Cambridge PRIMARY
Science
Teacher’s Resource
5
with
CD-ROM
Fiona Baxter and Liz Dilley
CAMBRIDGE PRIMARY Teacher’s Resource
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Science
Fiona Baxter and Liz Dilley
5
University Printing House, Cambridge cb2 8bs, United Kingdom Cambridge University Press is part of the University of Cambridge. It furthers the University’s mission by disseminating knowledge in the pursuit of education, learning and research at the highest international levels of excellence. www.cambridge.org Information on this title: www.cambridge.org/9781107676732 © Cambridge University Press 2014 This publication is in copyright. Subject to statutory exception and to the provisions of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published 2014 Printed in the United Kingdom by Latimer Trend A catalogue record for this publication is available from the British Library isbn 978-1-10767673-2 Paperback Additional resources for this publication at www.cambridge.org/delange
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Cambridge University Press has no responsibility for the persistence or accuracy of URLs for external or third-party internet websites referred to in this publication, and does not guarantee that any content on such websites is, or will remain, accurate or appropriate. Information regarding prices, travel timetables, and other factual information given in this work is correct at the time of first printing but Cambridge University Press does not guarantee the accuracy of such information thereafter.
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notice to teachers References to Activities contained in these resources are provided ‘as is’ and information provided is on the understanding that teachers and technicians shall undertake a thorough and appropriate risk assessment before undertaking any of the Activities listed. Cambridge University Press makes no warranties, representations or claims of any kind concerning the Activities. To the extent permitted by law, Cambridge University Press will not be liable for any loss, injury, claim, liability or damage of any kind resulting from the use of the Activities.
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The photocopy masters in this publication may be photocopied or distributed free of charge for classroom use within the school or institution that purchased the publication. Worksheets and copies of them remain in the copyright of Cambridge University Press, and such copies may not be distributed or used in any way outside the purchasing institution. The publisher is grateful to the experienced teachers Mansoora Shoaib Shah, Lahore Grammar School, 55 Main, Gulberg, Lahore and Lynne Ransford for their careful reviewing of the content.
Contents Introduction 5 Unit 1 Teaching ideas 13 1.1 Seeds 16 1.2 How seeds grow 18 1.3 Investigating germination 20 1.4 What do plants need to grow? 23 1.5 Plants and light 25 Check your progress 29
Unit 3 Teaching ideas 80 3.1 Evaporation 83 3.2 Why evaporation is useful 86 3.3 Investigating evaporation 87 3.4 Evaporation from a solution 90 3.5 Condensation 93 3.6 The water cycle 95 3.7 Boiling 97 3.8 Melting 100 3.9 Who invented the temperature scale? 104 Check your progress 105
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Worksheets
Worksheets 2.1 Draw a bar chart of flower colours 68 2.2 Do a sock walk 70 2.3 Design a wind dispersed seed 72 2.4a Draw and press a flower 74 2.4b Look for patterns and make a prediction about flowers 76 2.6 Which colour flowers do pollinators visit most? 78
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1.1a Observe and draw a fruit and seeds 31 1.1b Find a pattern and make a prediction 33 1.1c How many seeds? 34 1.3 Plan an investigation on germination 36 1.4 Draw a bar chart and picture of plant growth 38 1.5 Analysing results on plant growth 40 Unit 2 Teaching ideas 2.1 Why plants have flowers 2.2 How seeds are spread 2.3 Other ways seeds are spread 2.4 The parts of a flower 2.5 Pollination 2.6 Investigating pollination 2.7 Plant life cycles Check your progress
42 46 48 51 54 57 59 61 63
Resource sheets 2.3 Methods of seed dispersal 2.4 Flower part templates 2.7 Life cycle cards
65 66 67
Worksheets 3.1
Investigating evaporation in other liquids 106 3.3 Draw a line graph of evaporation 108 3.4 Separating salt and sand 110 3.6 Design a fresh water system 112 3.7 How fast does water boil? 114 3.8a Draw a line graph of melting 116 3.8b Investigating melting points 118
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Unit 4 Teaching ideas 4.1 Light travels from a source 4.2 Mirrors 4.3 Seeing behind you 4.4 Which surfaces reflect light the best? 4.5 Light changes direction Check your progress
120 122 124 126 128 130 133
Worksheets
Unit 6 Teaching ideas 6.1 The Sun, the Earth and the Moon 6.2 Does the Sun move? 6.3 The Earth rotates on its axis 6.4 Sunrise and sunset 6.5 The Earth revolves around the Sun 6.6 Exploring the solar system 6.7 Exploring the stars Check your progress
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4.2 Making a periscope 134 4.4a Which surfaces reflect light the best? 135 4.4b Which surfaces reflect light best? 136 4.5a Looking at reflections 137 4.5b Measuring angles and reflections 139
5.4a What affects the size of a shadow? 5.4b Using a line graph to show what affects the size of a shadow 5.5a Investigating shadow lengths 5.5b Making your own sundial
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163 164 165
167 171 173 175 176 178 180 182 183
Resource sheets 6.6a 6.6b 6.6c 6.7
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Unit 5 Teaching ideas 141 5.1 Light travels in straight lines 144 5.2 Which materials let light through? 146 5.3 Silhouettes and shadow puppets 148 5.4 What affects the size of a shadow? 150 5.5 Investigating shadow lengths 152 5.6 Measuring light intensity 154 5.7 How scientists measured and understood light 156 Check your progress 157
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Nicolaus Copernicus 185 Galileo Galilei 186 Edmond Halley 187 Facts about the Hubble Space Telescope 189
Worksheets
Make a model of the Sun, the Earth and the Moon 190 6.2 Track the Sun with a shadow stick 191 6.3 Make a model of the Earth’s rotation 192 Worksheets 6.4a Sunrise and sunset data 193 5.2a Which materials let light 6.4b Sunrise and sunset graph 194 through? 158 6.4c Sunrise and sunset for Doha, 5.2b Which materials let light Qatar 195 through? - Drawing a bar chart 159 6.6 Finding out about 5.2c Which packaging materials let an astronomer 196 light through? 160 5.3 Make shadow puppets with your hands 161
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Introduction The Cambridge Primary Science series series has been developed to match the Cambridge International Examinations Primary Science curriculum framework. It is a fun, flexible and easy to use course that gives both learners and teachers the support they need. In keeping with the aims of the curriculum itself, it encourages learners to be actively engaged with the content, and develop enquiry skills as well as subject knowledge. This Teacher’s Resource for Stage 5 gives extensive support for teaching Stage 5 of the curriculum framework. It frequently references the Learner’s Book, ISBN 978-1-107-66304-6, and Activity Book, 978-1-107-65897-4, for Stage 5, offering guidance on how to get the best out of using those products. There are also many additional teaching ideas for you to choose from.
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The main sections in this Teacher’s Resource are:
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Teaching ideas. These give you a whole range of ideas for how to present the topics in the classroom. This includes ideas for classroom activities, assessment and differentiation, and suggestions for ICT resources. References to the Learner’s Book and Activity Book are provided throughout, including guidance notes on the activities suggested in the Learner’s Book. The Teaching ideas are also available in editable format on the CD-ROM included with this Teacher’s Resource, so that you can include your own notes.
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Worksheets. A large collection of worksheets offers further activity and exercise ideas in addition to those included in the Learner’s Book and Activity Book, while some of the worksheets are intended to support the Learner’s Book activities. The worksheets are also available in editable format on the CD-ROM included with this Teacher’s Resource, so that you can adapt them to your own needs. Answers to questions. Answers to all the questions from the Learner’s Book, the exercises in the Activity Book and the worksheets in this resource are provided. We hope you enjoy using this series. With best wishes, the Cambridge Primary Science team.
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Teaching sequence Throughout the Cambridge Primary Science series, the units are presented in the same order as in the Cambridge International Examinations Primary Science curriculum framework, for easy navigation and to help you ensure that the curriculum is covered. However, this is not necessarily the best sequence in which to teach the material. For example, all the biology topics would be taught in one large block, whereas you may prefer to present a more balanced and varied route through the different areas of science. When planning your teaching sequence, it is advisable to think about how the science topics fit in with the other subjects you teach. Unit 5 requires some knowledge of angles, so you should ensure learners have covered the required content of the Mathematics framework before teaching this unit. You should also consider topics within the science curriculum that are best taught at a particular time of year. For example, Unit 2, The life cycle of flowering plants, is best taught at a time of year when there are likely to be plants in flower. Topics 5.1 and 5.5 both have activities that need sunshine. The best time of year to teach these units will therefore depend on where you are in the world.
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We suggest beginning the year with Unit 1, Investigating plant growth, or Unit 4, The way we see things, because both these units start with content that is known and familiar. We advise teaching Unit 4 before Units 5 and 6. Unit 4 provides conceptual background about light which helps learners understand what light is and how it travels in Unit 5, Shadows and Unit 6, Earth’s movements.
Sequence 1:
Unit 2 The life cycle of flowering plants
Unit 3 Evaporation and condensation
Unit 4 The way we see things
Unit 5 Shadows
Unit 6 Earth’s movements
Unit 5 Shadows environment
Unit 1 Investigating plant growth
Unit 2 The life cycle of flowering plants
Unit 3 Evaporation and condensation
Unit 6 Earth’s movements
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Unit 1 Investigating plant growth
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These are two alternative sequences you might consider, depending on your geographic location. Alternatively, you may develop a different teaching sequence which suits you better. In the suggested sequences the following colour code is used: Biology units are dark grey, Chemistry units light grey and Physics units white.
Sequence 2:
Unit 4 The way we see things
Scientific enquiry Scientific enquiry is about how scientific ideas come about, supported by investigations and evaluating the data and other evidence that are produced through those investigations. The ideas underpin all areas of science. Therefore, the scientific enquiry section of the curriculum framework is not included as a separate teaching unit in the teaching sequences suggested above. Rather, scientific enquiry should be taught in an integrated fashion, alongside teaching of the other content areas.
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Cambridge Primary Science has been written to support this way of working. By allowing learners to carry out the activities in the Learner’s Book you will cover all the scientific enquiry objectives in the curriculum framework. These activities can be supported by further activities suggested in the Teaching ideas and Worksheets in this Teacher’s Resource, and through the exercises focused on planning investigations and evaluating data in the Activity Book. Here, we give a further introduction to the scientific enquiry objectives listed in the Cambridge Primary Science curriculum framework for Stage 5. For each framework statement, some background information is given on the level that learners are expected to achieve at this stage. Also, some specific examples are given of activities suggested in this series that can be used to help learners develop each skill. There is a ‘Reference’ section in the Learner’s Book. This contains skills that should be taught as part of the activities within these resources. This section can be used to support learners when needed.
Ideas and evidence
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Know that scientists have combined evidence with creative thinking to suggest new ideas and explanations for phenomena. Learners find out about scientists involved in discovering phenomena about the measurement of temperature in Unit 3, light in Unit 5 and the solar system and the Universe in Unit 6. They discover how one scientist would come up with an idea which would only be disputed hundreds of years later when another scientist obtained evidence and changed the idea. For example, in Topic 3.9, learners find out about three different scales for measuring temperature proposed by three different scientists. In Topic 5.7, learners find out how ideas changed about rainbows. Learners answer questions about this and do their own research into changing ideas about the speed of light. In Topic 6.6, learners discover how ideas about the solar system have changed completely over the years as new information becomes available. Learners answer questions about this and do their own research into the life and discoveries of an astronomer. In Topic 6.7, learners discover how ideas about the Universe have changed over the years as more powerful telescopes and space equipment became available. Learners answer questions about this and do their own research into the Hubble Space Telescope. When learners have predicted events in an investigation they have to test their predictions by observing or measuring and link this with what they already knew in order to make the prediction. For example, in Exercise 1.3 learners make predictions using data on a bar chart and their previous knowledge. In Activity 3.4b, learners predict what will happen and test their prediction by observation. In Activity 5.2, learners predict the results from everyday knowledge, and then test their prediction by observation.
Plan investigative work Make predictions of what will happen based on scientific knowledge and understanding, and suggest and communicate how to test these. Learners often have a fair idea of what will happen in an investigation before they do it. This is a good opportunity to ask them to predict what will happen, record their predictions and then later, after the investigation, compare their results with their predictions. In Worksheet 1.3, learners make predictions about the results from a planned investigation into seed germination and then suggest how to test their predictions. Learners do this again in Activity 4.4. In Activity 3.1b, learners predict what will happen by using what they already know about evaporation. In the questions following Activity 6.4, learners are asked to predict how the length of day will change in April based on what they have seen in data for previous months.
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Use knowledge and understanding to plan how to carry out a fair test. Learners should be able to design simple fair tests in which they change one factor or variable and keep all the others the same. Learners should be familiar with the concept of fair testing. There are several opportunities across the units for you to reinforce the concept. For example: in Worksheet 1.3, learners plan an investigation on germination using fair testing. In Worksheet 2.3, learners design a wind dispersed seed and think about whether they used fair testing techniques. In Activity 3.3b, learners plan a fair test to see how containers of different shapes and sizes affect evaporation. In Worksheet 3.1, learners plan a fair test to investigate evaporation of water and milk. In Activity 4.4, and again in Activity 5.6, learners are asked to plan and carry out a fair test and later asked to comment on the ways they made their test fair in the questions at the end of the topic.
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Collect sufficient evidence to test an idea. By this stage learners should realise that, in science, we have to collect a lot of evidence to prove something. Obviously there is a limit to the amount of evidence that learners can collect but you should reinforce the importance of collecting evidence and keep asking whether they think they have sufficient evidence to test an idea. For example, in Worksheet 2.1, learners collect flowers to test an idea about flower colour but are then asked if they think they have collected enough evidence to test this idea. In questions relating to Activity 1.5, learners must consider whether they have enough evidence. In Topic 3.3 on evaporation, in both Activities 3.3a and 3.3b learners collect enough evidence to test an idea.
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Identify factors that need to be taken into account in different contexts. In this stage, we introduce the concept of factors in several contexts, beginning in Unit 1, where learners look at the factors necessary for plants to grow. They must then identify which of these factors must be taken into account in the investigations they do, for example, investigating plant growth in Activity 1.5. In Topic 3.3 on evaporation, in both Activities 3.3a and 3.3b, learners identify different factors that lead to different evaporation rates. In Worksheet 3.1, learners consider factors to take into account when they plan an investigation into evaporation of milk and water. In Worksheet 2.3, learners must think of another factor they could have taken into account when they design a wind dispersed seed. In Activity 5.4, learners have to consider a control factor and a variable.
Obtain and present evidence
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Make relevant observations. Learners should obtain evidence by making relevant observations from simple practical investigations, and from research using age-appropriate books, websites or from people. They should be able to do this working in small groups or individually. This will include making visual, auditory or tactile observations and finding information from different sources. Learners may need support and guidance in dealing with evidence, for example in sifting relevant information. The skill of collecting evidence should be developed across the whole stage, but examples could include: Worksheet 1.1b, Observing a diagram of a plant to obtain information. Worksheet 1.5, Analyse results on plant growth (data on table). Exercise 2.6, Find information from a graph. Activity 2.1, Observe a seed. Activity 4.3, See what is on your back. Worksheet 1.5, Draw a graph and picture of plant growth. Activity 4.5, Demonstrate how light travels when it reflects. Activity 5.1b, Observe and make shadows Activity 6.3, Use a model to show day and night. Activity 5.4, Is the size of a shadow affected by changing the position of the object?
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The scientific enquiry objective of making relevant observations is common to many activities found in the Learner’s Book and is not therefore always mentioned in the objectives listed for each topic in the Teacher’s Resource. Measure volume, temperature, time, length and force. Measuring is a quantitative way of collecting evidence. Learners will use simple measuring instruments and methods in Stage 5 to measure length, time, temperature and volume. There is no unit on force in Stage 5, so this skill is not covered here. It was covered at Stage 3 and will be treated again in Stage 6. Learners have the opportunity to measure length in Unit 1, topic 1.5, when they measure the height of plants. In Activities 3.1b, 3.3a and 3.3 b, 3.4, 3.5b, they measure volume and in Activities 3.7b and 3.8 they measure temperature. In Worksheets 3.1, 3.7 and 3.8b, learners measure time and temperature. In Activity 5.5, they measure time and length. Learners also use a light meter (if available) to measure light intensity in Topic 5.6. Discuss the need for repeated observations and measurements. You can explain to learners that sometimes we need to repeat measurements to make sure they are correct. For example, if we use a measuring instrument such as a thermometer incorrectly, the measurements will not be accurate. However, the main reason for repeating measurements is to make sure they are reliable and will apply each time an investigation or test is repeated. Learners discuss the need for more data to reach a conclusion in questions following Activity 4.4, in Activity 5.4 and again in Activity 5.5.
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Present results in drawings, bar charts and tables. At this stage, learners should increasingly be making measurements and presenting numerical or quantitative data in tables, line graphs and bar charts. They should be getting to the stage where they can decide which is the best way to show their results, for example, Activity 1.5. In Worksheet 1.4, learners draw a bar chart using data in a table and in Worksheet 1.5 they draw a line graph using data in a table. Learners have more practice in drawing bar charts and line graphs in Worksheets 2.2 and 2.6. In Unit 3, there are many instances when learners record their results in bar charts or line graphs, for example, Activities 3.3a, 3.7b and 3.8, and Worksheets 3.1, 3.3, 3.8a and 3.8b. In Activity 5.4, learners present their results in line graphs. At this level, learners would be provided with blank tables and charts on which to record their results. A number of worksheets and Activity Book exercises are provided to support the activities in the Learner’s Book in this way. More able learners might be encouraged to construct their own.
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Consider evidence and approach
Decide whether results support predictions. This skill is practised on many occasions throughout the stage. Usually results do support predictions but the occasions in which they don’t lead learners to realise that this is why investigation is such an important part of science. For example, in Activity 1.5, learners predict how plants will grow and then make measurements later to see whether their predictions were correct. In Activity 2.6, learners predict how flowers will be pollinated, then observe the flowers to see whether their predictions were correct. In Worksheets 3.1, 3.4 and 3.8b, learners decide whether the results they get from an investigation support their predictions or not.
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Begin to evaluate repeated results. Learners should, by now, be realising that the more results they get the easier it is to evaluate these results and come up with a conclusion. For example, they do this in Activity 5.4. In Activity 3.7b, learners evaluate the temperatures they measured before, during and after boiling point. Recognise and make predictions from patterns in data and suggest explanations using scientific knowledge and understanding. Having gathered evidence, learners should consider it and identify whether patterns exist and then suggest an explanation for the pattern based on what they have learnt so far. They should consider whether their results would be likely to help them predict what might happen in a new investigation, or in the real world. Identifying trends and patterns is a skill that will help learners to formulate general rules about scientific phenomena, such as the pattern of the length of the shadow and the time of day in Q3 Topic 5.5. More practice in this skill is given in Worksheet 1.1b, where learners find patterns in data on fruits and seeds and make predictions based on these patterns. In Worksheet 2.4b, they look for patterns and make predictions about flowers. In Worksheet 3.3, learners describe the pattern in the data of amounts of water evaporated and suggest explanations based on what they have learnt about evaporation.
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Interpret data and think about whether it is sufficient to draw conclusions. At the end of an investigation, learners must interpret their results or data and reach a conclusion based on their results. If learners work in groups it will be interesting to see how different the results are from different groups – this will be an opportunity for learners to appreciate that one set of data is not always sufficient to draw conclusions. Examples of where learners carry out this enquiry skill are in the questions following Activity 5.4 and in the questions following Activity 6.4. More practice is given in Worksheet 1.3, where learners plan an investigation of germination, and in Worksheet 1.5, where learners make a conclusion based on analysis of plant growth. In Worksheet 2.1, learners consider whether there is enough evidence to come to a conclusion about plant colour.
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The following table gives an overview of which resources are available in the Stage 5 products in this series to support each scientific enquiry objective.
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Framework statement
Learner’s Book
Activity Book
Teacher’s Resource
Know that scientists have combined evidence with creative thinking to suggest new ideas and explanations for phenomena
Activity 6.6
Exercise 5.7
Worksheets 6.6a, 6.7
Use observation and measurement to test predictions and make links
Activities 1.2, 3.1b, 3.4b, 3.7b, 5.2
Exercises 1.3, 3.7
Worksheets 1.3, 2.4, 3.2, 3.4
Make predictions of what will happen based on scientific knowledge and understanding, and suggest and communicate how to test these
Activities 1.2, 1.3, 1.4, 4.4, 3.1b, 3.4b, 5.2, 6.4
Exercises 1.3, 3.7, 5.5, 5.6
Worksheets 1.3, 2.6, 3.1, 3.2, 3.4, 3.6, 3.8b
Use knowledge and understanding to plan how to carry out a fair test
Activities 1.3, 2.3, 2.4, 3.3b, 3.5b, 4.4, 5.2
Collect sufficient evidence to test an idea
Activities 1.3, 3.3a, 3.3b, 5.1a
Identify factors that need to be taken into account in different contexts
Activities 1.4, 2.3, 3.1, 3.2, 3.3a, 3.3b, 3.6, 5.4
Ideas and evidence
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Plan investigative work
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Exercises 3.3, 5.5
Worksheets 1.3, 1.5, 2.3, 3.1
Worksheets 1.3, 1.5, 2.3, 3.1
Exercises 3.3, 5.5
Worksheets 2.1, 2.3, 3.1
Exercises 1.1, 1.2, 1.5, 2.6, 3.3, 6.5
Worksheets 1.1a, 1.1b, 1.3, 1.4, 1.5, 2.1, 2.2, 2.3, 2.4b, 3.1, 3.2, 3.4, 3.8b
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Obtain and present evidence Make relevant observations
Activities 1.1, 1.2, 1.3, 1.5, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 3.1a, 3.1b, 3.2, 3.3a, 3.3b, 3.4a, 3.4b, 3.5a, 3.5b, 3.6, 3.7a, 3.7b, 3.8, 4.1, 4.2, 4.3, 4.4, 4.5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 6.1, 6.2, 6.3, 6.4, 6.7
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Measure volume, temperature, time, length and force
Activities 1.5, 2.3 (length), 3.1b, 3.3a, 3.3b, 3.4, 3.5b (volume), 3.7b, 3.8 (temperature) 5.5 (time), 5.6 (light intensity)
Discuss the need for repeated observations and measurements
Activities 1.3, 2.1, 2.3, 2.4, 3.7b, 3.8, 4.3, 5.4, 5.5, 6.2
Present results in bar charts and line graphs
Activities 1.4, 1.5, 2.1, 2.2, 3.1, 3.3a, 3.7b, 3.8, 4.4, 5.2, 5.4, 6.4
Exercise 6.4 (time)
Worksheets 3.1 (time), 3.2 (time and volume), 3.4 (volume). 3.8b (temperature), 5.5b (length and time), 6.1 (length), 6.2 (length and time) Worksheet 2.3
Exercises 1.3, 1.5, 2.6
Worksheets 1.1c, 1.4, 1.5, 2.1, 2.2, 2.6, 3.1, 3.2, 3.7, 3.8a, 5.2b, 5.4b, 6.4b
Consider evidence and approach Decide whether results support predictions
Activities 1.3, 3.4b, 4.2, 4.4
Begin to evaluate repeated results
Activities 3.7b, 5.4
Recognise and make predictions from patterns in data and suggest explanations using scientific knowledge and understanding
Activities 1.1, 1.3, 1.5, 2.4, 2.5, 2.6, 3.7b, 3.8, 5.5
Exercises 5.4, 6.2, 6.3, 6.4
Worksheets 1.1b, 2.3, 2.4b, 2.6, 3.2, 3.7, 3.8a, 3.8b, 5.2c, 6.4c
Interpret data and think about whether it is sufficient to draw conclusions
Activities 1.3, 2.1, 2.4, 3.3b, 3.7b, 3.8, 4.4, 5.1a, 5.4, 6.4
Activity 1.5
Worksheets 1.3, 1.5. 2.1, 2.4b, 3.1, 3.2, 3.7, 3.8b
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Worksheets 1.3, 2.1, 2.4b, 3.1, 3.4, 3.8b
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Worksheet 3.7
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Unit
Teaching ideas Background knowledge Seeds and germination A seed is the product of sexual reproduction in flowering plants. In dicotyledonous plants, such as beans, the seed consists of a miniature plant (the embryo) and two modified leaves (the cotyledons) which contain the seed’s food reserves. Cotyledons – seed leaves which contain food reserves.
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Testa – hard, dry seed coat that encloses and protects the seed.
Radicle – the first root.
Micropyle – opening through which water enters when the seed starts to germinate. (a) External appearance
Plumule – the first shoot.
(c) Longtitudinal section
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(b) Testa removed
Germination
Germination is the process by which the embryo grows and develops into new plant. The new plant eventually becomes a fully mature plant. The energy and raw materials required for growth come from the food stored in the cotyledon.
seed coat
plumule
cotyledons
radicle
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Unit 1 Teaching ideas Seeds need water and warmth to start germinating. When conditions become suitable for germination, the seed takes in water through the micropyle. The tissues absorb water and swell, and the seed coat becomes soft. The radicle grows first. It pushes through the testa and enters the soil. Next, the plumule pushes upwards through the soil. The embryo grows between the cotyledons, and up through the soil. It leaves the cotyledons below the ground. As the plumule grows, it brings the cotyledons for most plants above ground. Note that in broad beans, the cotyledons stay below the ground. It is easiest to observe and understand seed structure and germination if large seeds, such as peas and beans, are used.
Factors needed for seed germination Some seeds need light for germination, but most seeds germinate in the absence of light. The essential factors for seed germination are: water oxygen temperature.
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Water
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A dormant seed contains 10−15% of its mass as water and is generally dry. A dormant seed is one which is inactive and has not yet germinated. The dormant seed has to absorb water to become active and start germination. Water makes the seed coat soft, which causes it to split. The seed absorbs water and swells. Cell processes are activated and germination starts. Water is also needed to bring in the dissolved oxygen for use by the growing embryo.
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Oxygen
Temperature
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Dormant seeds use very little oxygen. When seeds germinate, they need large quantities of oxygen to allow respiration, and other metabolic processes associated with growth, such as hydrolysis of starch to glucose, to occur. The seeds obtain this oxygen from the air contained in the soil. Seeds sown deeply in soil often fail to germinate because they do not have enough oxygen. Seeds are likely to germinate better in ploughed soil because ploughing aerates the soil (adds air, and therefore oxygen to the soil).
Germination can take place over a wide temperature range (from about 5 –40 °C), but the optimum temperature (best temperature) for most seeds is between 25 –30 °C.
Plant growth Like animals, plants require air, water and food for survival. They also need light. Light is essential for plant growth because it is used in the process of photosynthesis. In photosynthesis, plants make food substances such as glucose and starch. Chlorophyll, the green pigment in plants, absorbs the light in order for photosynthesis to take place. Light is also needed for the formation of chlorophyll. This is why plants kept without light are yellow and not green. Plants require both oxygen and carbon dioxide gas. They use oxygen for the process of respiration. They use carbon dioxide during photosynthesis as a source of carbon for the manufacture of food molecules, for example, starch. Water is needed for photosynthesis. Without water, the stems and leaves of plants would not be strong and firm. Water transports dissolved food, oxygen and minerals around the body of the plant, much as blood does in the human body.
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Teaching ideas Unit 1
Unit overview Topic
Number of lessons
Outline of lesson content
Resources in Learner’s Book
Resources in Activity Book
Resources in Teacher’s Resource
1.1 Seeds
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A seed contains an embryo that grows into a plant.
Activity 1.1
Exercise 1.1
Worksheet 1.1a
Under the right conditions, seeds germinate and grow a first root and first shoot.
Activity 1.2
2 (over a period of one week)
Seeds need water, warmth and air to germinate.
Activity 1.3a
2 Note: Cover an area of grass two or three days before the lesson.
What do plants need to grow?
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1.4 What do plants need to grow?
1.5 Plants and light
Ex
Worksheet 1.1c
Ex
Questions 1, 2, 3, 4, 5 Ex
Exercise 1.2
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Exercise 1.3
Worksheet 1.3
Ex
Activity 1.3b Questions 1, 2, 3, 4, 5
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1.3 Investigating germination
1
Su
Worksheet 1.1b
Activity 1.4
Exercise 1.4
Questions 1, 2, 3, 4, 5, 6
Worksheet 1.4
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1.2 How seeds grow
Questions 1, 2, 3
Su
2 (over a period of three weeks)
Investigating plant growth.
Activity 1.5 Questions 1, 2, 3
Exercise 1.5
Su
Worksheet 1.5
Ex
Challenge activity
Ex
Check your progress
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Cambridge Primary Science 5
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Unit 1 Teaching ideas
Resources
Curriculum links
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You can link this lesson with Art. Learners can make coloured drawings of different fruits and their seeds. They could also make seed pictures from dried beans, lentils and sunflower seeds.
Ideas for the lesson Find out what learners already know by asking them where seeds come from and what seeds do. Learners will know that we plant seeds to grow new plants, but they may not know that seeds are found in fruits.
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Show learners examples of different fruits, including some that they would not instinctively classify as fruits, such as a pumpkin, cucumber or tomato. Explain that seeds form inside fruits.
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Talk about the numbers of seeds and the sizes of seeds that different fruits have. Get learners to think about patterns in these features.
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Get learners to do Worksheet 1.1b, which can be completed at home if there is not enough time in class. Learners have to recognise a pattern in the number and sizes of seeds and make predictions based on this pattern.
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fruits with seeds, such as cucumber, tomato and pumpkin large fresh seeds, such as broad beans a hand lens water a container for soaking seeds in a selection of different seeds a saucer a plant for making cuttings from, such as geranium, impatiens (Busy Lizzie), basil or African violet a knife, scissors or secateurs an onion glass jars soil, sawdust, paper towel or cotton wool a measuring cup or cylinder some small seeds such as mung (moong) beans or lentils small plastic bags and bag ties drinking straws a candle a bell jar or large glass jar a brick two similar pot plants a dark cupboard a ruler
Topic 1.1 Seeds
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Learners will have explored how seeds develop into plants in Stage 1. This topic builds on that knowledge. Learners will discover that seeds develop inside fruits and grow into new plants. Each seed contains an embryo, which develops into the new plant.
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Ask the class why a seed is able to grow into a new plant. Discuss the structure of seeds. It will be helpful if learners can observe real seeds during this discussion.
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Get learners to do Activity 1.1, in which they examine and make observations of seed structure. They should answer Questions 1–3 about the functions of different parts of a seed. Exercise 1.1 in the Activity Book consolidates the learning from this topic. Worksheet 1.1c gives learners an opportunity to practise data handling skills.
Learning objectives
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Know that plants reproduce. Discuss the need for repeated observations and measurements.
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Recognise and make predictions from patterns in data, and suggest explanations using scientific knowledge and understanding.
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Interpret data and think about whether it is enough to draw conclusions. Present results in bar charts and line graphs.
Activity 1.1
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Notes on practical activities Each group will need: a large fresh seed a hand lens.
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Learners should work in groups of 4 or 5.
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Cambridge Primary Science 5
Teaching ideas Unit 1 Large seeds are best. Try broad bean seeds or other large bean seeds. Chick peas are also suitable. Maize seeds are not suitable because they cannot be split in two to see the internal structure. Seeds should be soaked for an hour or two to soften the seed coat and make it easier to peel away. The seed coat should be wrinkled but the seed should not have absorbed much water and swelled yet.
Differentiation
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Demonstrate the use of a hand lens if the learners have not used them before. Some learners may struggle with their drawings of seeds. Support them by giving clear guidelines: Look very carefully at the object you are drawing. Notice the shape and size of the parts, how many parts there are and how they are arranged.
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Press lightly with your pencil in case you make a mistake and have to erase it.
Lower achieving learners can use Worksheet 1.1a to practise their drawing and observation skills. Higher achieving learners could research why some fruits, such as bananas and some varieties of grapes, are seedless. How do the new plants grow? (Note: seedless fruits actually do contain seeds at some point. However, a genetic mistake prevents the seeds from forming hard outer coats like normal seeds do, and the seeds do not develop. Because seeds don’t form, new plants cannot grow from seeds. They come from cuttings instead. For example, a piece of the grape vine is cut off, dipped in rooting hormone and then placed in moist soil so that roots and leaves form. With bananas, new shoots grow from the base of the plant and produce flowers and fruits.)
Talk about it!
Ask the class what they think the answer is. Do big plants produce big seeds? You could ask them to do some research to find out. The largest seed is the Coco de mer, the seed of a palm tree. It can reach about 30 cm long, measure 3 m in diameter and weigh up to 18 kg. The palm tree grows to about 30 m tall. But other trees like redwoods found in the USA grow to about 100 m tall and have much smaller seeds than the Coco de mer seed.
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Make sure your drawing is big enough to see all the parts clearly. You may have to draw them bigger than they really are. Always label the parts of a drawing. Draw pencil lines with a ruler to the parts you want to label. Write the labels with a pen. Write the labels in line with one another down the page. Leave enough space between the label lines so the labels are clear.
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You can extend the activity by letting learners observe different seeds. Ask these questions: Do all seeds look alike inside? Are the food storage areas alike? What and where is the embryo? What does the embryo look like? Where are the future leaves?
Internet and ICT The website: http://www.easyfunschool.com/ article1941.html has ideas for exploring fruits and seeds further.
Assessment
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Can learners label the parts of a seed correctly? Ask learners to check each others labelled drawing of a seed made in Activity 1.1 and suggest any corrections that need to be made. Get learners to look at their diagrams of the seed from Activity 1.1 and the fruit from Worksheet 1.1a. Are they happy with them? How can the diagrams be improved?
Common misunderstandings and misconceptions Many learners at this level think that all fruits are sweet and edible. In this topic, you will be introducing the biological concept of a fruit that will address this misconception. You should also explain that not all fruits are edible and some may be poisonous. Learners should never eat any unknown fruit, no matter how colourful or tasty it looks.
Homework ideas
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Exercise 1.1 in the Activity Book could be completed by lower achieving learners.
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Worksheet 1.1c can be completed by higher achieving learners. The worksheet asks learners to identify a pattern in results, think about using repeated measurements to draw a conclusion and present the results in a bar chart. Cambridge Primary Science 5
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Unit 1 Teaching ideas
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Discuss answers to homework in class. Allow learners to check their own answers for self-assessment.
Answers to Learner’s Book questions 1 So that the embryo can get energy to grow into a new plant. 2 To protect the inside of the seed. 3 Learners may suggest water, warmth, soil, air.
Answers to Activity Book exercise 1 Maria (girl 1) is right. A pumpkin is a fruit because it has seeds. 2 food store seed coat
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Worksheet 1.1b 1 2 3 4 5
The plum has the largest seed. The kiwi fruit has the smallest seeds. The kiwi fruit has the most seeds. The plum has the fewest seeds. Fruits with small seeds have lots of seeds. Fruits with large seeds have few seeds. 6 No. Only four fruits were investigated. To be able to form a conclusion you would have to look at lots of different fruits. 7 The seeds would be quite big.
Worksheet 1.1c 1
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embryo
2 orange 3 The flesh is soft. 4 The flesh is juicy. 5 The seeds are white. 6 a eight seeds b The seeds are small.
Number of seeds
avocado pear
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orange
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broad bean
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3 embryo – grows into new plant seed coat – protects the seed scar – joins the seed to the fruit food store – gives the seed energy to grow
Fruit
groundnut
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Answers to Worksheets
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Learners’ drawings will depend on the fruit they choose. If there are no fruits available, they can draw and label the orange from the Worksheet.
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Number of seeds
Worksheet 1.1a
Drawings must be:
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Neatly drawn with a sharp pencil. Clearly labelled with label lines drawn with a ruler.
skin
flesh
seeds
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At least 5 cm high and 5 cm wide.
Answers and drawing are based on an orange. 1
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Cambridge Primary Science 5
Avocado Orange Broad pear bean Type of fruit
Ground nut
3 a The avocado pear will. The number of seeds will be different in the others. b Cut open lots of each type of fruit and count the seeds.
Topic 1.2 How seeds grow In this topic, learners learn about the stages in the process of germination. Knowing the stages of germination is not required by the
Teaching ideas Unit 1 curriculum, but this addtional material is important for understanding the life cycle of the plant. Learners observe the changes in seeds as the seeds prepare for germination.
Learning objectives
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Investigate how seeds need water for germination.
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Make relevant observations.
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Make predictions based on scientific knowledge. Decide whether results support predictions.
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It will start growing. It will get bigger. It will get softer. It will split open.
The bean seed swells up and becomes softer. This happens because water enters the seed and makes it swell and get softer.
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Learners can then start doing Activity 1.2. At the start of the activity, they must predict the changes they expect to take place in the seed overnight. The activity should be completed the next day. Learners observe the changes that have taken place and decide whether their observations support their predictions.
Learners may give range of answers. The best answer is at the scar. It is the only opening on the outside of the seed coat.
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If possible, show the class a video clip of seed germination so they can see all the stages (see Internet and ICT). Discuss the stages that take place.
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Learners may give a range of predictions at the start of Activity 1.2, which could include:
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Begin the lesson by revising the structure of a seed. Ask the class what happens when the seed starts to grow. What makes the seed start growing? Which part of the seed grows? You can record learners’ ideas on the board in a mind map.
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Learners can prepare their beans and make a prediction about what will happen to the seed in the water at the end of one lesson. They should note their prediction. In the next lesson, let learners observe how their beans have swollen. They can also feel the seed and observe that it quite soft. They should compare their observations to their prediction.
Ideas for the lesson
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Learners should work in groups of 4 or 5.
You can add to the discussion of the ‘Talk about it!’ question by demonstrating how to make a leaf or stem cutting. Learners could make their own cuttings and observe the growth of their cuttings. Most soft-stemmed plants are suitable to make cuttings from. If possible, also show the class examples of bulbs or corms. These are underground stems which develop shoots that grow into new plants. Exercise 1.2 in the Activity Book consolidates the learning from this topic.
Internet and ICT
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The website: http://videos.howstuffworks. com/discovery/30704-assignment-discoverygermination-of-a-seed-video.htm has a good
quality time lapse video on germination.
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The website: http://www.kidsgrowingstrong. org/germination gives a simple explanation for learners about germination. The website: http://urbanext.illinois.edu/ gpe/case3/c3facts3.html has an interactive game and text about seeds and germination featuring Detective Leplant and his partners Bud and Sprout.
Assessment
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Can learners correctly sequence the different stages in the process of germination? Get them to peer assess the answers to Exercise 1.2.
Notes on practical activities
Differentiation
Activity 1.2
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Each group will need: a bean seed a saucer of water.
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Lower achieving learners can be supported if you read through the instructions for Activity 1.2 with the class to ensure that they understand the task. Lower achieving Cambridge Primary Science 5
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Unit 1 Teaching ideas
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learners can also do Exercise 1.2 in the Activity Book, which will help them consolidate their understanding of the different stages in germination. Higher achieving learners could find the information to answer these questions: What is seed dormancy? How can it be ended? Can seeds start growing into new plants while they are inside the fruit?
Talk about it!
Common misunderstandings and misconceptions
Homework ideas
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1 Correct order of pictures is: i Seed coat splits. ii The first root grows. iii The first shoot grows. iv The first leaves grow. v Leaves get bigger and seeds shrivel. 2 Yes. The seed absorbs water and swells.
Topic 1.3 Investigating germination In this topic, learners conduct investigations to determine the conditions needed for seed germination.
Learning objectives
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Questions 1–5 in the Learner’s Book. Discuss answers in class at the start of the next lesson. Allow learners to check their own answers for self-assessment.
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Use knowledge and understanding to plan to carry out a fair test.
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Discuss the need for repeated observations and measurements.
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Make predictions of what will happen based on scientific knowledge.
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Collect sufficient evidence to test an idea. Interpret data and think about whether it is sufficient to draw conclusions.
Ideas for the lesson
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Start the lesson with a discussion about what people and pets need for growth. Explain that plants also have needs for growth. Ask learners for ideas about what seeds need to make them start to grow.
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Use Worksheet 1.3. Discuss the statements made by the learners in the picture on the worksheet. Record your learners’ ideas and suggestions in a mind map.
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In Activity 1.3a, learners make observations and suggest a reason for them based on deduction.
Answers to Learner’s Book questions 1 Seeds need to absorb water to start the growth process/germination. 2 a The first root is the first part to grow. b The first root grows downwards to get water and to anchor the new plant in the ground. 3 The first shoot grows upwards. It needs to break through the soil to get light.
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Investigate how seeds need water, warmth and air for germination but not light.
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A common misunderstanding is that seeds are not living things because they do not actively show any characteristics of living things. Seeds are living. They contain an embryo that is capable of germinating to produce a new plant. Seeds use small amounts of stored energy to stay alive and are ‘waiting’ for good conditions to begin to grow. Most seeds need water and certain temperatures to begin to grow.
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Answers to Activity Book exercise
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Bring an onion to class. Ask learners how they can grow a new onion. Do they need onion seeds? Many of them will have seen an onion sprout roots and shoots. New onions grow from the onion bulb that we eat. You could also make a leaf cutting a few days in advance from a plant such as a begonia. New roots will start to grow from the leaf as the leaf begins to grow into a new plant. Explain that we can grow plants from other parts of the plant, such as stem and leaf cuttings and from bulbs and corns.
4 The new leaves start to grow above the ground because they need light so they can make food for the plant. 5 The seed shrivels and becomes small after germination because the food store gets used up during germination.
Cambridge Primary Science 5
Teaching ideas Unit 1
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Next, start Activity 1.3b. Learners can set up their jars of seeds and draw their observation tables.
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After eight days, learners should answer the questions relating to the activities on page 11 of the Learner’s Book. The questions address learners’ understanding of a fair test and get them thinking about the need for repeated observations and measurements. They also make predictions and use these predictions to plan their work.
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Exercise 1.3 in the Activity Book consolidates the learning from this topic.
Notes on practical activities Activity 1.3a Each group will need: ten small seeds such as mung (moong) beans or lentils paper towel water two small plastic bags two bag ties a drinking straw.
Possible results for Activity 1.3b are given here, but the learners may come up with different numbers of germinated seeds. Days Number of seeds germinated
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Before the lesson, set out the materials so that learners can collect them from a central point. Fill the jars with sand or sawdust in advance. Use seeds that germinate fairly quickly and are large enough to be observed easily. Kidney beans, peas or seeds of similar size are suitable. The seeds will take a few days to germinate. Carry on with the next topic during this time. Demonstrate how to place the seeds against the sides of the jar. The seeds must be visible so that their growth can be observed. You can use paper towel or cotton wool on saucers instead of soil or sawdust in jars. As these materials dry out quickly, learners must keep the relevant seeds moist at all times. You could extend the activity by getting learners to draw bar charts of the results they obtain.
Dry soil in warm place
Moist soil in cold place
Dry soil in cold place
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Learners should work in groups of 4 or 5.
Moist soil in warm place
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Use smaller seeds as they will germinate quickly. Radish and cress seeds germinate very quickly, so you could use them as alternatives if they are available. The plastic bags must be big enough for a saucer to fit into. You could use Petri dishes instead of saucers, if they are available. Demonstrate how to suck the air out the plastic bag with the straw. Learners should hold the bag closed around the straw while they suck out the air. They must quickly pull out the straw and tie the bag without getting any air into it. The results for Activity 1.3a should be as follows. After two days the seeds in the bag containing air germinated. No seeds germinated in the bag without air. The reason is that seeds need air to germinate.
Activity 1.3b Each group will need: twenty seeds four glass jars soil or sawdust water a measuring cup or cylinder.
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Learners should work in groups of 4 or 5.
1 Give jars the same amount of water, use the same number of seeds, use same amount of soil in each jar 2 a More seeds germinated in the jar with moist soil in a warm place. No seeds germinated in the jars without water. The germinating seeds in the jar with moist soil in a warm place grew best. The seeds in moist soil in a cold place did not grow as well. The seeds in the other jars did not grow. b Reasons could include: seeds need water and warmth to germinate and grow. c Using more seeds would give better results because it would show that the growth patterns of the seeds observed under different conditions can be repeated. 3 No. There is air all around us and in soil. None of the seeds had any air. 4 Seeds need water, warmth and air to germinate.
Cambridge Primary Science 5
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Unit 1 Teaching ideas 5 a No – light is not needed for germination. b Use two jars, each with the same number of seeds, in moist soil. Place one jar in the dark, inside a cupboard. Place the other one in the light in the same room, but not in a warmer place. Observe the differences between the seeds in the two jars every two days for eight days.
Worksheet 1.3 Each pair or group will need: big and small seeds glass jars soil water saucers paper towel water.
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Light a candle and place it next to one of the saucers.
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Place a bell jar or large glass jar over each saucer.
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Let learners observe that the candle goes out in the one jar. Explain that this is because the candle uses up the oxygen gas in the air inside the jar. The air in the other jar still contains oxygen gas.
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Leave the jars in a warm place for two days and then observe how many seeds germinated in each jar. Discuss the observations. You could explain that living things need the oxygen in air. Seeds therefore need the oxygen to germinate and grow. When there is no oxygen in the air, seeds cannot germinate.
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Learners should work in pairs or small groups.
The website: http://www.buzzle.com/articles/ steps-of-seed-germination.html gives a good overview of factors and processes involved in germination.
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Internet and ICT
Assessment
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Get learners to plan the investigation. Set out the materials they will need and allow them to choose how to set up the experiment. This can be done in one lesson. To make the test fair, they should give the big and the small seeds the same amount of water and put them in the same place so they get the same amount of warmth and air.
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Learners will need to leave the seeds for about two days before the small seeds start to germinate.
Get learners to check their seeds every day until all seeds have germinated. During this time the seeds must be kept moist. Learners should discover that larger seeds take longer to germinate. Once the seeds have germinated, learners can decide if their prediction was correct or not and form a conclusion.
Differentiation
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Alternative activity or demonstration This is an alternative to show that seeds need air for germination. You can use this demonstration to introduce the idea that oxygen in air is necessary for living organisms to stay alive and grow. Do not allow learners to work with the lighted candle.
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Place seeds on a damp paper towel on two saucers as in Activity 1.3a.
Cambridge Primary Science 5
Can learners identify the conditions (factors) that seeds need for germination? Have a quick question-and-answer session in class to find out. Name each factor, and ask the class to say if it is needed for germination or not. You can include some other factors that have no effect such as day length, type of soil, and how deep the seed is planted.
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Lower achieving learners will benefit if you sit down with them on a one-on-one basis to make sure they understand the lesson. After answering their questions and helping them to get started, check back occasionally to make sure their progress is on track. They can also work in mixed ability groups with more able learners who can provide peer support. Higher achieving learners could do Worksheet 1.3 in which they plan an investigation. This activity addresses learners’ understanding of fair tests, their ability to use existing knowledge to make predictions and collect sufficient evidence.