about the work of the Marine stewardship council. Could/should this model ejfoundation.org/
dumping waste in landfill. Explain and evaluate conflicting pressures on maintaining biodiversity. Evaluate information about methods that can be used to tackle problems caused by human impacts on the environment. be extended to other natural resources? 4.4.3 Inheritance Spec ref. Summary of the specification content Learning outcomes What most candidates should be able to do Suggested timing (hours) Opportunities to develop Scientific Communication skills Opportunities to apply practical and enquiry skills Self/peer assessment Opportunities and resources Reference to past questions that indicate success 4.4.3.1 Sexual reproduction involves the joining (fusion) of male and female gametes (sperm and egg cells in animals). In sexual reproduction there is mixing of genetic information, which leads to variety in the offspring. The formation of gametes involves meiosis. Explain why sexual reproduction produces variation in the offspring, but asexual reproduction does not. Describe sexual reproduction in animals. 1 Recap of reproduction through group work to discuss and share answers to questions: Do we really need males? Is sex necessary? Can scientists solve the world food shortage? Extract DNA from fruits such as onions or kiwi fruit. Observe the long strands which are the polymer Ethical issues:
If the two alleles present are the same the person is homozygous for that trait, but if the alleles are different they are heterozygous. homozygous and heterozygous. Complete a Punnett square to show the outcomes of genetic crosses. Interpret the results of a genetic diagram and use direct proportion and simple ratios to express the outcomes. Describe the genotypes and phenotypes of the offspring. make predictions on simple probability. WS 1.2 Interpret the results of a genetic cross diagram, for a single gene, and understand family trees. MS 1c Use direct proportion and simple ratios to express the outcome of a genetic cross. 4.4.3.4 All the genes present in an individual organism interact with the environment in which the organism grows and develops its observable appearance and character. These characteristics are its phenotype. The variation in the characteristics of individuals of the same kind may be due to differences in: Define the term phenotype. Give examples of characteristics controlled by multiple genes. 1 WS 1.2 Explain why studies involving identical twins help to separate the contribution of genes and the environment to the development of their phenotypes. WS 1.1 a context and related information, discuss the potential importance for medicine of our increasing Use head size and height data for infants, children, adults as an opportunity to discuss the merits of using of ratio and proportion in science. Demonstrate the function and use of height percentile graphs. Students use the information to explain to an audience, eg parents
Spec ref. Summary of the specification content Learning outcomes What most candidates should be able to do Suggested timing (hours) Opportunities to develop Scientific Communication skills Opportunities to apply practical and enquiry skills Self/peer assessment Opportunities and resources Reference to past questions that indicate success 4.4.4.1 Mutations are changes in DNA molecules that may affect Mutation of a gene can alter the proteins that it contains the code for, or even prevent the protein being produced in cells. Mutations can happen when DNA is copied during cell division or when are affected by environmental factors such as ionising radiation. Many mutations have no effect, but some can lead to significant variation. Define the term mutation. Describe how mutations can be caused. Explain that some mutations have no effect, but some can lead to significant variation. 1 4.4.4.2 The theory of evolution by natural selection explains the evolution of all species of living things from simple life forms that first developed more than three billion years ago. If two populations of one species become isolated geographically or environmentally they may evolve in different ways to Describe Darwin’s theory of evolution by natural selection. Describe the main stages of natural selection. 1 Look at exhibition to show the wide variety of organisms that live, or have lived, on Earth. Discuss how they were all formed. BBC activity about Evolution. Watch BBC video clip illustrating survival of the fittest (see resources). Students design an activity to demonstrate the evolution of camouflage using coloured sweets/markers against different coloured backgrounds. The activity can be extended to collect data. Graph the data and use in Video clip Horse ancestor: Darwin and evidence for evolution; extinction:
suit different conditions. If they become so different that they can no longer interbreed to produce fertile offspring they have formed two new species. Watch video clip about ancestor of horses from BBC Walking with Beasts. Draw a flow diagram to explain natural selection. Natural selection role play activities. Peppered moth game; explain in terms of natural selection. Look at pictures of Darwin’s finches and match up with the Galapagos Island they lived on based on food available there. Discuss how you could show that a donkey and a horse are different species. Interpret evolutionary trees. WS 1.2 Use the model in an explanation, or match features of a model to the data from experiments or observations that the model describes or explains. comparisons with other group results Natural selection – beak shapes investigation. Discussion questions: Why do giraffes have long necks? Why would it be unfair to ignore Alfred Russel Wallace when discussing Darwin's theory of evolution by natural selection? What is meant by a 'scientific theory'? Are humans evolving? Do breeds of dog provide evidence for evolution? Is evolution caused by the environment? How does natural selection affect Peer assessment of camouflage activity. Can valid comparisons be drawn? Teachit Science resource
variation within species? 4.4.4.3 Evidence for evolution comes from the study of fossils that show how much or how little different organisms have changed as life developed on Earth. Evolution of bacteria can be observed happening in a much shorter time because they reproduce so fast. Bacteria that cause disease evolve by natural selection when exposed to antibiotics; this gives rise to a resistant strain. Describe the evidence for the theory of evolution by natural selection. Define the term ‘fossil’. Explain what we should do to slow down the rate of development of resistant strains of bacteria. Describe the impact of antibiotic resistance 1 Discuss the evidence we have to support Darwin’s theory and present in a suitable format. Observe fossils or pictures of fossils eg images of a range of trilobites. What factors may have caused the changes visible in the form of the fossils? How much do these observations contribute to the theory of evolution? Discuss how fossils provide evidence for evolution. Students design a presentation for primary schools to show why it is important not to use antibiotics routinely and how they can prevent the spread of infection. Explain how bacteria can become resistant to antibiotics. Explain how antibiotic resistance has impacted on Students produce tables of results from graphs which show antibiotic resistance in bacteria and the impact of antibiotic restriction on resistance. Why did Fleming, Forey and Chain share the 1945 Nobel Prize for Medicine? Use data from antibiotic timeline to plot a graph of year of introduction vs year resistance developed. Calculate the average time between introduction and resistance developing. Students research Teixobactin and provide recommendations to Timeline of the discovery of antibiotics CDDEP interactive antibiotic timeline
4.4.4.4 In studies of evolution it is essential to be able to identify and classify living things. Traditionally living things have been classified into groups depending on their structure and characteristics. Organisms are named by the binomial system of genus and species. As evidence of internal structures became more developed due to improvements in microscopes and progress with the understanding of biochemical processes, new models of classification have been proposed. Modern classifications systems are based on theories about evolution developed from analysis of differences in DNA molecules. Classify organisms based on their similarities. Describe classification using: Kingdom Phylum Class Order Family Genus Species. Explain the importance of the binomial system to name organisms. Explain how modern technologies have affected how organisms are classified today. 1 Discuss classifying; anything from cars to cosmetics. Why do we do it? Do we only classify physical objects? Exhibition of organisms to classify, use post-it notes to explain groupings – observe and discuss choices made by other groups. Watch BBC video clips about Linnaeus and classification (see resources). Compare the classification of related and unrelated organisms using the Linnaeus system. Match images of animals to binomial names e.g. Giraffa camelopardalis. Look at the variety of given to the same plant and discuss why the binomial system is more useful. Exhibition of organisms to classify into groups (this could be the first lesson on evolution). Compare classification information on related and unrelated organisms. Pictures and names of different plants to discuss. Why is disagreement about the total number of Kingdoms? Students research figures for the total number of species. What is the range? Why is there uncertainty about a total for the number of species? Why are Euglena, slow worms, echidna difficult to classify? Exhibition of pictures and specimens of plants and animals. Video clips
Watch BBC video clip about chemical analysis and its use in classifying organisms (see resources). WS 1.1 Show how new methods of investigation and new discoveries led to new scientific ideas How are species and biodiversity connected? Students show similarities and differences between whales and sharks, snakes and in diagrammatic form. 4.4.4.5 Selective breeding (artificial selection) is the process by which humans breed plants and animals for particular genetic traits. Selective breeding involves choosing parents from a mixed population with the desired characteristic. They are bred together. From the offspring those with the desired characteristic are bred together. This continues over many generations until all the offspring show the desired characteristic. Explain why humans selectively breed plants and animals. Describe selective breeding as a type of sexual reproduction. Describe the process of selective breeding and give examples. Explain the benefits and risks of selective breeding in plants and animals. 1 Images of different dogs. Students ‘breed’ and name a new dog from selecting any two – draw a picture of their new breed. Draw a flow diagram to explain the involved in selective breeding. Give examples of characteristics that are selectively bred in plants and animals. Discuss the advantages and risks of selective breeding in plants and animals. Produce a model to describe selective breeding. What was special about the race horse Frankel? Why is artificial insemination not used in the horse racing industry? Consider the social, economic and ethical implications of selective breeding. clips:
The trait can be chosen for usefulness or appearance. Selective breeding can lead to 'inbreeding' where some breeds are particularly prone to disease or inherited defects. Debate: Should people be allowed to dogs? WS 1.3, 1.4 Evaluate the benefits and of selective breeding given appropriate information and consider related ethical issues. 4.4.4.6 In genetic engineering, selected genes from one organism are transferred to another organism which may, or may not, belong to the same species. This process for genetic modification uses enzymes and vectors (such as bacterial plasmids or viruses) to transfer genes. It is much faster than selective breeding. Genes can be transferred to the cells of animals, plants or microorganisms at an early stage in their development so that they develop with the desired characteristics. Crops that have had their genes modified in this way Define the term genetic engineering. Describe the process of genetic engineering and its advantages. (HT only): Describe in detail the process of genetic engineering. Evaluate the use of genetic engineering in medicine, eg in gene therapy and production of hormones and some vaccines. Interpret information about genetic engineering techniques. 1 Think-pair-share what the terms genetic engineering, genetic modification and gene therapy mean. List examples of genetic engineering. Produce a leaflet for a doctor’s surgery to explain how human insulin is produced by bacteria and discuss the advantages of this over porcine insulin. Interpret information about genetic engineering techniques. Research advantages and disadvantages of GM crops. What characteristics may be modified? Produce a web page Use a model to describe genetic engineering techniques. Evaluate the use of genetic engineering in agriculture and medicine. What is 'synthetic biology' and should it be regulated? Provide examples of GM. Students decide criteria and give each example a weighting according to potential risk and benefit. Can a quantitative value be Information on genetically modified food can be found at