SAMPLE PAGES FROM UNIT C. Heinemann Science Scheme Teacher Resource Pack 3 ISBN: UNCORRECTED PROOFS

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1 SAMPLE PAGES FROM UNIT Heinemann Science Scheme Teacher Resource Pack 3 ISBN: UNORRETED PROOFS This sample contains most of Unit from Heinemann Science Scheme Teacher Resource Pack 3 in a PDF format. Because this advance material has not yet been through all checking stages, it may still contain minor errors. The following pages are not included in this sample material but will be in the Pack: test-yourself answers; keywords lists and glossary lists. B. Dawson, 2002, The Heinemann Science Scheme This material may be freely copied for institutional use prior to the publication of the book from which it is taken. However, this material is copyright and under no circumstances may copies be offered for sale.

2 1 Book spread 1 How do plants grow? Learning objectives (from QA Scheme of Work) Pupils should learn: that green plants do not absorb `food' from the soil that green plants use carbon dioxide and water to produce biomass the meaning of the terms `photosynthesis' and `biomass' to represent photosynthesis by a word equation that light is needed for photosynthesis that the raw materials for photosynthesis are taken from the environment around the plant to interpret and draw conclusions from data to decide how to measure the rate of photosynthesis to control variables to present results in tables and graphs, identifying anomalous results Teaching activities 1a ore: How do plants grow? 1b ore: Measuring the rate of photosynthesis Learning outcomes (from QA Scheme of Work) Pupils: identify the source of raw materials in photosynthesis explain the terms `photosynthesis' and `biomass' provide some evidence that plants do not obtain biomass from the soil construct the word equation for photosynthesis identify that the carbon dioxide level is lower in daylight explain this, eg the leaves are using carbon dioxide during the day conclude that photosynthesis takes place when there is daylight devise a way of measuring photosynthesis, eg by timing the collection of a fixed volume of oxygen; by using an oxygen probe describe how the rate of production of oxygen varies with light intensity produce appropriate graphs of their results and identify and explain any anomalous results Homework resources 1 How do plants grow? Specials (learning support) 1 How do plants grow? Extension resources 1 Proving that plants need carbon dioxide for photosynthesis Unit Plants and photosynthesis Scheme of Work

3 2 Book spread 2 What is the role of the leaf in photosynthesis? 3 What happens to glucose produced in the leaves? Learning objectives (from QA Scheme of Work) Pupils should learn: to test for the presence of starch in a leaf to heat flammable liquid safely that chlorophyll and light are necessary for photosynthesis that oxygen is produced during photosynthesis about variation between leaves that leaves are adapted to photosynthesise efficiently how leaf cells close to the upper surface are adapted for photosynthesis that plants store starch that new materials made from glucose produced during photosynthesis lead to an increase in biomass that the glucose from photosynthesis provides energy for all living processes in the green plant to identify what information is needed and use different texts as sources Teaching activities 2 ore: Testing stencilled and variegated leaves for starch 2 Help: Testing stencilled and variegated leaves for starch 3 ore: What happens to glucose produced in the leaves? 3 Help: What happens to glucose produced in the leaves? Learning outcomes (from QA Scheme of Work) Pupils: detect the presence of starch in a photosynthesising leaf and relate it to the presence of chlorophyll relate photosynthesis to the exposure of the leaf to light, eg etiolation explain that oxygen released from photosynthesis is used by animals in respiration describe differences between leaf cells, and explain that those close to the upper surface photosynthesise effectively, eg are long and thin, have many chloroplasts identify photosynthesis as the source of biomass in plants explain that glucose made in photosynthesis is used for respiration describe all parts of the plant as deriving from the products of photosynthesis select, compare and synthesise information from different texts Homework resources 2 What is the role of the leaf in photosynthesis? 3 What happens to glucose produced in the leaves? Specials (learning support) 2 What is the role of the leaf in photosynthesis? 3 What happens to glucose produced in the leaves? Extension resources 2 What do plants do with glucose? Unit Plants and photosynthesis Scheme of Work

4 Book spread 4 What is the role of the root in photosynthesis? Learning objectives (from QA Scheme of Work) Pupils should learn: that roots are adapted to take in water and this is used in photosynthesis that plants use water in many ways that roots require oxygen for respiration to make careful observations and record these in drawings that plants need sources of nitrogen and other elements in the form of minerals that mineral deficiency hinders plant growth Teaching activities 4a ore: What is the role of the root in photosynthesis? 4b ore: Where does the water go next? Learning outcomes (from QA Scheme of Work) Pupils: explain the functions of water in plants, eg in photosynthesis, to transport minerals, to make the plant firm, for cell growth, to cool leaves, to form fruits describe how roots are adapted for taking in water, eg by being spread out, being branched, having a large surface area, having root hairs describe how the root hair cell is adapted for its function explain that root cells need oxygen supplies in the soil for respiration suggest how substances from the soil enter and move through the plant recognise that plants need mineral salts for growth relate a plant's need for nitrates to making protein and hence healthy growth Homework resources 4 Are green plants important? (Note:this homework is preparation for Activity 5) Specials (learning support) 4 What is the role of the root in photosynthesis? Extension resources Unit Plants and photosynthesis 3 5 Why are green plants important in the environment? that photosynthesis removes carbon dioxide from the air and produces oxygen to consider the issues of environmental protection from several perspectives to compare the word equations for respiration and photosynthesis 5 ore: Are green plants important? 5 Help: Are green plants important? describe how carbon dioxide and oxygen concentrations in the air have varied over time explain how photosynthesis and respiration can help maintain the balance of gases in the air identify the main sources of oxygen from photosynthesis identify the advantages and disadvantages of forest conservation for a range of people and other living things 5 Why are green plants important in the environment? 5 Why are green plants important in the environment? Scheme of Work

5 Teacher and technician notes How do plants grow? 1a Resources available ore sheet D-ROM Links with How do plants grow? All resources customisable Book 3 SoW Sc1 1 9 page 1 2f, g, k±n Safety Do not allow students to use the oven. Activity procedure ore 1 Students weigh a dry broad bean seed before soaking it in warm water for 40 minutes. 2 They allow the seed to germinate in water and leave it to grow until it has produced at least four large leaves that have turned dark green. 3 They take the growing plant from the beaker and weigh it. They are asked to explain where the extra mass has come from. Extension There is an optional extension section at the foot of the core sheet, which can be cut off if not required. The plant is heated by the teacher in an oven at to drive off all the water. Students then reweigh it and can see that it is still heavier than the mass of the seed. They are asked to draw a conclusion. Running the activity While the bean is soaking, the class could discuss ideas about how the rate of photosynthesis might be measured. These ideas can be used to introduce Activity 1b. It is most important that the plant is not weighed until it has developed at least four dark green leaves. The dry mass will initially fall as the seed uses its food reserves for respiration. It is only after the seedling starts photosynthesising that the dry mass increases. Materials required For core (per group) broad bean seed digital balance small beaker of warm water from the tap or kettle sheet of blotting paper scissors 250 cm 3 beaker water Additional for extension (per class) access to oven Notes on materials preparation It will take a couple of weeks for the broad bean plant to grow sufficiently. The activity can be structured so that it is revisited later in the unit. Alternatively, with at least two weeks' advance planning, plants can be prepared from weighed seeds prior to the lesson. Sample results ore The mass of the fresh plant will be greater than that of the dry seed. More able students will say that the increase in mass is due to the uptake of water. Extension Although there is a weight reduction after drying, the mass of the plant is still greater than that of the original seed. More able students will realise that the additional mass has come mainly from the air (carbon dioxide). Answers 1, 2 Students may come up with a variety of answers but should be led to the conclusion that the mass increase cannot be due to the water (that has been dried off) so something must have been absorbed from the air. This can then lead on to a discussion of the role of carbon dioxide in the air. 1

6 Teacher and technician notes Measuring the rate of photosynthesis 1b Resources available ore sheet D-ROM Links with Measuring the rate of photosynthesis All resources customisable Book 3 SoW Sc1 1 9 page 1 2f, h±k, m Safety Warn students not to splash the hot lamp with water as this could cause the glass to implode. Mercury vapour lamps give off small amounts of ultraviolet light. Warn students not to look directly at the lamp. Use a shielded lamp if available. Warn students that lamps get hot when in use. Low voltage electricity supplies for lamps must be used. Make sure there are no wet hands or water near the power supply and plug. Activity procedure ore 1 The students are provided with the following apparatus. It is set up with about 30 cm between the weed and the bulb. Elodea 0.1 % sodium hydrogencarbonate solution 2 They measure the distance between the lamp and the pondweed and record the number of bubbles of oxygen liberated in 1 minute. The number of bubbles is proportional to the rate of photosynthesis. 3 They repeat the procedure at different distances between the lamp and pondweed. 4 They use the results to plot a graph. Extension There is an optional extension section at the foot of the core sheet, which can be cut off if not required. Students take readings from their graphs and consider the relationship between the distance (light level) and the rate of photosynthesis. Running the activity To introduce this activity, refer back to the discussion about methods of measuring the rate of photosynthesis in Activity 1a. Mercury vapour lamps are expensive and it may not be possible to have more than one setup. In this case students can take turns to count, and the teacher will need to decide when to increase the distance between the lamp and pondweed. Some students could start their initial recording immediately and draw their full table of results later. Materials required For core (per group) 1dm 3 beaker filter funnel boiling tube 250 W mercury vapour lamp with shield pondweed (Elodea) 500 cm 3 of sodium hydrogencarbonate solution, 0.1% watch or stopwatch metre ruler Notes on materials preparation This practical is quite tricky, but the following procedure should ensure good results. 1 Place the pondweed in a 0.1% solution of sodium hydrogencarbonate rather than water to ensure that sufficient carbon dioxide is available for photosynthesis. 2 Bubble air through the solution using a standard aquarium pump for at least 30 ontinued 2

7 Teacher and technician notes Measuring the rate of photosynthesis continued 1b minutes. This is to ensure that the solution is saturated with oxygen so that the oxygen bubbles produced do not immediately dissolve in the solution. 3 A suitable lamp with shield can be obtained from Philip Harris Education. Sample results ore It is almost impossible to isolate all the variables for this experiment, particularly the state of the Elodea. This means that results will vary. However, the number of oxygen bubbles will decrease as the lamp is moved further away, showing that light is required for photosynthesis. Students should also realise that the number of bubbles indicates the rate at which photosynthesis is proceeding. Extension More able students may be able to determine that a pattern exists whereby the rate of photosynthesis reduces by a quarter each time the distance between the lamp and the pondweed is doubled (the inverse square law). Answers 1 As the distance increases, the number of bubbles decreases. 2 As the light intensity falls, the rate of photosynthesis falls. 3 Inverse square law 3

8 Teacher and technician notes Testing stencilled and variegated leaves for starch 2 Resources available ore sheet Help sheet D-ROM Links with Testing stencilled and variegated leaves for starch Testing stencilled and variegated leaves for starch All resources customisable Book 3 SoW Sc1 2 9 page 2 2f, k±m Safety Eye protection must be worn. Warn students to take care with the hot water. On no occasion should alcohol come close to a naked flame. Ensure that all Bunsen burners are extinguished before providing students with alcohol. Warn students that iodine will stain their skin and clothing. Activity procedure ore and help 1 Some groups of students test a variegated leaf for starch, and other groups test a normal green leaf to which a stencil has been attached. Make sure students know which experiment their group is doing. 2 They find out that chlorophyll and light are required by the plant in order to photosynthesise. The help sheet gives a flow chart to help students visualise the process, and alternative structured questions. This sheet can be given out in addition to the core sheet to students who need it. Running the activity Tell students that they need to make accurate drawings of the leaves. Students need to boil the leaf until it is soft (about 1 minute). They also need to leave it in the alcohol until it is completely decolorised (up to 5 minutes). Materials required For core and help (per group) Bunsen burner tripod, gauze and heatproof mat 250 cm 3 beaker half full of water white paper and pencil for diagrams plant leaf, variegated or with a stencil forceps boiling tube half full of alcohol access to water bath at 90 8 white tile iodine in potassium iodide solution with dropper Notes on materials preparation Geranium plants are ideal as both normal and variegated varieties are available. Setting up the experiment in advance is crucial to its success. The leaves (variegated or with stencil) need to be left attached to the plant in a dark place for 24 hours, to de-starch. Then leave the plants for a further 24 hours in a brightly lit area. Photoflood lamps are ideal for this purpose. If the plants are left in the dark and then used first thing the following morning, the experiment will not work. Sample results Variegated leaves will turn black in areas that were previously green, and brown in all other (previously white) areas. Stencilled leaves will turn black where light had access to the leaf, and brown in all other areas. Answers ore 1 The patterns match. 2 Green 3 hlorophyll is needed for photosynthesis. 4 The shapes match. 5 No, only the parts that received light turned black. 6 Light is needed for photosynthesis. Help 1 same, green, black, green 2 same, not covered, black, light 4

9 Teacher and technician notes What happens to glucose produced in the leaves? 3 Resources available ore sheet Help sheet D-ROM Links with What happens to glucose produced in the leaves? What happens to glucose produced in the leaves? All resources customisable Book 3 SoW Sc1 3 9 page 3 2bij Safety Warn students not to taste any of the substances. Activity procedure ore and help 1 Students examine a range of plant materials. They may also research other plant materials from a library or the internet. 2 They produce a poster showing the diversity of materials produced by plants. Running the activity ore Students look at the materials provided and then research others. Some students could be asked to make a presentation to the class based on their posters. Help As an alternative to the core sheet, the help sheet provides a structured poster for less able students. Materials required For help (per group) vegetable cooking oil piece of wood brown sugar potato tuber lavender oil grains of rice cotton fiber fibre or fabric (white) Additional for core (per group) starch powder corrugated cardboard piece of Quorn access to library or computer connected to the internet (optional) Notes on materials preparation The materials can be stored in containers so that they can be re-used on subsequent occasions. Answers Help Vegetable cooking oil comes from sunflower or suitable alternative plants. Piece of wood comes from any suitable tree. Brown sugar comes from sugar cane. Potato tuber comes from a potato plant. Lavender oil comes from a lavender plant. Grains of rice come from rice plants. otton fibre comes from a cotton plant. 5

10 Teacher and technician notes What is the role of the root in photosynthesis? 4a Resources available ore sheet D-ROM Links with What is the role of the root in photosynthesis? All resources customisable Book 3 SoW Sc1 4 9 page 4 2fkmo Activity procedure 1 Students examine the structure of mung bean roots and try to determine how they are adapted to absorb water. 2 They draw a diagram and label it. Running the activity Mung bean seedlings need to be grown in advance. Students need to treat the seedling with care to avoid damaging it. This is especially true when removing the root system from the vermiculite and rinsing it under running water. Notes on materials preparation Mung beans germinate very quickly depending on the environmental conditions. It is important for technicians to trial this experiment beforehand to determine the time it takes to produce seedlings with the correct amount of growth. Seedlings are needed that have a good root structure with root hairs, and this will take several days. Vermiculite has been chosen as the growth medium as it is much easier for the students to remove this from the growing roots than when compost is used. Sample results The students should notice that the roots are branching (so can find water in different areas) and have many fine root hairs (which increase the surface area for the absorption of water). Answers 1 They are very fine and have a large surface area to absorb lots of water. Materials required Per group Petri dish or small beaker containing mung bean seedlings growing in vermiculite access to running water white tile hand lens 6

11 Teacher and technician notes Where does the water go next? 4b Resources available ore sheet D-ROM Links with Where does the water go next? All resources customisable Book 3 SoW Sc1 4 9 page 4 2fhklm Safety Instruct students in the safe use of a sharp scalpel or knife. Scalpel guards can be made from a short piece of rubber tubing. If knives are used they should be craft knives and fitted with a guard. Activity procedure 1 Students examine the leaves of celery that has been standing in red ink. They should notice that the veins of the leaves have been stained red by the ink. 2 They remove a section from the petiole (although technically inaccurate, this is referred to as the stem). They observe that the ink has been transported through specific areas of the stem, rather than the whole stem. This leads on to the idea that plants have a transport system. Running the activity The celery needs to be stood in ink in advance. Tell students that they need to make accurate drawings of the sectioned stem, and that they need to take care when cutting the section. Materials required Per group stick of celery standing in 250 cm 3 beaker half full of red ink white tile sharp scalpel or knife with guard hand lens Notes on materials preparation The celery sticks should be fresh and placed into the beakers of red ink 24 hours prior to the experiment. It is important that the leaves remain intact. Sample results The veins in the leaves turn red, indicating the passage of the ink. The section will show staining only in the areas called xylem, which is the tissue responsible for the transport of water up the stem. areas stained red Answers 1 The stem is stained red only in small specific areas. This must be where the water is transported up the stem. 7

12 Teacher and technician notes Are green plants important? 5 Resources available ore sheet Help sheet D-ROM Links with Are green plants important? Are green plants important? All resources customisable Spreadsheet for results for graphing Spreadsheet with data ready provided Book 3 SoW Sc1 5 9 page 4 1a, 2bdno Activity procedure ore 1 Homework 4 provides preparation for this activity. Students will have considered some of the arguments for and against destroying the rainforest. 2 Divide the class into two groups, red and green. Each group identifies two speakers and a secretary to take notes. 3 Supplementary information may be handed out to each group (see help below). 4 Allow the groups 15±20 minutes to prepare their cases. 5 Standard debate format should be followed, as described on the core sheet. 6 A vote should then be taken. Help Additional information is provided for students who need it. The help sheet could be used with all groups in the class if preferred. Running the activity It is essential that the homework sheet 4 has been given out during the previous lesson. Materials required Per group sets of envelopes containing the additional information for red and green groups Sample results The verdict may vary and will depend upon the debate that preceded it. 8

13 How do plants grow? Activity 1a ore Aim To understand that plants do not grow by absorbing soil from their surroundings. Equipment broad bean seed digital balance small beaker of warm water sheet of blotting paper scissors 250 cm 3 beaker water access to oven What to do 1 Weigh a dry broad bean seed on a digital balance. Record the mass. 2 Soak the broad bean seed in warm water in a small beaker for 40 minutes. 3 ut the blotting paper so that it is the same height as the beaker. Roll it up and place it inside the beaker. 4 Pour about 2 cm depth of water into the beaker. 5 Take out the soaked bean and place it so that it rests between the beaker and the blotting paper, about 2 cm above the surface of the water. 6 Leave the broad bean to grow for about two weeks. You will need to make sure there is always some water in the bottom of the beaker. Alternatively, your teacher may give you a broad bean that has already been growing like this. 7 When the bean has grown and produced green leaves, carefully remove the bean from the beaker and weigh it again. blotting paper broad bean water Question 1 ompare the new mass with the original mass and discuss this with your group. Where you think the increase in mass came from? Extension 8 Your teacher will place the plant in an oven and heat it until all of the water has been driven off. 9 Reweigh the plant again and compare this new mass with the previous two masses. Question 2 What conclusion can you draw from this experiment? 1

14 Measuring the rate of photosynthesis Activity 1b ore Aim To measure the rate of photosynthesis by counting the number of oxygen bubbles released from pondweed. Equipment Your teacher will give you the apparatus set up as in the diagram. The pondweed should be photosynthesising and giving off tiny bubbles of oxygen. You will also need: watch or stopclock metre ruler The lamp will get very hot. Do not splash water on to the lamp or stare directly at it. What to do 1 Draw a table like the one below ready to record your results. 2 Place the lamp 30 cm away from the pondweed, and write this distance in your table. 3 ount the oxygen bubbles given off in one minute. Take three readings like this and record the results. 4 alculate the average number of bubbles given off in one minute. 5 Move the lamp a further 20 cm away from the pondweed. Record the distance from the pondweed and repeat steps 3 and 4. 6 ontinue moving the lamp away from the pondweed in steps of 20 cm. Each time record the distance and repeat steps 3 and 4. Stop the experiment when the lamp is 1.5 m away from the pondweed. 7 Draw a graph of your results to show the effect of the distance between the lamp and pondweed on the number of oxygen bubbles produced. Results Distance from light to pondweed (cm) Number of bubbles of oxygen per minute Reading 1 Reading 2 Reading 3 Average number of bubbles per minute Questions 1 What do you notice about the effect of distance on the number of bubbles of oxygen produced? 2 If the light intensity decreases as you move the lamp further away, what conclusion can you draw about the need for light by the process of photosynthesis? Extension 8 Use your graph to determine the number of bubbles of oxygen given off at the following distances of the light source: a 20 cm b 40 cm c 80 cm. 3 What pattern do you notice in your results? 2

15 Testing stencilled and variegated leaves for starch Activity 2 ore Aim To find the conditions required for a leaf to photosynthesise. Equipment Bunsen burner tripod and gauze heatproof mat 250 cm 3 beaker half full of water plant leaf, variegated or with a stencil attached forceps boiling tube half full of alcohol access to water bath white tile iodine solution with dropper Wear eye protection. Take care with hot water. What to do 1 Put a beaker about half full of water on a tripod and gauze. Heat it with a Bunsen burner till it is boiling. 2 Your teacher will provide you with a leaf. Half the class will have a variegated leaf (this is a leaf of more than one colour). The other half will have a leaf with a stencil attached. If your leaf has a stencil attached, do not remove it. variegated leaf green leaf paper clip 3 L black stencil While the water is heating, make a clear pencil drawing of your leaf. Show the outline of the different colours if it is variegated, or the position and shape of the stencil. You are now going to test the leaf for starch. Starch will be present in the leaf where photosynthesis has taken place First remove the stencil if there is one. Then use forceps to place the leaf into the beaker of boiling water and leave it there for about 2 minutes. This will break down the cell walls and make the leaf go floppy. Switch off the Bunsen burner and carefully remove the leaf with the forceps. The water and steam will still be very hot, so take care. Place the crumpled leaf into a boiling tube half full of alcohol. Put the boiling tube into the water bath. Leave it until the leaf turns white. Take care again as the water will be very hot. The hot alcohol will dissolve the green chlorophyll out of the leaf. The leaf will turn white. Alcohol is very flammable. Do not have it anywhere near a Bunsen burner flame. ontinued 3

16 Testing stencilled and variegated leaves for starch continued Activity 2 ore 8 arefully remove the leaf with your forceps and briefly dip it into the hot water in the beaker to rinse it. The leaf will go soft. Place the leaf on your white tile. arefully spread it out and add several drops of iodine solution. Leave the leaf for a couple of minutes and then make a clear pencil drawing of what you can see. ompare this with your original drawing. 9 Iodine solution will stain your hands and clothing. 10 Questions for variegated leaves 1 What do you notice about the pattern that was on the leaf and the areas of the leaf that have stained black? 2 What was the original colour of the part of the leaf that stained black? 3 The black stain shows the places where the leaf made starch by photosynthesis. What does this experiment tell you about the role of the green pigment called chlorophyll? Questions for stencilled leaves 4 What do you notice about the shape of the stencil and the areas of the leaf that have stained black? 5 The stencil prevented light getting to some parts of the leaf. Did any of these covered parts stain black? 6 The black stain shows the places where the leaf made starch by photosynthesis. What does this tell you about the role of light in photosynthesis? 4

17 Testing stencilled and variegated leaves for starch Activity 2 Help Aim To find the conditions required for a leaf to photosynthesise. Equipment Bunsen burner tripod and gauze heatproof mat 250 cm 3 beaker half full of water plant leaf, variegated or with a stencil attached forceps boiling tube half full of alcohol access to water bath white tile iodine solution with dropper What to do Use this help sheet after you have carefully read and understood the instructions on the core sheet. The following diagrams will help you carry out your experiment. First, remove the stencil from the leaf if it has one. Wear eye protection. Take care with hot water. Alcohol is very flammable. Do not have it anywhere near a Bunsen burner flame. Iodine solution will stain your hands and clothing. Put leaf in boiling water for 2 minutes to break down cell walls. Put leaf in hot alcohol in a boiling tube placed in a hot water bath until the leaf turns white. Then dip in hot water to rinse. Add iodine solution to leaf. Draw a diagram of the leaf and label what you see. ontinued 5

18 Testing stencilled and variegated leaves for starch continued Activity 2 Help Question for variegated leaves 1 Use the following words to complete the sentences below about the activity that you have just done. You may use each word once, more than once or not at all. black brown dark different green light same The pattern of the leaf and the pattern of the area that stained black were both the. The original colour of the part of the leaf that turned black was.starchturns when iodine solution is added. This shows me that the pigment called chlorophyll is needed for photosynthesis to take place in the leaf. Question for stencilled leaves 2 Use the following words to complete the sentences below about the activity that you have just done. You may use each word once, more than once or not at all. black covered dark different green light not covered same The shape of the stencil and the pattern of the area that stained black were both the. The stencil prevented light getting to some parts of the leaf. The areas of the leaf that turned black were those areas that were by the stencil. Starch turns that when iodine solution is added. This shows me is needed for photosynthesis to take place in the leaf. 6

19 What happens to glucose produced in the leaves? Activity 3 ore Aim To find out what happens to the glucose produced in the leaves by photosynthesis. Equipment vegetable cooking oil piece of wood brown sugar potato tuber lavender oil grains of rice cotton fibre or fabric starch powder corrugated cardboard piece of Quorn Do not taste anything in the lab. What to do Your teacher will show you a range of materials produced by plants. All these materials are made from the glucose produced by photosynthesis. 1 Examine the materials and try to imagine how each one started from simple glucose. 2 Use secondary sources such as the library or the internet to research these and other important plant products. Investigate such things as what plant produces them and what the materials can be used for. 3 Your task now is to produce a large poster to present details of your research, showing the economic importance of plants and plant products. You may wish to consider these ideas: Your poster should be large and colourful. Drawings should be clear and well spaced. Lines and arrows can be used to link things together. Magazines can be used to provide colourful pictures that can be cut and pasted. 4 When your poster is finished, your teacher may ask some of you to use your poster as the basis of a presentation to the class about what you have discovered. 7

20 What happens to glucose produced in the leaves? Activity 3 Help Aim To find out what happens to the glucose produced in the leaves by photosynthesis. Equipment vegetable cooking oil piece of wood brown sugar potato tuber lavender oil grains of rice cotton fibre or fabric Do not taste anything in the lab. What to do 1 Look at the things that your teacher has given you. Each one is made by a plant. 2 In the spaces below, draw a picture of each one. Use colour on your pictures if you wish. There are extra spaces for you to draw in some ideas of your own. 3 When you have completed your drawings, find out which plant each substance comes from. Label your drawings with the names of the plants. Your teacher may allow you to use the internet or text books to help you with your research. 4 Try to think of a good title for your poster. 8

21 What is the role of the root in photosynthesis? Activity 4a ore Aim To understand that a plant's roots are adapted to absorb water. Equipment Petri dish or small beaker containing vermiculite and germinating mung bean seeds access to running water white tile hand lens What to do 1 Your teacher will give you a small dish containing germinating seeds pieces of vermiculite mung beans small dish water arefully remove one of the seedlings and gently shake off any pieces of vermiculite (vermiculite looks like small pieces of polystyrene). You may need to gently rinse the seedling under running water. arefully place the seedling on a white tile and carefully observe the roots using a hand lens. Make a large clear labelled drawing of the roots. Questions 1 What features do you notice about the roots that would make them efficient at absorbing water? 9

22 Where does the water go next? Activity 4b ore Aim To understand that water passes up the stem of a plant. Equipment stick of celery standing in 250 cm 3 beaker half full of red ink white tile sharp scalpel or knife with guard hand lens What to do 1 Your teacher will provide you with a beaker of red ink containing a stick of celery. The celery has been standing in the ink for the last 24 hours. 2 Look carefully at the leaves of the celery. What do you notice? 3 Place the celery on a white tile. Use a sharp knife or scalpel to cut across the celery twice to remove a section approximately 1 cm thick. Take care using a sharp scalpel or knife. Replace the guard between use. cut here 4 Place the cut section on your white tile and make a large clear labelled drawing of what you can see. Your outline should look a bit like this. Questions 1 What conclusions can you make about how the water travels up the stem of the celery? 10

23 Are green plants important? Activity 5 ore Aim To debate the importance of green plants in the environment. What to do Your teacher will put you into one of two groups. Red group: you will be taking the role of cattle farmers bordering the tropical rainforest in South America. You need to cut and burn the rainforest in order to grow grass for your cattle. Green group: you will be taking the role of scientists who are monitoring the effects on the environment of destroying the rainforests. 1 As a group, discuss the results of your homework and make a list of as many ideas to support your case as possible. 2 You will need a secretary to take notes and two speakers to speak on behalf of your group. As a group, choose these three people. 3 Your teacher may give you a sealed envelope with some extra information. You may choose to use it or ignore it when you make your case. 4 Spend 15±20 minutes preparing your case. Remember that you have two speakers so you will need to share out some of the ideas. The debate 5 Your teacher will ask for the first speaker from each group to come out and present their case. The secretary should take notes about what the other group is saying. Your secondspeakerwillthenbeabletospeakaboutthese points and answer them when it is their turn to speak. 6 After each group has had their turn, you will be given a five-minute break to consider the other group's arguments. 7 The second speaker will then speak from each group to sum up all the main points. The jury 8 When all the speaking has finished, you are free to change your mind based on what you have heard from each of the groups. Your teacher will ask for a show of hands to see whether you agree that the rainforests should be destroyed to support the local cattle farmers. 11

24 Are green plants important? Activity 5 Help Aim To debate the importance of green plants in the environment. To provide additional information for students. The sheet should be cut up and the parts given only to the relevant group.... Red group There is not much work available in your village. A local cattle farmer is cutting down rainforest and burning it. He then allows the grass to grow on the fertile ground and puts his cattle to feed on the grass. You are poor and need the money to feed your family. The farmer offers you a job that you desperately need. Without the job your family will starve. You also know that rich western countries are burning millions of tonnes of oil each year that release carbon dioxide into the atmosphere. You are angry that they expect you to starve to save the environment, while they are destroying the environment so they can maintain their luxurious lifestyle.... Green group Weather patterns around the world are changing. There are more storms and sea levels are rising due to global warming. The latest data shows yet another rise in atmospheric carbon dioxide levels. You know that the rainforests are needed to absorb some of this carbon dioxide. Some small islands in the South Pacific will drown in the near future, with possible loss of life, as the sea levels rise. 12

25 How do plants grow? Homework 1 1 Read the passage below and then answer the questions that follow. Where do plants get their food? Two thousand years ago, a Greek philosopher called Aristotle thought plants grew by absorbing all their food from the soil. If this idea was correct, a plant in a flower pot would eventually use up all the soil and fall over. learly this idea of Aristotle's cannot be correct. The problem was that Aristotle did not know about the gases in air. Today we know that the air contains carbon dioxide, but it is still difficult for us to imagine that a wooden table we are working on was made by a plant, out of carbon dioxide from the air and water from the soil. a Explain what was wrong with Aristotle's ideas concerning plant growth. b Suggest why Aristotle could not arrive at the correct answer. c Explain where plants do get the material that they need to grow. 2 opy and complete the following word equation to show what happens when plants photosynthesise. carbon dioxide 1 water 1 3 In order for plants to photosynthesise, they need energy. Explain where plants get this energy from. 4 What happens to the process of photosynthesis at night? Explain your answer. 1

26 What is the role of the leaf in photosynthesis? Homework 2 1 opy the boxes below. Draw a line to link each process in an experiment with the correct reason why it is carried out. Process carried out the leaf is boiled in alcohol a stencil is placed on a leaf the leaf is boiled in water iodine solution is added to the leaf Reason for process to show whether light is required for photosynthesis to show whether starch is present to remove chlorophyll to break down the cell walls 2 Look at the following diagrams of cells found in a normal leaf. opy each diagram and then choose the correct label to write underneath to describe what the cell does. yy yy palisade cell spongy cell epidermal cell This cell has a large surface area and is surrounded by air spaces. This cell covers the upper and lower surfaces of the leaf. Packed with chloroplasts, this cell is found close to the upper surface, to trap sunlight. 2

27 Homework What happens to glucose produced in the leaves? 3 Plants produce glucose as food for respiration. However, they produce much more glucose than they need. Plants convert this spare glucose into a variety of different forms of biomass, which causes the plant to grow. Use a range of secondary sources such as books and the internet to research some of the biomass substances and materials produced by plants. Try to find some specific examples, as well as general uses. Here are some suggestions to include in your research: various types of food natural dyes drugs used in medicine construction industry clothing animal foods fuel decoration furniture alcoholic drinks.... Homework What happens to glucose produced in the leaves? 3 Plants produce glucose as food for respiration. However, they produce much more glucose than they need. Plants convert this spare glucose into a variety of different forms of biomass, which causes the plant to grow. Use a range of secondary sources such as books and the internet to research some of the biomass substances and materials produced by plants. Try to find some specific examples, as well as general uses. Here are some suggestions to include in your research: various types of food natural dyes drugs used in medicine construction industry clothing animal foods fuel decoration furniture alcoholic drinks. 3

28 Are green plants important? Homework 4 Rather than asking questions on work you have done in class, this homework is to prepare for your next science lesson. You will need two highlighter pens ± red and green. (If you do not have highlighters, underline using felt-tip or ballpoint pens.) Your task is to read the following arguments about whether the rainforest should be cut down. Some people think that it is vital to cut it down to preserve local communities. Other people think that it will do irreversible environmental damage. You should read each argument and mark it with a highlighter pen based on the two different points of view about whether the forest should be destroyed or preserved. Red:mark the argument in red if you think it would be one put forward by a local farmer who needs the land for cattle. Green:mark the argument in green if you think it would be put forward by a scientist who thinks that cutting down the forest will damage the environment. Arguments Green plants put oxygen back into the atmosphere. Local farmers need grassland for their cattle. Burning wood returns carbon dioxide to the atmosphere. Tropical rainforests provide the most diverse habitat on the planet. When farmers cut and burn the rainforest, the nutrients from the ash allow new grass to grow. Green plants remove carbon dioxide from the atmosphere. Destroying the forest will kill many animals. The rainforests are a source of plant material for the production of new medical drugs. An increase in carbon dioxide leads to global warming. The rainforests are a major source of wood production to supply the building industry. attle release methane, which is another gas that causes global warming. You may use the library or internet to research further information on this topic. 4

29 Why are green plants important in the environment? Homework 5 Look at the following examples of ways in which we can conserve our resources and reduce the amount of carbon dioxide that we put into the atmosphere. Suggest the advantages and disadvantages of each one and explain how it would reduce the amount of carbon dioxide being released into the atmosphere. Example 1 Power stations produce electricity by burning fossil fuels such as coal and oil. Power stations can now be built to burn willow wood. Willow is very fast growing and willow trees can be grown and harvested each year. The tree is cut to near ground level, but within a year it has grown again to produce a fresh crop of wood for the power station. Example 2 Timber can be harvested for the building industry from forests that are replanted as soon as the timber is cut down. This means that the forest does not get any smaller, but produces a regular crop of good quality timber. Example 3 Electricity can be produced from alternative sources of energy. For example, giant windmills have been built in areas where it is often windy. These `wind farms' generate electricity without producing any carbon dioxide. Example 4 The construction industry can switch from using wood to using other materials such as plastic and concrete. Example 5 Energy-efficient machinery is now readily available. For example, washing machines can now be purchased that use much less electricity for each washing cycle. ars can be made to travel many more miles per litre of petrol. 5

30 How do plants grow? Specials 1 s t r a c t a s n m i b o l f o c a l m a d a p i y b o v g r n d e x g l u e t h j d b i o c f s i r s n g w p o t q d m d k t h l g i x n z o h l u s s u n l i g h t k q m w r c b c d a f o p t u f j o x g e y i e c r y o o s q h f r z j x b t o n e y s v w e w z t k d q l v p n x y u 1 Fill in the gaps, and circle the missing words in the grid. a Leaves make a sugar called g. b Plants do not grow by absorbing s out of the ground. c Plants absorb c d out of the air, to grow. d Plants get their energy from s. e Plants absorb water through their r. f Photosynthesis is the process that plants use to make their f. 1

31 What is the role of the leaf in photosynthesis? Specials 2 1 A student tested a leaf for starch. The following diagrams show what the student did. Unfortunately they are all mixed up. Find the drawing of the first thing the student did. Then draw arrows to link each thing that the student did in turn. L 2 omplete the passage using these words: alcohol black cell wall iodine light The leaf was boiled in water to break down the. The chlorophyll was removed by placing the leaf in hot. When solution was added, the starch that the leaf had made turned. The part of the leaf covered by the stencil did not contain starch. This proves that the leaf needs for photosynthesis. 2

32 What happens to glucose produced in the leaves? Specials 3 1 The jigsaw shows some of the uses of plants. ut out the shapes and make the jigsaw. When you have made it, you can stick it onto a clean sheet of white paper. 3

33 What is the role of the root in photosynthesis? Specials 4 `Build a root' kit You have been provided with parts of a drawing of a root. ut out the drawings along the dotted lines and use them to build a root system for a plant. Stick the pieces onto a clean sheet of white paper. When you have built the root, cut out the labels and stick those onto the sheet. Draw lines from the labels to the root.... Labels long tap root to anchor the plant and get water from deep in the soil wide shallow roots to get surface water and support the plant branching roots to give a large surface area to absorb water root hairs to give large surface area... ground surface ground surface 4

34 Why are green plants important in the environment? Specials 5 1 Read the following statement about plants and animals. Use the information to answer the following questions. Plants make food such as glucose by the process of photosynthesis. They do this by taking in carbon dioxide from the air and giving out oxygen. This is very useful for animals like us. It provides us with the oxygen that we need to breathe. We in turn breathe out carbon dioxide that we make from respiration. Use the following words to complete the word equations for photosynthesis and respiration. You may use each word more than once. carbon dioxide oxygen Photosynthesis 1 water glucose 1 Respiration 1 glucose 1 water 2 What do you notice about the two word equations for photosynthesis and respiration? 3 Suggest why it is not a good idea for us to continue to chop down all the trees in the world's forests. 5

35 Proving that plants need carbon dioxide for photosynthesis Extension 1 You are going to design an experiment to show that leaves need carbon dioxide to photosynthesise. You are provided with the following theoretical pieces of equipment. two glass jars You are also provided with the following information: Soda lime absorbs carbon dioxide. Leaves produce glucose by photosynthesis. Leaves convert spare glucose into starch. Leaves can be tested to see if they contain starch. Air contains carbon dioxide. 1 Use the equipment shown and the information provided to design an experiment to show that leaves need carbon dioxide for photosynthesis. You should remember to control all the variables and to make your experiment a fair test. 2 Write down instructions for the experiment to tell someone exactly how to carry it out, and draw diagrams showing how the equipment is to be set up. 1

36 What do plants do with glucose? Extension 2 1 Plants make glucose by photosynthesis. The formula for glucose is: 6 H 12 O 6 Plants use glucose as the starting point for making many other substances. They can join two molecules of glucose together to make one molecule of sucrose. The formula for sucrose is: 12 H 22 O 11 Sucrose is the kind of sugar that you put in a cup of tea. The equation below shows how plants make one molecule of sucrose from two molecules of glucose. However, when they do this, they also make something else. 6 H 12 O H 12 O 6 12 H 22 O 11 1? ount the numbers of each kind of atom on both sides of the equation and work out what the missing substance is. hoose from the following: H 4 methane O 2 carbon dioxide H 2 O water H 2 O 2 hydrogen peroxide 2 Once plants have made sucrose, they can join sucrose molecules together to make other substances such as starch. Use the internet or sources from your library to find out about starch. Imagine that you are trying to explain what starch is to someone who has no knowledge of science or biology whatsoever. Make a list of what you think are the five most important points about starch, to help you when you explain to this person. 2