Life And Living [grade 6 English]

WESTERN CAPE PRIMARY SCIENCE PROGRAMME An example of a learning experience in the Natural Sciences

LIFE

& LIVING

Grade 6 We all depend on plants 1 What do all living things do and need? 2 Plants provide us with food and other things 3 What food do we get from plants? 4 How do plants get their food? 5 Plants make their own food in a process called photosynthesis 6 Testing a green leaf for starch 7 Starchy foods are our staple foods 8 We say thank you for our food 9 Home-cooked food and processed food 10 Eating a balanced diet

© Western Cape Primary Science Programme (PSP)

An example of a learning experience in the Natural Sciences

LIFE

&L

IVING

Grade 6

We welcome the wide use of these materials. Please acknowledge PSP.

©PSP 2006/7

Rationale These materials were written to support teachers in their work with learners around the content area of Life and Living. This is not a complete work schedule. It is an example of a learning experience. It offers possibilities for teachers to include other learning experiences and to extend and develop it further. This example learning experience shows how you can work towards the three Learning Outcomes in the Natural Sciences of the National Curriculum Statements (NCS).

LO1: Scientific Investigations A

The learner will be able to act confidently on curiosity about natural phenomena, and to investigate relationships and solve problems in scientific, technological and environmental contexts

LO2: Constructing Science Knowledge A

The learner will know and be able to interpret and apply scientific, technological and environmental knowledge

LO3: Science, Society and the Environment A

The learner will be able to demonstrate an understanding of the interrelationships between science and technology, society and the environment We know that children are naturally curious and observant. Children learn about the world by observing, asking questions and trying to make sense of what they experience. Science teaching should allow these natural tendencies to keep growing. Encourage your learners to ask questions. Questions are an opportunity to engage the class in observations and discussions.

In Science we want students: A to develop a lively curiosity about the world around them A to be confident to raise questions A to link their questions to what they observe in their home environments and in

the world. This can lead to a rich thinking, talking and writing environment. Children who have this curiosity will learn and become creative human beings too.

Assessment The assessment tasks in this group of learning experiences are directly linked to the Learning Outcomes of the NCS. They are designed to encourage learners to show what they know, to show what they are thinking and to record and show you their questions. Courses presented by Nontsikelelo Mahote, Rose Thomas, Wendy Hitchcock and Nadiema Gamieldien Booklet designed by Welma Odendaal Illustrated by Janet Ranson, Nicci Cairns and Wendy Hitchcock

Western Cape Primary Science Programme (PSP) Edith Stephens Wetland Park Lansdowne Road, Philippi, 7785 P O Box 24158, Lansdowne 7779 South Africa Tel: 021 691-9039 Fax: 021 691-6350 E-mail: [email protected] Website: www.psp.org.za Acknowledgement PetroSA

Contents SECTION 1 We all depend on plants Learning experiences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3–42 Assessment tasks LO2 Understanding the process of photosynthesis . . . . . . . . . . . . . . . . . . . . . . 13 LO1 Investigating staple foods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 LO3 Making better food choices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Suggested workscheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

SECTION 2 Teacher resources Learner task cards to photocopy Task card 1 What do all living things do and need? . . . . . . . . . . . . . . . . . . . . . . . 46 Task card 2 What foods do we get from plants? . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Task card 3 Sustaining our food plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Assessment task for LO2 Understanding the process of photosynthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . Task card 4 Write a recipe for photosynthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . Task card 5 Test a green leaf for starch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Task card 6 Test different foods for starch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

51 53 54 55

Assessment task for LO1 Investigating staple foods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Task card 7 Analysing home-cooked meals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Task card 8 Comparing home-cooked food with processes foods . . . . . . . . . . . 63

Assessment task for LO3 Making better food choices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Task card 9 Reflecting about Life and Living . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information on GM foods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Poem in Isixhosa: UMNGA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Story in Afrikaans: Dirkie mens en snytjie brood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

67 68 69 70

Teaching aids for photosynthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

SECTION 3 Extracts from the National Curriculum Statements for Natural Sciences Grades R – 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Core knowledge and concepts for Life and Living (NCS) . . . . . . . . . . . . . . . . . . . . . 77 – 81 Learning Outcomes and assessment standards (NCS) . . . . . . . . . . . . . . . . . . . . . . . . 82 – 87

SECTION 1 SECTION 1 We all depend on plants 1. What do all living things do and need? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 2. Plants provide us with food and other things . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 3. What food do we get from plants? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 4. How do plants get their food? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 5. Plants make their own food in a process called photosynthesis . . . . . . . . . . . . . . .11

Assessment task for LO2 Understanding the process of photosynthesis 6. Testing a green leaf for starch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 7. Starchy foods are our staple foods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Assessment task for LO1 Investigating staple foods 8. We say thank you for our food . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 9. Home-cooked food and processed food . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 10. Eating a balanced diet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

Assessment task for LO3 Making better food choices Readings: Luxury foods and diseases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 The Secrets of African Women . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

Suggested workscheme

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What do all living things do and need? Teacher task

Key concepts M

M

M

There are seven life processes: movement, reproduction, sensitivity, growth, respiration, excretion, nutrition. All living organisms carry out these seven life processes. To carry out our life processes we need food, water and air.

Introduction

1. Ask: What do all living things do? Encourage all answers, but lead learners to link their examples to the seven life processes. LIFE PROCESS

Common examples that learners might give

Movement

Moving towards light, food or water; walking; running; swimming; flying

Reproduction

Having babies; laying eggs; making seeds

Sensitivity

Seeing, feeling, sensing pain, tasting, hearing, smelling

Growth

Getting bigger; growing

Respiration

Breathing; using air

Excretion

Urinating, sweating

Nutrition

Eating, drinking, chewing, swallowing

2. Explain that all living things carry out these seven life processes to stay alive. Ask: What do living things need to carry out these processes? Use the picture below in your discussion. 3. An easy way to remember the life processes is to use the first letter of each process (MRS GREN). 4. Draw a picture of a child on the board and write the seven processes around the picture. Learners say what they need in order to carry out each process.

What does my body need to carry out its life processes?

Movement

NUTRITION Food for GROWTH and REPRODUCTION

Reproduction Sensitivity Growth Respiration Excretion Nutrition

Water for my cells and blood

SENSITIVITY so I can feel

Energy for MOVEMENT Oxygen for RESPIRATION

Water for EXCRETION (sweat and urine)

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see learner task card from page 46 to copy.

Learner Task Card 1

What do all living things do and need? Look at the picture ‘My body needs ...’ Make sure you know what each life process is. Write sentences to explain what your body needs to carry out each process.

MOVEMENT

My body needs to eat and digest food to give me energy. I use the energy to move. My body needs space to move around in. My body also needs exercise to strengthen my bones and muscles. If my bones and muscles are strong, I can move. RESPIRATION

My body needs to breathe clean air that contains oxygen. SENSITIVITY

I use my sense organs to smell, taste, touch, see and hear things in the world around me. My senses help me to smell and taste my food. I use my sense of touch to avoid pain and to know when I have hurt myself. GROWTH

My body needs healthy food including proteins, starches and fresh fruit and vegetables to grow properly. REPRODUCTION

My body will need healthy food to grow and develop properly so that one day I can find a partner and have children. EXCRETION

My body needs to have plenty of water so that my kidneys can make urine (ukuchama) and my skin can sweat. NUTRITION

My body needs to eat and digest food to get energy. My body needs healthy food and a balanced diet to grow and stay healthy.

Consolidation Learners act out the seven life processes in their groups.

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2 Key concepts M

M

Plants provide animals with food to eat and oxygen to breathe. We get many products from plants.

Plants provide us with food and other things Teacher task 1. Discuss why plants are so important in our lives. Provide headings from the mind map below. 2. Ask what we need plants for. Each learner writes one idea on a piece of paper. 3. Collect the pieces of paper and use them to construct a large mind map. 4. Ask the class to arrange their ideas under the different headings. The diagram gives you some subheadings you can use for your mind map. These are suggestions only. Use your own or learners’ ideas too, and add new ideas at any time.

5. Learners can copy the mind map into their books.

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3 Key concepts M M

M

M

M

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All animals depend on plants for food. Some animals eat other animals that have eaten plants for their food. People get some food from plants and some from animals. People rely on food that comes from just a few important plants. Some foods are called staple foods. Staple foods are the foods that give us most of our energy to live. Rice, maize and wheat are important staple foods.

What food do we get from plants? Teacher task 1. Learners write down what foods they eat. 2. Use the table to record the foods they eat and find out what plant each food comes from. See learner task card 2 to photocopy on page 48

Learner Task Card 2

What foods do we get from plants? What foods do you eat regularly? What plants do these foods come from? Fried chips, mashed potato

Potatoes

Bread

Wheat plant (also rye plant)

Salad

Tomato plant, cucumber plant, lettuce plant, onion plant

White sugar, syrup, sweets

Sugar cane

Cabbage

Cabbage plant

Lentils, beans or chick peas

Bean plants

Chocolate

Cocoa plant

Oil

Sunflower plant, canola plant, olive tree

Tea

Tea bush

Spinach

Spinach plant

Onion

Onion plant

3. Read the information that follows or assist learners to read it to each other. Explain what the word ‘sustain’ means.

Learner Task Card 3

Sustaining our food plants Food for our bodies To stay healthy, we need to eat a balanced diet. A balanced diet contains foods from the main groups. The main food groups are: carbohydrates, proteins, minerals and vitamins, fats and oils, and fibre. M Carbohydrates give us energy. We get them from starchy foods such as bread, rice and potatoes. M Proteins help our bones to grow. We get them from foods like meat, eggs, milk, beans and nuts. M Minerals and vitamins are found in fruits and vegetables. They help us to fight diseases. M Fats and oils help our skin and hair to stay healthy. We get them from butter, margarine, oil and nuts. M Fibre helps our digestion. Fibre is the hard, chewy part of plants such as apples, pumpkin and wheat. Staple foods All around the world the main food that people eat is called their staple food. Staple foods provide people with the main carbohydrate (starchy) part of their diet for each day. Staple foods give us energy. Some of the important staple foods around the world are rice, maize and wheat. In most places, people eat the staple foods that grow most easily in their areas. In South Africa, our staple foods are maize, wheat and potatoes. In West Africa, cassava and yam are staple foods. In Asia, rice is a popular staple food. Sorghum, oats and sweet potatoes are also staple foods in some areas of the world where they grow. People who live in cities can eat a variety of staple foods from around the world, which they can buy in shops. Grass feeds the world! Almost all the staple foods come from plants that belong to the grass family. Maize, wheat, rice, oats, rye, barley and sorghum all come from kinds of grasses. The sugar cane plant is also a grass. We also get our meat and milk indirectly from grasses because cows, goats and sheep all feed on grass. Traditional foods Traditional foods come from local crops. Farmers collect the seeds from their crops each year to plant the next season's crops. This helps them to sustain the crop (keep it going year after year). Some traditional foods grow wild and seed themselves, for example, wild spinach (umfino), marula fruit, prickly pears, msoba-soba berries, sour figs (suurvye) and blackberries all grow wild. Traditional foods can provide us with important minerals and nutrients. Foods in shops are not as fresh. When they get packed and transported, they lose a lot of their minerals and nutrients. Improving the harvest Farmers often try to increase the amount of food that they can harvest from their crops. They add manure or fertilisers to the soil to provide their crops with mineral salts. They also use chemicals to control pests and diseases, which can attack their crops. We all depend on farmers to sustain our food plants around the world.

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4. Learners answer the following questions about the readings. a) What is a ‘staple food’?

It is the food that forms the main part of our diet. b) What important food group is found in all staple foods? What do we need it for?

Carbohydrates (or starch) is found in all staple foods. We need starch for energy. c) What family of plants provide most of the world’s staple foods?

Staple foods come from plants belonging mainly to the grass family, for example, maize, wheat and rice. d) What do we mean by a traditional food?

Traditional food usually grows close to where people live. e) What do farmers do to increase the amount of food from their crops?

They add fertilisers and compost to the soil and they spray the plants with poisons to kill any diseases. f) Name some traditional foods that grow wild. Say which ones you have eaten.

Traditional foods that grow wild: marula fruit, blackberries, umfino. (Learners’ answers will vary.)

Consolidation Facilitate a class discussion about the following questions: M The world’s population depends on just a few types pf plants for almost all our food. Is this a problem or not? M Why must we look after and sustain our traditional food plants? M Would we be able to survive without plants? M Who should look after our food plants and their seeds? Should it be big companies? Should it be the governments of the world? Should it be farmers? Should it be scientists? Why? Make sure learners understand that we cannot live without the plants that provide us with food.

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How do plants get their food?

4 Key concepts M M M

Plants need energy to grow. Plants do not get energy food from the soil. Plants only get water and mineral salts from the soil.

Teacher task 1. Bring a plant in a pot to school for the learners to look at. 2. Explain the following information to the class. We know that animals and humans need food to grow. In the past people thought that plants got their food from the soil. Now we know that plants make their own food. Remember, the food groups are carbohydrates, proteins, fats and oils, and vitamins. Plants cannot get these from the soil. Plants only need mineral salts and water from the soil to help them make their own food.

Van Helmont’s experiment In 1577 a man called Jean-Baptiste van Helmont did an experiment over 5 years in which he grew a small plant into a big plant by feeding it nothing but water. He weighed the plant and the soil at the beginning. After five years he weighed the plant and the soil again. Van Helmont found that the soil weighed the same but the plant had grown in size. Its mass after five years was 76 kg. The soil still had the same mass as at the beginning. Where did the plant get enough food (energy) to grow to that size?

What do plants need to grow? 5 years later only water was added

SMALL PLANT: 90 kg dry soil; plant weighs 2 kg.

PLANT HAS GROWN BIG 90kg dry soil; plant weighs 76kg now

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3. Draw a picture of the plants on the chalkboard like Van Helmont’s experiment. 4. Ask: What must we give the small plant to make it grow into a big plant? Must we give it: M Water? M Sunlight? M More soil? M Fertiliser? M Mineral salts from the soil? M Anything else? M Could you grow if you were only given water and soil to live on? 5. Have a discussion with the class about these questions. M What was van Helmont trying to prove with his experiment?

He was trying to prove that the plant got its food from the soil. Plants grow better if we feed the soil. This soil food is called compost or humus. It releases minerals slowly back into the water of the soil. We can also feed the soil with chemical fertilisers. They are concentrated forms of mineral salts. Plants cannot get their energy from these mineral salts.

M

What did he discover?

He found out that the weight of the soil did not change and therefore that the plants did not ‘eat’ the soil. M

Why were his results a surprise?

People knew that animals eat plants or other animals to get their energy and people assumed that plants used up the soil in the same way. M

Where do you think plants get their food and energy?

Plants make their own food.

Consolidation Learners make a poster showing what a plant needs to grow.

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Plants make their own food in a process called photosynthesis

5 Key concepts M

M

M

M

M

Plants make their own food (starch) in the process called photosynthesis. Photosynthesis takes place inside the cells of green leaves. During photosynthesis the plant uses sunlight energy, carbon dioxide and water to make glucose sugar. Plants also change glucose sugar into starch, which they store in their roots, leaves and stems. During photosynthesis, the plant uses carbon dioxide and gives off oxygen into the atmosphere.

Teacher task

Explaining photosynthesis

1. The diagram and information below summarise the process of photosynthesis. Using this diagram, make a display on the board or wall to explain how plants make their own food through photosynthesis. Explain the process carefully to the class. You will find an explanation on the next pages.

Photosynthesis

Light energy Leaves release Oxygen (O2)

Leaves use Carbon dioxide (CO2) Leaves make glucose and starch

Animals and humans release Carbon dioxide (CO2) water and mineral salts

Animals and humans use Oxygen (O2)

Water and mineral salts

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Photosynthesis Photosynthesis means to build up food using light energy. Photosynthesis comes from the words ‘photo’ meaning light and ‘synthesis’ meaning to make something. Photosynthesis is what plants do to produce food using light energy. Nearly 200 years after van Helmont’s experiment, scientists found out that green plants make their own food. The leaves take water and carbon dioxide gas from the air and use the energy from sunlight to make food in the form of glucose sugar, and starch. We call this process photosynthesis. Photosynthesis is a chemical reaction that takes place in green leaves.

Oxygen (O2) and carbon dioxide (CO2) During photosynthesis, plants give out oxygen gas. All the oxygen in the air comes from photosynthesis. People and animals need oxygen so that we can breathe. We cannot live without plants and photosynthesis. We breathe out carbon dioxide, which is poisonous to us. But plants use it up again during photosynthesis.

Plants are the only organisms that can make their own food Plants are the only organisms that can absorb light energy from the sun and convert it into chemical energy in the form of glucose. Then the glucose can be used by animals.

Summary Photosynthesis is a chemical reaction. We write it like this: Water + carbon dioxide + sunlight energy R glucose sugar + oxygen H2O + CO2 +

sunlight energy R C6H12O6

Plants are the only living things that make their own food. All other living things depend on plants for their food.

+ O2

Green plants take water and sunlight and carbon dioxide, and use them to make food. In the process they put oxygen back into the atmosphere.

So, green plants are the only things that can make food? That’s right. People and animals can’t make glucose and starches. Even factories can’t do this. Without plants we would have no food, no fuel and no oxygen. 12

Learner Task

Learner task card to photocopy on page 51

Assessment Task for LO2

Understanding the process of photosynthesis A. Read and discuss In the sunlight Green plants absorb light energy from the sun. In the roots The roots take up water and mineral salts from the soil into the plant. In the leaves Leaves absorb the gas carbon dioxide. Plants make a food called glucose sugar. Then the plants convert glucose sugar to starch so that they can store it. Leaves release oxygen gas into the air. In the plant Plants store the sunlight energy as food (starch) in their flowers, seeds, fruits, roots, leaves and stems. In the environment Humans and animals eat plants for food. Humans and animals breathe out carbon dioxide gas. Humans and animals breathe in oxygen gas.

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B. Use the drawing below (or make your own) to show the process of photosynthesis. On your drawing make arrows and write labels to show where: M Sunlight energy goes M Water and mineral salts go M Carbon dioxide goes M Oxygen goes M The plant makes glucose sugar and starch

C. Write a few sentences to explain why photosynthesis is important for life on Earth.

Photosynthesis produces starch and glucose for all living things. Photosynthesis uses up carbon dioxide and gives us oxygen to breathe. Plants are the only things that make their own food. All life depends on plants and photosynthesis.

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Suggested guide for assessment of LO2 Understanding the process of photosynthesis Assessment task

Assessment criteria: LO2

Draw a picture of plants and animals (or use the picture given) to show the flow of substances during photosynthesis

The learner must … Make a clear drawing with arrows pointing in the correct direction to show: I Sunlight energy from sun to plants I Water and mineral salts from the soil into the roots of the plant I Carbon dioxide from the animals and humans into the leaf I Oxygen from the leaf to the animals and humans I Starch from plants to humans and animals

Write a few sentences to explain why photosynthesis is important

Show the correct understanding of the following facts: I Only plants can make their own food by photosynthesis. People and animals also depend on that food. I Plants use CO2 from the air, water and mineral salts from the soil and sunlight energy to make glucose sugar and starch. I All animals and humans get oxygen from plants. I Plants use up the poisonous CO2 in the air. I Give exceptionally full, correct and clear explanations of photosynthesis.

To earn a code 4 assessment (80%)

Consolidation 1. Ask learners to write a recipe for photosynthesis.

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Learner task card to photocopy on page 53

Learner Task Card 4

Write a recipe for photosynthesis Pretend you are an old plant telling a young plant how to make starch

A recipe for starch How to make glucose and starch Ingredients What substances do you need to make this food?

Water, carbon dioxide and sunlight. Method What steps must you follow to make the food?

1. Take up water from the soil through your roots. 2. Take carbon dioxide from the air into your leaves. 3. Let the sunlight shine on your leaves. 4. Use water, carbon dioxide and sun energy to make glucose sugars. 5. Join the glucose sugars together to make starch. Questions a) What is left over after the plant has made glucose and starch?

Oxygen b) Where does this leftover substance go and who uses it?

Oxygen goes into the air. Humans and animals use it for breathing. c) Where does the plant make its food?

The plant makes its food in the green leaves.

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6 Key concepts M

M

M

M

Photosynthesis occurs in green leaves when they are exposed to sunlight. During photosynthesis, the leaf makes glucose sugar and then changes it into starch which the plant can store easily. Glucose sugar is soluble (can dissolve) in water but starch is easier to store because it is insoluble (cannot dissolve). We can use iodine solution to test for the presence of starch in plants.

Testing a green leaf for starch Teacher task

Introduction

1. Remind learners that all living things are made of cells and that each leaf is made of millions of cells. 2. Tell learners that photosynthesis occurs inside the cells of green leaves. The leaves trap the light energy from the sun and change it into chemical energy. The chemical energy is stored inside the glucose and starch. Starch and glucose are food substances because they contain chemical energy. 3. Explain that we can test a leaf for starch. If there is starch in the leaves, it shows us that photosynthesis has occurred. Demonstrate the positive starch test on a piece of cut potato. Show how a drop of iodine changes the colour from brown to purple, or blue-black or black when starch is present. 4. Work through the task with the learners. Afterwards, read the poem about food factories with the class.

straw

brown iodine solution

cut potato iodine turning black

Preparation 5. Prepare sets of equipment for groups to do the experiment (as illustrated in Task Card 5). Try the experiment beforehand to find leaves that show a good positive result. You will need: M a small jar (e.g. a jar from baby food) M a styrofoam cup M ethanol or methylated spirits M kettle to boil water M iodine solution with dropper M waxed paper cut into squares (or the lids of plastic ice-cream boxes) Learners will need to pick a leaf from a plant that has been in the sun for a few hours.

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SAFETY PRECAUTION! Do not work with ethanol or methylated spirits near an open flame. It is highly flammable and may explode.

Learner Task Card 5

Test a green leaf for starch Follow the instructions in the diagrams below. Then answer the questions that follow. 1. Put a leaf in a baby food jar. Cover it with boiling water and leave for 2 minutes. Boiling water destroys the membranes of the cells.

1 boiling water

2. Put the leaf in a baby food jar. Cover it with methylated spirits (or ethanol). The methylated spirits removes the green chlorophyll from the 2&3 leaf. After a while, the leaf should be white or pale green and hard.

baby food jar leaf hot water methylated spirits

3. Place the baby food jar in styrofoam cup of boiling water.

styrofoam cup with boiling water

4. Dip the leaf in hot water. Hot water makes the leaf soft again.

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5. Put the leaf on a square piece of waxed lunch wrap (or a plastic lid). Put a drop of iodine solution onto the leaf. The iodine will turn black where starch is present.

5 iodine solution

Learner task card to photocopy on page 54

Consolidation 1. Learners answer these questions. a) Did we find starch in the leaves we tested?

Yes b) How could we tell that there was starch in the leaf?

Because the iodine tested positive. c) What does iodine do when starch is present?

It turns blackish-purple. d) Where do plants make their food?

In their leaves. 18

Food factories Green plants are busy factories That keep us all alive. Without them we would have no meat, No honey from the hive. Though energy from sunlight Supplies our every need, Without green plants to capture it, Where would we be indeed? All day we use up oxygen With every breath we take, Forgetting that without the plants, Our lives would be at stake. So, though we think we’re clever, Our brains amount to nil If we forget our livelihood Depends on chlorophyll. From: Nature Poems and Puzzles, Jill Cadle

Cholorophyll is the chemical that makes leaves green. Photosynthesis only takes place in green leaves.

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Starchy foods are our staple foods

Key concepts M

M M M

M

Plants make starch. Starch is also is called a carbohydrate food. Plants can store starch in different parts of the plant. Some foods contain starch. Iodine changes from brown to dark purple or black when starch is present. The foods that contain the most starch and form the main part of our diet are called staple foods.

Teacher task

Introduction

1. Explain the following information to learners.

Plants make many different substances During photosynthesis, plants make a sugary liquid called glucose. The plant converts glucose to starch (carbohydrate) and stores it in the leaves. Chemical reactions inside the plant’s cells can also change glucose and starch into other substances such as proteins, oils, vitamins and fibres. Plants can also make poisonous substances or chemicals that irritate the skin. Plants do this to prevent animals from eating their leaves. For example, chilli plants make a chemical that makes your skin burn.

Foods usually contain a mixture of food substances All foods from plants contain a mixture of the main food groups - proteins, starch, sugars, oils, vitamins and fibres. All foods contain some of these food groups. Water does not contain any of these food groups so we do not call it a food. Some foods contain one of the food groups in large quantities. For example, beans contain large quantities of proteins. Mealies, on the other hand, contain starch in large quantities. The foods that contain mostly starch (carbohydrate) are called our staple foods. Our staple food usually makes up the biggest part of our diet. We need staple foods because the starch in them gives us energy.

Testing different foods for starch 2. Before the next lesson, ask learners to bring different items of food from home, for example, cooked rice, cereals, porridge, bread, carrots, flour, fruits, and so on. Bring samples of the following foods for your learners to test: M potato M sugar M hard-boiled egg M cooked beans M cheese M flour M cooking oil M maizena

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Note to the teacher You can purchase iodine solution from a pharmacy. When you do the test for starch, put each food sample onto a separate plastic bottle top to prevent those that contain starch from contaminating those that do not. Do not place the food on paper plates, cardboard, roller towel or any other paper products as these all contain starch and will cause the test to show incorrect results.

3. Provide small plastic bottle tops so that each food sample has its own bottle top. You will also need iodine solution in small bottles and cut straws to act as droppers. 4. Explain to the class that some of the foods we eat contain starch. Look at the range of food samples and ask them which foods they think do contain starch. 5. Explain that iodine solution turns from brown to purple, black or blue-black when starch is present. Demonstrate how to test a small sample of food with one drop of iodine on a cut potato. Ask learners to work in groups to test the food samples for starch and to complete Learner Task Card 6.

Learner task card to photocopy on page 56

Learner Task Card 6

Test different foods for starch A. Make predictions. 1. What colour is your iodine solution? ……………………………………………………………… 2. What colour will your iodine turn when you drop it onto a starchy food? ……………………………………………………………………………………………………… 3. List the foods that you think will contain starch: ………………………………………………………………………………………………………

………………………………………………………………………………………………………

………………………………………………………………………………………………………

B. Test different foods. 1. Put a small sample of each food in a plastic bottle top. Make sure that the different foods do not touch each other. 2. Test each food with a drop of iodine. Do not touch the food with the dropper. This could contaminate the other foods. 3. Record your observations in the table.

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Learner Task Card 6 (cont.) Colour when iodine is added

Is starch present?

Food

Plant it comes from

Maizena

seeds of maize plant or mielie black

yes

Sugar

stem of sugar cane plant

brown

no

Cheese

milk from cows that fed on grass

brown

no

Flour

seeds of wheat plants

black

yes

Egg white

chickens that fed on mielies

brown

no

Cooking oil

sunflower seeds

brown

no

Potato

stem of potato plants

black

yes

Cooked beans

seeds of bean plants

black

yes

Bread

seeds of wheat plants

black

yes

Rice

seeds of rice plants

black

yes

Oats porridge

seeds of oat plant

black

yes

Pasta

seeds of wheat plnt

black

yes

Banana

fruit of banana tree

black

yes

Carrot

root of carrot plant

brown

no

Onion

stem of onion plant

brown

no

4. Were your predictions correct?

C. Write your conclusion with your teacher. What I learned from this experiment:

We have found that many foods contain starch. Some foods go very black immediately when iodine is added. Other foods take some time to turn black after the iodine has been added. Cooking oil, egg white, cheese , carrots, onion and sugar do not contain starch.

22

Consolidation Ask and think about 1. Facilitate a class discussion using the following questions: M Were your predictions correct? M Did you all get the same results for the foods you tested? Can you explain why or why not? M Which foods contain starch? M Which foods do not contain starch? M Which of these foods do you think is the most important part of your diet? (They are all important.) The starchy food that provides the biggest part of your diet is called a staple food. 2. Explain that the next part of the investigation is to find out which of our foods are staple foods.

Teacher task Assessment task for LO1

Investigating staple foods A. Discuss questions for investigation 1. What makes a food a staple food?

A staple food is the starchy food that provides the main part of your diet. 2. How did you find out which foods contain starch?

We did a starch test on the foods that we eat to see which ones contain starch. 3. Which foods do you know definitely contain starch?

Bread, rice, potatoes, oats, pasta 4. How would we decide which of these starchy foods are staple foods? In your groups write down some questions to ask your family to find out what staple foods they eat regularly.

What foods do we eat every day? What do you have for breakfast most mornings? What do you usually have for lunch? 5. Discuss which starchy foods you eat most often yourself. These are your staple foods. (Learners’ answers will vary according to their diets.) Learner task card to photocopy on page 56

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Assessment task for LO1 (cont.)

Learner task

B. Conduct investigations, collect and record data. 1. Do this survey. Bring some food you eat often at home to test to see if they are carbohydrates (contain starch). Identify which are the staple foods for your family. Give reasons why you think they are staple foods.

Bread – yes, it tests positive for starch, and we eat it every day. Samp – yes, it tests positive for starch, and we eat it very often. 2. Now that you know which foods are carbohydrate foods (contain starch), carry out a survey about the following carbohydrate foods. 3. Count how many times a day you eat each carbohydrate food. Then complete the table below. Add more lines to the table if you need to add more examples. 4. Work out the total amount for a week and record on the table below.

Jane’s staple foods Staple food

How many times I eat these foods each day

Mon

Tues

Wed

Thu

Fri

Sat

Sun

Total

Potato

–

1

–

–

1

–

–

2

Rice

1

–

1

–

–

1

1

4

Mielie meal

1

1

1

1

1

–

-

5

Bread

1

1

2

1

1

2

2

10

Pasta

–

–

–

1

–

–

–

1

5. Show your findings in a bar graph. Examples for teacher: Graphs to show carbohydrate foods eaten by different people

24

Draw a graph of our group’s results 6. Copy and complete the table below for your group, showing how many times a week each person in your group eats the carbohydrate food. Number of times carbohydrate food (starch food) is eaten each week

Jane

Sipho

Thami

Total

Potato

2

1

2

5

Rice

4

2

6

12

Mielie meal

5

10

7

22

Bread

10

7

4

21

Pasta

1

1

2

4

7. Draw a bar graph for each group using the total number of times your group eats each starchy food.

Graph to show how many times a week our group eats starchy food

25

C. Evaluate and discuss data Discuss these questions in your group and then write answers to them on your own. 1. Explain what we mean by a staple food.

Staple foods are starchy foods, which we eat often. They form a large part of our diet. 2. Look at your graphs. Compare them and decide what is the staple food for each person.

This is the food/s eaten most often in the week. 3. Does every person have the same staple food? Give reasons.

Different people will have different staple foods, for cultural reasons. 4. Compare the staple foods for the learners in your class. What can you say about staple foods in your class?

We all eat staple foods but peoples staple foods are different/are not different. 5. How easy was it to count the number of times you ate staple foods during the week? Do you think your counting was accurate? How could you have improved this survey to make it more accurate? Learners’ answers will vary. Ideas for extension: Find out about a food garden in your area.

Suggested guide for assessment of LO1 Investigating staple foods Assessment task

Assessment criteria: LO1

A. Conduct and record investigations

The learner must … I Bring samples of foods and test them for starch I Record information in their own table I Identify the staple foods they eat I Carry out the survey about these staple foods accurately I Record their counting accurately on a table

B. Collect and record data

I Draw an accurate graph of their results (showing correct

plotting, correct axes, scale, heading and labels) C. Evaluate and interpret data

I Show correct understanding of what we mean by a staple food I Correctly identify staple foods – their own and others’ (the

starchy food that they eat the most of)

Consolidation 1. Discuss the following question with the class: M What do you think is the most important staple food in your family and in your community? M How would you know or find out?

26

8 Key concepts M

M

M

All our food comes from plants or from animals that have fed on plants. All the energy that plants use to make starch comes from the sun. Reverence and gratitude for our food connects us to the Earth and is common to all religions.

We say thank you for our food Teacher task 1. Read the following ‘Thank you’ poem aloud to the class.

Thank you for my slice of bread Thank you for my slice of bread Don’t thank me, thank the shopkeeper where the bread was bought. Thank you shopkeeper for my slice of bread. Don’t thank me, thank the baker who made the bread. Thank you baker for my slice of bread. Don’t thank me, thank the wheat flour that the bread was made from. Thank you wheat flour for my slice of bread. Don’t thank me, thank the wheat seeds from which the flour was made. Thank you wheat seeds for my slice of bread. Don’t thank me, thank the wheat plant that made me. Thank you wheat plant for the bread. Don’t thank me, thank the sun which gave me the energy to grow. Thank you sun for my slice of bread. Don’t thank me, thank God for the bread. Thank you God for my slice of bread.

Learner task

Writing a ‘thank you’ poem Work in pairs. 1. Read the poem. 2. Choose one of your staple foods and help each other to write your own “Thank you” poem for that food. You must start with “Thank you for...” 3. Say your poem to the class. Remember to say it clearly and with respect.

27

9 Key concepts M

M

M

M

M

We need food for energy, to move, to grow and to repair damage to our bodies. We need a balanced diet which contains carbohydrates, proteins, fats, minerals and vitamins. Food can lose its nutritional value during processing. Fresh foods contain higher levels of nutrition than processed foods. We should choose foods that keep our bodies healthy and strong.

Home-cooked food and processed food Teacher task

Explaining about food groups

1. Explain the main food groups to the class. Look at the food group diagram, the background information on staple diets, the table of energy values and the bread label and explain the following concepts: M We can divide food into three main food groups. (See diagrams that follow.) We need to eat a balanced diet, which includes food from each group to keep us healthy. M All foods contain some energy. We measure this energy in kilojoules (kJ). The table that follows shows you some examples of energy values of foods we eat. M The Recommended Daily Allowance (RDA) is the amount of kilojoules that a person needs to eat every day. (See the background information on page 31.) We get this energy by eating different foods. People that are growing and doing hard manual work or a lot of physical exercise need to eat more. M The law says that companies that produce food must print the energy value, ingredients and additives of processed food on the packaging. M Traditionally grown and prepared foods provide people with plenty of fibre, vitamins and minerals. These substances help to keep your body strong and healthy. Traditional foods do not contain extra sugar, salt, fat or chemicals.

Getting the right balance M

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We need to eat balanced meals to stay healthy. To do this, we must try to choose food from all three food groups. There are healthy foods from each group that are not expensive. For example: brown bread (carbohydrate), peanut butter and milk (protein); samp and beans (carbohydrate and protein); mielie meal and amasi (carbohydrate and protein).

The food groups

Group 3: Carbohydrates, fats and oils (Energy foods)

GROUP 1: Proteins (Body-building foods)

GROUP 2: Vitamins and mineral (Foods that protect us from disease)

Why do we need to eat from the three main food groups? Calcium and other minerals to build our bones and teeth Fats and oils are stored under our skin until we need them for energy Vitamins to keep our organs healthy and working well

Starch and other carbohydrates to give us energy for living and muscle movement

Proteins to build and heal our bodies e.g. brains and muscles

Water to provide liquid in our blood

Roughage to help our food move through our intestines

Fibre It is important to eat food that has fibre in it. Fibre helps your food to move properly through your digestive system and prevents constipation. Raw fruits and vegetables, wholewheat flour, brown rice and beans all contain fibre. White flour has had all the fibre removed. Try to reduce the amount of foods that you eat that are made with white flour e.g. white bread, cakes, pastries, and biscuits. Rather eat wholewheat products.

29

Food energy table Food

Amount

Kilojoules (kJ)

Sugar, white

1 teaspoon

64

White bread

1 slice, 40 g

300

Jam

1 table spoon

557

Peanut butter

1 tea spoon

123

Cooked beans

1/2

437

Margarine

1 teaspoon

152

Egg

1 boiled

379

Potato

1 large boiled

293

Potato chips fried in oil

1 small serving

Cola

500 ml

900

Diet cola

500 ml

0

Potato crisps

1 packet 30 g

668

Chicken, fried in oil

1 drumstick

774

Pie, Chicken

1 small pie

2431

Biscuit

1 lemon cream

300

White rice

1/2

cup cooked

435

Maize meal porridge

1/2

cup, stiff (cooked)

463

Chocolate (milk)

1 bar, 100 g

Meat (mutton stew)

1/2

cup

865

Spinach

1/2

cup = 85 g, cooked

82

Pumpkin

100 g boiled

176

Oil

1 teaspoon

184

Samp

1/2

485

Onion

1 cooked

cup = 85 g

cup cooked

955

2241

46

See Learner Task Card to photocopy on page 60. The task card includes the food energy table and diagram of food groups.

30

Recommended Daily Allowance (RDA) In order to live and stay healthy, every person needs to get a basic amount of energy every day. We get that energy every day from our food. This is called the Recommended Daily Allowance (RDA) of food. The energy content of the food is measured in kilojoules (kJ). The RDA for growing girls aged 12 to 15 is 9 000 kJ. For growing boys aged 12 to 15 it is 11 000 kJ. Our staple foods, such as bread, rice or mealie meal, provide us with most of this daily energy. Other foods give us less energy but we need them to build and repair our bodies. We also need a daily allowance of proteins from meat or beans or nuts. We also need minerals such as iron, for building up strong muscles, blood and bones, and to fight diseases.

Teacher task

RDA for boys aged 12–15 is 11 000 kJ

RDA for girls aged 12–15 is 9 000 kJ

A. Foods we eat at home 1. Ask the learners to say what they usually eat for breakfast, lunch and supper. Encourage all anwers. 2. Show the food values table to the learners and make sure they understand that the first column shows the kind of food, the second column gives a quantity and the third column shows the number of kiloJoules contained in that quantity. Ask questions about the table to make sure that they can read values from it, for example: M How many kilojoules in 1 cup of mutton stew? and so on.

B. Foods in the past, present and future 1. Read the following recipe to the learners for a traditional home-cooked meal. Umngqusho onembotyi (Samp and beans) 380 g samp 260 sugar beans 2 litres water 1 large onion, chopped Salt to taste 1. Wash the samp and beans. Cover them with water and soak them overnight. 2. The next morning, drain off the water. 3. Put the water in a large pot and bring to the boil. Add the samp and beans. Make sure there is enough water to cover them. 4. Cook the mixture for 3 hours, adding water when necessary until the ingredients are soft. 5. Add onion and salt and mix well.

31

2. Explain the following to the learners. M Fresh foods prepared at home are usually more nutritious than processed foods. M Traditional and home cooked foods such as fresh vegetables, umngqusho (samp and beans), mealie meal and home-made bread provide more than just the starch for energy. They are rich in proteins and minerals, which are important for growth. Traditional homecooked foods also contain fibre, which is essential for the digestive system. M Processed foods can damage your health. The United States of America is one of the wealthiest countries in the world. But one out of every three Americans is seriously overweight (too fat). This can be very dangerous. M All over the world, people are starting to demand fresh foods that are grown in a natural way. These foods are grown without adding chemicals or insecticides to them. We say they are organically grown. Many people buy organic foods because they want to avoid eating chemicals that can damage their health.

C. Analysing a home-cooked meal 1. Look at the example of a traditional recipe on the previous page and help learners to complete the table. (You will have to refer to the diagram of food groups and the table of energy content of foods on pages 29 – 30)

Learner task card 7

Learner task card to photocopy on page 56

A. Home-cooked food 1. Look at the food energy table and the three food groups. Use the information from the table, and the diagram of the different food groups, to help you fill in the table. Ingredients

Food group/s

Energy

Substances added to the food

Samp

Carbohydrate

485 kJ

Salt

Beans

Proteins

437 kJ

Salt

Onion

Vitamins and minerals

46 kJ

A meal of umngqusho onembotyi (samp and beans)

B. Foods in the past, present and future 1. Find out about foods your parents or grandparents used to make at home. Speak to members of your family or community to find a recipe of a traditional meal in your culture. 2. Write and draw the recipe, using the following headings: name of food or meal, ingredients, method (what to do) 3. Then share the foods and recipe you have written. Include any interesting details about the foods and when and how you eat them.

32

Teacher task 1. Explain the following to the learners.

Processed food Most people do not have the space or time to grow their own food, so they buy their food from a shop. A lot of the food we buy ready-prepared from the shops is processed. Processed means that the raw ingredients have been dried, mixed, cooked or baked already. Processing helps to stop food from going bad. We freeze food, dry it or preserve it with salt, sugar and/or chemicals, and we put it into cans or bottles. In the preserving process, many foods lose their vitamins and minerals. Often the food is ground up and the fibre is removed, for example in making white flour. Sometimes a chemical is added to white flour to bleach it and make it look really white. Sometimes fat and salt, sugar or chemicals are added to food to preserve it or to improve the flavour. Some chemicals added to food are: M sodium benzoate – a chemical added to preserve food M monosodium glutamate – a chemical added for flavour M tartrazine – a yellow or red chemical for colouring the food This means that processed foods are less nutritious than fresh foods. They may also contain chemicals, which may be unhealthy for us.

Fast foods Fast foods such as chips, hamburgers and pizzas are highly processed foods. They are prepared with a lot of white flour, sugar, oil and salt. They are low in fibre. They are high in energy but low in good nutrition. Sometimes we enjoy eating fast foods, but we should only eat them sometimes – not every day!

2. Discuss the following questions with the learners: M What does the term ‘processed food’ mean? M What are your favourite foods to eat at home? M What are your favourite foods when you go out to eat? 3. Make a class list of the top ten processed foods that learners in the class like to eat (e.g. fried chips, crisps, soft drinks, sweets, polony). For the learner task that follows, you will need the label from a packet of Vienna sausages and a cola can.

33

See page 63 for learner task to photocopy

Learner Task Card 8

A hot dog on a white roll with fried chips and a coke is a typical example of a fast-food meal that consists of processed foods

Comparing home-cooked food with processed foods and fast foods

fizzy cooldrink

A. Processed and fast foods 1. Look at the example of the fast foods in the picture. 2. Find a Vienna sausage packet and a cooldrink can. Look at the ingredients written on the package. Then fill in the table, as you did for the traditional meal. (Use the food energy table and the food group diagram to help you.)

B. Comparing a home-cooked meal with a fast-food meal Food ingredient

fried chips

white roll tomato sauce margarine sausage

Food group Other substances added to food

Estimated energy value in kilojoules per single portion

Traditional food: samp and beans Samp

Group 3

salt

Beans

Group 1

437

Onion

Group 2

46

Total amount of energy per meal

485

968 kJ

Processed food: hot dog, coke and chips Vienna sausages

Group 1

Tomato sauce

None of the colourants, flavourants, main food preservatives, salt, sugar, spices groups

19

White roll

Group 3

baking powder, preservative, salt, sugar

400

rising

467

Margarine

Group 3

food colourants, preservative, salt, sugar

150

Fried chips

Group 3

salt

1 292

Coke

Group 3

food colourant, sugar

900

Total amount of energy per meal

34

colourants, flavourants, preservatives, salt, sugar, spices

13 228 kJ

C. Comparing the two kinds of meals Discuss the difference between the two kinds of meals. 1. Which meal includes all three food groups?

Samp and beans/traditional meal 2. Which meal contains the most added salt, sugar and chemicals?

Hot dog, coke and chips/the processed food. 3. Which food group provides the most kilojoules in each meal?

Group 3 - the carbohydrates fats and oils 4. Write sentences to compare these two meals.

Comparing home-cooked food with fast foods The home cooked meal is made from food which only has salt added to it. The fast food meal has had many chemicals added to it. The main difference is that the traditional home-cooked meal is made with food from all three food groups. The food is not processed very much. The processed meal has no food from group 2 (vitamins, minerals and fibre). The kilojoule (energy) content is extremely high. This is because the potatoes are fried in oil and the cooldrink contains a lot of sugar. The processed meat contains very little fibre because most of the fibre has been removed. 5. Which meal would you choose? Why? Would you eat it every day? Would this be good for you? Explain why or why not. Learners’ answers will vary. Encourage all reasonable answers. The Food Energy Table Food

Amount

The food groups Kilojoules (kJ)

Sugar, white

1 teaspoon

64

White bread

1 slice, 40 g

300

Jam

1 table spoon

557

Peanut butter

1 tea spoon

123

Cooked beans

1/2

437

Margarine

1 teaspoon

152

Egg

1 boiled

379

Potato

1 large boiled

Potato chips fried in oil

1 small serving

Cola

500 ml

900

Diet cola

500 ml

0

Potato crisps

1 packet 30 g

668

Chicken, fried in oil

1 drumstick

774

Pie, Chicken

1 small pie

2431

Biscuit

1 lemon cream

300

White rice

1/2

cup cooked

435

Maize meal porridge

1/2

cup, stiff (cooked)

Chocolate (milk)

1 bar, 100 g

Meat (mutton stew)

1/2

cup

865

Spinach

1/2

cup = 85 g, cooked

82

Pumpkin

100 g boiled

176

Oil

1 teaspoon

184

Samp

1/2

485

Onion

1 cooked

cup = 85 g

cup cooked

Group 3: Carbohydrates, fats and oils – energy foods

293 955

463 2241

Group 1: Proteins – bodybuilding foods

Group 2: Vitamins and minerals – protective foods

46

35

Consolidation 1. Explain the following to the learners.

People in cities eat too much processed food and food from which the fibre has been removed (called refined food e.g. white flour and white bread). They also eat too much sugar, fat and salt. This can lead to health problems such as heart disease, cancer, high blood pressure and other ailments.

Dangerous eating habit

Possible diseases as a result

Eating too much fat and sugar

Obesity (being too fat) High cholesterol leading to heart disease

Eating too much sugar and refined foods

High blood sugar, eventually leading to diabetes

Eating too much refined food

Digestive problems, eventually leading to colon cancer

Eating too much salt

High blood pressure which can cause strokes and heart attacks

Eating too much sugar and foods containing preservatives and colourings

Serious allergies, problems with concentrating and studying, learning problems

2. Give the learners the following task: M Imagine yourself 100 years from now. What types of food will you be eating? Why? Where do you think the food will come from? How nutritious will it be? Draw and write to tell about this.

36

10 Key concepts M

M

M

M

We need food for energy, to move, to grow and to repair damage to our bodies. We need a balanced diet from all three food groups to stay healthy. We need food that is fresh and good for us and that has not lost its nutritional value during processing. We need to choose to eat the most healthy foods for our bodies.

Eating a balanced diet Teacher task Assessment task (LO3) 1. Ask leading questions to find out what learners know, or explain the points through discussion. Some questions you may ask are: M Where do we get our food from? M What do we need from our food? M What kinds of food give us the things we need? M Why do people buy processed food? M What is processed food? What does it have added to it? M Why should we avoid processed foods? M What makes you want to buy a food product?

The discussion should lead to the following points: M We get food to eat from our environment. M Food is digested slowly in your stomach. Digestion releases glucose sugar into your blood over a long period of time. M We need to eat fresh, nutritious food which is processed as little as possible. M Most people in cities buy their food from a shop or supermarket. M Most food in shops is processed and packaged so that it lasts longer. It is also processed to make it taste better. M Many luxury and snack foods taste nice because they have had fat, sugar and chemical flavourings added. M Processed food can be difficult for our bodies to digest because they contain too little of the substances our bodies need (fibre, minerals and vitamins) and too much of substances that can damage our bodies (fat, salt, sugar and chemicals). M Food manufacturers have to print information about the ingredients on the food packages. It is our responsibility to read and use that information. M Attractive labels and advertisements on packaging can influence which foods we buy, but it is important to check what the food contains. M We can keep our bodies healthy by choosing to eat the food that we know is good for us M Luxury foods are usually those that are highly processed. They have had sugar or salt and fat added to them and they are expensive. For example, chocolates, very rich cheeses, cream cakes, pastries, sweets, expensive processed meats such as salami, etc. Avoid describing food as ‘healthy’ or ‘unhealthy’, as these terms are relative. Any food eaten in excess can lead to health problems. Similarly, fast foods are not damaging to our health if we only eat them occasionally. Instead compare foods, asking questions such as: Which should we eat regularly? Which should we only eat sometimes? Which is high in fat? Which is high in fibre? Why should we eat this more often than that? And so on.

2. Ask learners to bring examples of food packets and examples of different foods they eat. They must read the information on the food packets and then decide whether the foods are ones they should eat often or not. For example, on the bread packet that follows, the bread contains all three food groups and few chemicals. So your learners might conclude that bread is good to eat often.

37

Learner task Assessment task for LO3

Making better food choices A. Read the food labels Collect examples of food packaging, pictures of food, and samples of different foods that you eat. Here is an example of a bread packet and how to read it.

This tells you how much energy the bread contains.

The bread contains these substances.

Preservatives are chemicals that prevent bread from going bad.

The recommended daily allowance (RDA) indicates how much of each substance a person over 13 years old should eat per day.

38

B. Make a poster to compare healthier and less healthy food choices 1. Read the food packets that you have brought to find out: a) the nutritional value of the food (how many kJ each serving contains) b) the food groups it belongs to. Also use the food group diagram. Decide whether the food is something you should eat more often or less often. 2. Before you put your food on the poster, tell your group which side you will put it on and why. Next to each food write the reason why you think that it is more or less healthy. Make sure that you include examples of the three main food groups.

C. Write a paragraph to answer each question below. 1. Why do we need a healthy diet for our bodies? 2. How can you make your own diet healthier?

Suggested guide for assessment of LO3 Assessment task

Assessment criteria: LO3

A. Make a poster to compare Presentation healthy and unhealthy food The learner must... choices I Lay the poster out clearly I Write neatly and legibly I Use pleasing overall presentation Content I Provide examples of foods from all three food groups I Use at least five relevant examples of healthy and unhealthy foods I Show understanding of healthier and unhealthier eating habits To achieve code 4 (80%)

I Write their reasons extremely logically and clearly and show a

complete understanding of which foods they should eat regularly and which foods they should avoid B. Write two paragraphs to explain:

I Why we need a healthy diet for our body environment I How you can make your own diet more healthy I Show understanding of the concept of a healthy diet and its

relation to the life processes I Include at least three relevant suggestions about how to improve their own diet To achieve code 4 (80%)

I Show a personal sense of responsibility and commitment for

taking care of their own health by choosing healthier foods over less healthy foods

39

Consolidation Ideas for projects M

M

M

M

Find out about a food garden project in your area and take your class to visit it. Start a food garden project at your school. Make a difference by finding ways to help people who do not have enough food. Contact organisations such as SEED for help to grow food gardens. PO Box 40 Philippi 7781, Tel: 371 3180 or 447 7686

1. Discuss the following questions with the class: M Why is it a good idea to eat more traditional foods? M Why do we process some foods? M What gets removed or added to foods during the processing? M What is luxury food? M What health problems can we get from eating too many luxury and processed food? M Who should decide what kind of food we eat? M Why is it important to choose our food carefully? M How does our food affect our bodies?

Extension activity for LO3 Read the articles that follow on the next few pages. Discuss these questions with your class: M Why do we like to eat luxury foods such as chocolates, chips and sweets? M Do you know anyone in your family, or your community who is suffering from a diet-related disease? What useful suggestions could you give them? M Do you know of any family or community members who are not getting enough food? How can you help them? M What suggestions can you give your family about choosing good food that will not cost too much? M What do you bring or buy to eat at school? Is it enough? Is it healthy? M Does your school get food from the school-feeding scheme? What food does your school get? Is it healthy? Why?

Processed foods take a bite out of city’s health

Cape Town has a higher rate of lifestylerelated illnesses than most other cities in the country. A two-month study found that Cape Town has the highest rate of diabetes and the second highest rate of heart disease and strokes in men. Researcher Adam Cooke led a study which surveyed nine cities in South Africa. Polokwane in Limpopo came out tops with the fewest lifestyle-based illnesses. Cooke discovered that Cape Town has shocking health statistics. He found that people eat very poorly and do not exercise enough. He says that even those who had moved from rural areas were changing their relatively healthy diet to one with less fibre. “These are

40

diseases of lifestyle. “Many people move into Cape Town from the rural areas, looking for jobs. These people change their healthy rural diet drastically once they move to the city. People eat less fresh produce in the city because it is easier to buy processed food. Also, there is less land available to people for growing their own vegetables. Lunelle Arendse, a dietician from the Heart Foundation, says that diabetes is often the consequence of not taking responsibility for health and not cultivating healthy lifestyle habits,” says Cooke. Adapted from an article in Cape Argus, 21 November 2005

Isijabane Semifino Yembuya (Wild pumpkin leaves, pumpkin and mielie mix) 1 small pumpkin, cubed 140 g wild pumpkin leaves 250 g fresh mielies, crushed 2 chilli peppers, finely chopped 750 ml water salt to taste Bring water to the boil. Add pumpkin, wild pumpkin leaves, crushed mielies and chilli peppers. Cook until soft, stirring occasionally. Add salt and simmer for a few minutes. Serve hot. Taken from: South African Indigenous Foods (IndiZAFoods)

Luxury foods and diseases Many people choose foods that are refined and high in fat and sugar, because they are easy to eat and taste sweet. Chocolate, cakes, puddings, biscuits and sweets all taste sweet. They are easy to digest and high in kilojoules. They are also easy to eat because they are already prepared. However, eating too much sugary, fatty food is dangerous because it can lead to illnesses, such as: I obesity – becoming dangerously overweight; can lead to other diseases I diabetes – when the body cannot control the amount of sugar in the blood I high cholesterol and heart disease – the body stores the fat in the veins and arteries, which causes them to get blocked; this can lead to heart attacks I high blood pressure - this can lead to strokes and heart attacks I allergies – these can lead to asthma and skin problems can be

caused by eating too much sugar, refined white flour and chemical preservatives such as sodium benzoate I behaviour problems – eating too much sugar, refined white flour and chemical preservatives and flavourings such as tartrazine can lead to hyperactivity and inability to concentrate. Also, foods that are high in fat and sugar give you a very quick burst of energy. A short while later, you will

feel quite tired. Luxury foods are highly processed foods. They can be delicious sometimes, but they should not form the main part of your diet. M a n y people have problems with food. These problems often affect young people. Some young people overeat (eat too much) and others undereat (eat too little). People that overeat may eat certain foods for comfort when they are facing personal difficulties. Some people eat a lot of sugary, fatty food when they are depressed, lonely, scared or don’t feel good about themselves. Often, they try to make themselves feel better by eating snacks, sweets and fast foods. Some people get addicted to these “comfort foods”. This addiction becomes a kind of mental illness.

41

The Secrets of African Women

T

he government has provided money to publish a recipe book called “South African Indigenous Foods”, which includes recipes for meals from all regions of South Africa. When European settlers landed in South Africa, they discovered that the indigenous people had remedies for many kinds of diseases. Indigenous people also knew how to farm effectively, and they knew about good nutrition. Today, researchers recognise that women in traditional communities manage the natural resources around the home – for example the garden. Women usually know and understand their environment and use it as a source of traditional remedies. They are also the ones who keep this knowledge alive, using it and passing it on from generation to generation. In a community, women usually keep the cultural traditions alive. We say that women are the keepers of indigenous knowledge. Today, many people are realising that indigenous foods are very important. For centuries, Africans have kept their families healthy by using the food and natural medicines available to them. African women learnt about the nutritional value of the foods by cooking for their families and developing recipes which form the staple of African diet. In the past, Europeans did not realise that these traditional African foods are highly nutritious. As obesity and diet-related diseases increase in South Africa, people are concerned that a healthy, traditional way of eating is disappearing. The recipe book aims to bring traditional foods back to our tables. Adapted from: Mail and Guardian 12–18 August 2005

42

43

LESSON 2

Activity 2 • Teacher and learners construct a mind map about plants and their uses. • Learners copy mind map into their books.

LESSON 7

Activity 5 • Teacher explains photosynthesis using a diagram. • Teacher prepares learners for the assessment task.

LESSON 12

Activity 7 cont. • Learners bring more foods from home and test them for starch. • Consolidation: class discussion.

LESSON 17

Activity 9 cont. • Learners present their recipes from home.

LESSON 22

Activity 10 Assessment task for LO3 • Teacher explains points about food. • Teacher helps learners to read food packets to find nutrition information.

LESSON 1

Activity 1 • Teacher introduces the 7 life processes. • Learners write sentences and act out the processes.

LESSON 6

Activity 4 • Teacher explains van Helmont’s experiment. • Consolidation: class discussion about the experiment.

LESSON 11

Activity 7 • Teacher explains that plants make many substances and that foods contain a mixture of food substances. • Learners do starch tests on different foods.

LESSON 16

Activity 9 cont. • Teacher and learners analyse the homecooked meal. • Learners prepare to find a recipe for a traditional meal in their cultures.

LESSON 21

Activity 7 cont. • Learners finish their group graphs. • Learners discuss and answer questions.

Suggested work schedule

Activity 10 cont. • Learners bring food and pictures from home. • Learners make poster about good food choices.

LESSON 23

Activity 9 cont. • Teacher introduces concept of processed foods. • Learners compare a home-coked meal with fast food meal.

LESSON 18

Activity 7 cont. Assessment task for LO1 • Teacher helps learners to clarify questions for investigation. • Learners prepare to carry out their survey. • Learners will do the rest of the task after one week to allow learners to do survey.

LESSON 13

Activity 5 cont. (Assessment task for LO2) • Learners do assessment task for LO2. • Teacher must make time to give feedback to learners about the assessment task.

LESSON 8

Activity 3 • Learners complete a table about food and plants. • Teacher assists learners to read the information about sustaining food plants

LESSON 3

Activity 10 cont. • Teacher gives feedback about posters. • Consolidation: class discussion.

LESSON 24

Activity 9 cont. • Consolidation: discussion about dietrelated diseases. • Learners draw and write about foods in the future.

LESSON 19

Activity 8 • Teacher reads the poem “Thank you for my slice of bread”. • Learners write their own “thank you” poem. • Learners say their poems.

LESSON 14

Activity 5 cont. • Consolidation: Learners write a recipe for photosynthesis.

LESSON 9

Activity 3 cont. • Learners answer questions about the reading. • Teacher checks the answers with learners.

LESSON 4

Activity 10 cont. • Some learners do the extension task for LO3. • Teacher helps other learners to complete all previous work.

LESSON 25

Activity 7 cont. • Learners bring results of their starch food survey and draw graphs of their results. • Learners fill in group results and draw a group graph.

LESSON 20

Activity 9 • Teacher explains about healthy foods and the 3 food groups. • Learners read the recipe for a homecooked meal. • Teacher explains benefits of homecooked meals.

LESSON 15

Activity 6 • Teacher explains how to test a leaf for starch and demonstrates the test. • Learners test green leaves for starch. • Consolidation: teacher asks questions. and reads poem about food factories.

LESSON 10

Activity 3 cont. • Teacher reads article about GM foods. • Consolidation: class discussion.

LESSON 5

SECTION 2 SECTION 2 Teacher resources Learner task cards to photocopy Task card 1 What do all living things do and need? . . . . . . . . . . . . . . . . . . . . . . . 46 Task card 2 What foods do we get from plants? . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Task card 3 Sustaining our food plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Assessment task for LO2 Understanding the process of photosynthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . Task card 4 Write a recipe for photosynthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . Task card 5 Test a green leaf for starch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Task card 6 Test different foods for starch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

51 53 54 55

Assessment task for LO1 Investigating staple foods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Task card 7 Analysing home-cooked meals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Task card 8 Comparing home-cooked food with processes foods . . . . . . . . . . . 63

Assessment task for LO3 Making better food choices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Task card 9 Reflecting about Life and Living . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information on GM foods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Poem in Isixhosa: UMNGA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Story in Afrikaans: Dirkie mens en snytjie brood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

67 68 69 70

Teaching aids for photosynthesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

45

TASK CARD 1 Task card to photocopy Learner task What do all living things do and need? 1. Complete the picture, What does my body need to carry out its life processes? Draw pictures and make labels to show the seven life processes.

What does my body need to carry out its life processes?

46

TASK CARD 1 (CONT)

Task card to photocopy

2. Write sentences to explain what your body needs to carry out each process.

MOVEMENT e.g. My body needs to eat and digest food to give me energy. .................................................................... ....................................................................

RESPIRATION .................................................................... ....................................................................

SENSITIVITY .................................................................... .................................................................... ....................................................................

GROWTH .................................................................... .................................................................... ....................................................................

REPRODUCTION .................................................................... .................................................................... ....................................................................

EXCRETION .................................................................... ....................................................................

NUTRITION .................................................................... .................................................................... ....................................................................

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TASK CARD 2 Task card to photocopy Learner task What foods do we get from plants? What foods do you eat regularly?

What plants do these foods come from?

Fried chips, mashed potato Bread Salad Sugar cane Cabbage Lentils, beans or chick peas Chocolate Oil Tea bush Spinach Onion

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TASK CARD 3 Learner task Sustaining our food plants

Task card to photocopy

Food for our bodies To stay healthy, we need to eat a balanced diet. A balanced diet contains foods from the main groups. The main food groups are: carbohydrates, proteins, minerals and vitamins, fats and oils, and fibre. M Carbohydrates give us energy. We get them from starchy foods such as bread, rice and potatoes. M Proteins help our bones to grow. We get them from foods like meat, eggs, milk, beans and nuts. M Minerals and vitamins are found in fruits and vegetables. They help us to fight diseases. M Fats and oils help our skin and hair to stay healthy. We get them from butter, margarine, oil and nuts. M Fibre helps our digestion. Fibre is the hard, chewy part of plants such as apples, pumpkin and wheat. Staple foods All around the world the main food that people eat is called their staple food. Staple foods provide people with the main carbohydrate (starchy) part of their diet for each day. Staple foods give us energy. Some of the important staple foods around the world are rice, maize and wheat. In most places, people eat the staple foods that grow most easily in their areas. In South Africa, our staple foods are maize, wheat and potatoes. In West Africa, cassava and yam are staple foods. In Asia, rice is a popular staple food. Sorghum, oats and sweet potatoes are also staple foods in some areas of the world where they grow. People who live in cities can eat a variety of staple foods from around the world, which they can buy in shops. Grass feeds the world! Almost all the staple foods come from plants that belong to the grass family. Maize, wheat, rice, oats, rye, barley and sorghum all come from kinds of grasses. The sugar cane plant is also a grass. We also get our meat and milk indirectly from grasses because cows, goats and sheep all feed on grass. Traditional foods Traditional foods come from local crops. Farmers collect the seeds from their crops each year to plant the next season's crops. This helps them to sustain the crop (keep it going year after year). Some traditional foods grow wild and seed themselves, for example, wild spinach (umfino), marula fruit, prickly pears, msoba-soba berries, sour figs (suurvye) and blackberries all grow wild. Traditional foods can provide us with important minerals and nutrients. Foods in shops are not as fresh. When they get packed and transported, they lose a lot of their minerals and nutrients.

49

TASK CARD 3 (CONT.)

Task card to photocopy

Learner task Improving the harvest Farmers often try to increase the amount of food that they can harvest from their crops. They add manure or fertilisers to the soil to provide their crops with mineral salts. They also use chemicals to control pests and diseases, which can attack their crops. We all depend on farmers to sustain our food plants around the world.

Questions a) What is a ‘staple food’? b) What important food group is found in all staple foods? What do we need it for? c) What family of plants provide most of the world’s staple foods? d) What do we mean by a traditional food? e) What do farmers do to increase the amount of food from their crops? f) Name some traditional foods that grow wild. Say which ones you have eaten.

50

Assessment task for LO2

Task card to photocopy

Understanding the process of photosynthesis A. Read and discuss the information about photosynthesis below. In the sunlight

Green plants absorb ……………………………………… from the sun. In the roots

The roots take up ……………………… and ………………………………………… from the soil into the plant. In the leaves

Leaves absorb the gas ……………………… Plants make a food called ……………………… Then the plants convert glucose sugar to ………………………… so that they can store it Leaves release …………………………………… into the air. In the plant

Plants store the sunlight energy as food (starch) in their ………………………………………………………………………

In the environment

Humans and animals ………………… plants for food. Humans and animals breathe out ……………………………………………… Humans and animals breathe in ……………………………………………

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Assessment task for LO2 (cont.) B. Use the drawing below (or make your own) to show the process of photosynthesis. On your drawing make arrows and write labels to show where: M Sunlight energy goes M Water and mineral salts go M Carbon dioxide goes M Oxygen goes M The plant makes glucose sugar and starch

C. Write a few sentences to explain why photosynthesis is important for life on Earth. ........................................................................... ........................................................................... ........................................................................... ...........................................................................

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Task card to photocopy TASK CARD 4 Learner task Write a recipe for photosynthesis Pretend you are an old plant telling a young plant how to make starch.

A recipe for starch How to make glucose and starch Ingredients What substances do you need to make this food?

........................................................................... ........................................................................... ........................................................................... ........................................................................... Method What steps must you follow to make the food? 1.

.................................................................

2.

.................................................................

3.

.................................................................

4.

.................................................................

5.

.................................................................

Questions a) What is left over after the plant has made glucose and starch?

........................................................................... ........................................................................... b) Where does this leftover substance go and who uses it?

........................................................................... ........................................................................... c) Where does the plant make its food?

........................................................................... ...........................................................................

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TASK CARD 5

Task card to photocopy

Learner Task SAFETY PRECAUTION! Do not work with ethanol or methylated spirits near an open flame. It is highly flammable and may explode.

Test a green leaf for starch Follow the instructions in the diagrams below. Then answer the questions that follow. 1. Put a leaf in a baby food jar. Cover it with boiling water and leave for 2 minutes. Boiling water destroys the membranes of the cells.

1

2. Put the leaf in a baby food jar. Cover it with methylated spirits (or ethanol). The methylated spirits removes the green chlorophyll from the leaf. After a while, the leaf should be white or pale green and hard.

boiling water 2&3

baby food jar leaf

3. Place the baby food jar in styrofoam cup of boiling water.

hot water methylated spirits

4. Dip the leaf in hot water. Hot water makes the leaf soft again.

5. Put the leaf on a square piece of waxed lunch wrap (or a plastic lid). Put a drop of iodine solution onto the leaf. The iodine will turn black where starch is present.

Questions

4 styrofoam cup with boiling water

5

rinse in hot water

iodine solution

a) Did we find starch in the leaves we tested? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . b) How could we tell that there was starch in the leaf? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .................................................................. c) What does iodine do when starch is present? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .................................................................. d) Where do plants make their food? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..................................................................

54

TASK CARD 6 Task card to photocopy Test different foods for starch A. Make predictions. 1. What colour is your iodine solution? ………………………………………………………………

2. What colour will your iodine turn when you drop it onto a starchy food? ………………………………………………………………………………………………………

3. List the foods that you think will contain starch: ………………………………………………………………………………………………………

………………………………………………………………………………………………………

………………………………………………………………………………………………………

………………………………………………………………………………………………………

………………………………………………………………………………………………………

………………………………………………………………………………………………………

………………………………………………………………………………………………………

………………………………………………………………………………………………………

B. Test different foods. 1. Put a small sample of each food in a plastic bottle top. Make sure that different foods do not touch each other. 2. Test each food with a drop of iodine. Do not touch the food with the dropper as this could contaminate the other foods. 3. Record your observations in the table.

55

TASK CARD 6 (CONT.) Food

Plant it comes from

Task card to photocopy Colour when iodine is added

Is starch present?

Maizena Sugar Cheese Flour Egg white Cooking oil Potato Cooked beans Bread Rice Oats porridge Pasta Banana Carrot Onion

4. Were your predictions correct? ………………………………………………………………

C. Write a conclusion with your teacher We learnt from this experiment ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ………………………………………………………………………………………………………

56

Assessment task for LO1 Learner task

Task card to photocopy

Staple foods

A. Discuss questions for investigation 1. What makes a food a staple food? 2. How did you find out which foods contain starch? 3. Which foods do you know definitely contain starch? 4. How would we decide which of these starchy foods are staple foods? In your groups write down some questions to ask your family to find out what staple foods they eat regularly. ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… 5. Discuss which starchy foods you eat most often yourself. These are your staple foods.

B. Conduct investigations, collect and record data 1. Do a survey. a) Bring some foods you eat often at home to test for starch. Identify which are the staple foods for your family. Give reasons that you think they are staple foods. ………………………………………………………………………………………………… ………………………………………………………………………………………………… 2. Now that you know which foods are carbohydrate foods (contain starch), carry out a survey about the following carbohydrate foods: 3. Count how many times a day you eat each carbohydrate food. Then complete the table below. Add more lines to the table if you need to add more examples. 4. Work out the total amount of staple foods for a week. Then record it on the table.

Jane’s staple foods Staple food

Mon

How many times I eat these foods each day Tues

Wed

Thu

Fri

Sat

Sun

Total

Potato Rice Mielie meal Bread Pasta

57

Assessment task for LO1 (cont.) Learner task

Task card to photocopy

5. Show your findings in a bar graph.

Graph to show how many times a week I eat each starch food

Total number of times that I eat starchy food each week.

30

25

20

15

10

5

0 Different starchy foods

3. Copy and complete the table below for your group, to show how many times a week each person in your group eats the carbohydrate food. 4. Draw a bar graph for each group using the total number of times your group eats each starchy food. Number of times a week I eat this food Number of times carbohydrate food (starch food) is eaten each week Potato Rice Mielie meal Bread Pasta

58

Name

Name

Name

Name

TOTAL

ASSESSMENT TASK FOR LO1 (CONT.)

Task card to photocopy

Learner task Graph to show how many times a week our group eats each starchy food

Total number of times each food is eaten in our group

30

25

20

15

10

5

0 potato rice mielie meal bread Different starch foods

C.

pasta

Evaluate and interpret data

Discuss these questions in your group. Then write answers to the questions on your own. 1. Explain what we mean by a staple food. 2. Look at your graphs. Compare them and decide what is the staple food for each person. 3. Does every person have the same staple food? Give reasons. 4. Compare the staple foods for the learners in your class. What can you say about staple foods in your class? 5. How easy was it to count the number of times you ate staple foods during the week? 6. Do you think your counting was accurate? 7. How could you have improved this survey to make it more accurate?

59

TASK CARD 7

Task card to photocopy

Learner task A. Analysing home-cooked meals 1. Look at the food energy table and the three food groups. Use the information from the table and the diagram of the different food groups, to help you fill in the table.

Ingredients Samp Beans Onion

Food groups

60

Food group/s

A meal of umngqusho onembotyi (samp and beans)

Energy

Substances added to the food

TASK CARD 7 (CONT.)

Task card to photocopy

Learner task Food energy table Food

Amount

Kilojoules (kJ)

Sugar, white

1 teaspoon

64

White bread

1 slice, 40 g

300

Jam

1 table spoon

557

Peanut butter

1 tea spoon

123

Cooked beans

1/2

437

Margarine

1 teaspoon

152

Egg

1 boiled

379

Potato

1 large boiled

293

Potato chips fried in oil

1 small serving

Cola

500 ml

900

Diet cola

500 ml

0

Potato crisps

1 packet 30 g

668

Chicken, fried in oil

1 drumstick

774

Pie, Chicken

1 small pie

2431

Biscuit

1 lemon cream

300

White rice

1/2

cup cooked

435

Maize meal porridge

1/2

cup, stiff (cooked)

463

Chocolate (milk)

1 bar, 100 g

Meat (mutton stew)

1/2

cup

865

Spinach

1/2

cup = 85 g, cooked

82

Pumpkin

100 g boiled

176

Oil

1 teaspoon

184

Samp

1/2

485

Onion

1 cooked

cup = 85 g

cup cooked

955

2241

46

61

TASK CARD 7 (CONT.)

Task card to photocopy

Learner task B. Foods in the past, present and future 1. Find out about foods your parents or grandparents used to make at home. Speak to members of your family or community to find a recipe of a traditional meal in your culture. 2. Write and draw the recipe, using the following headings: M Name of food or meal M Ingredients M Method (what to do) 3. Then share the foods and recipe you have written. Include any interesting details about the foods and when and how you eat them.

Recipe

............................................. ............................................. ............................................. ............................................. ............................................. ............................................. ............................................. ............................................. ............................................. ............................................. ............................................. ............................................. ............................................. ............................................. 62

TASK CARD 8

Task card to photocopy

Learner task Comparing home-cooked food with processed

foods and fast foods A. Processed and fast foods 1. Look at the example of the fast foods in the picture. 2. Find a Vienna sausage packet and a cooldrink can. Look at the ingredients written on the package. Then fill in the table, as you did for the traditional meal. (Use the food energy table and the food group diagram to help you.) Food ingredient

Food group Other substances added to food

Estimated energy value in kilojoules per single portion

Traditional food: samp and beans Samp

Group 3

salt

Beans

Group 1

437

Onion

Group 2

46

Total amount of energy per meal

485

968 kJ

Processed food: hot dog, coke and chips Vienna sausages

Tomato sauce

White roll

Margarine

Fried chips

Coke

Total amount of energy per meal

13 228 kJ

63

TASK CARD 8 (CONT.)

Task card to photocopy

Learner task Group 1: Proteins – (body-building foods) Group 2: Vitamins and minerals – (protective foods) Group 3: Carbohydrates, fats and oils – (energy foods)

C. Comparing a home-cooked meal and a fast food meal 1. Which meal includes all three food groups?

............................................. ............................................. 2. Which meal contains the most added salt, sugar and chemicals?

............................................. ............................................. 3. Which food group provides the most kilojoules in each meal?

............................................. ............................................. 4. Write sentences to compare these two meals. For example: The home cooked meal is made from food which only has salt added to it. The fast food meal has had many chemicals added to it.

............................................. ............................................. ............................................. 5. Which meal would you choose? Why? Would you eat it every day? Would this be good for you? Explain why or why not.

............................................. ............................................. ............................................. ............................................. 64

Assessment task for LO3 Learner task

Task card to photocopy

Making better food choices

A. Read food labels 1. Work in groups. Collect examples of food packaging, pictures of food, and samples of different foods that you eat. Here is an example of a bread packet and how to read it.

This tells you how much energy the bread contains.

The bread contains these substances.

Preservatives are chemicals that prevent bread from going bad.

The recommended daily allowance (RDA) indicates how much of each substance a person over 13 years old should eat per day.

65

Assessment task for LO3 (cont.)

Task card to photocopy

Learner task B. Make a poster to compare healthier and less healthy food choices. 1. Read the food packets that you have brought to find out: a) the nutritional value of the food (how many kJ each serving contains). b) the food groups which the food belongs to. Also use the food group diagram. Decide whether the food is healthier or less healthy. 2. Before you put your food on the poster, tell your group which side you will put it on and why. Next to each food write the reason why you think that it is more or less healthy. Make sure that you include examples of the three main food groups.

C. Write a paragraph to answer each question below. 1. Why do we need a healthy diet for our body?

............................................. ............................................. ............................................. ............................................. ............................................. ............................................. 2. How can you make your own diet more healthy?

............................................. ............................................. ............................................. ............................................. ............................................. .............................................

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TASK CARD 9 Task card to photocopy Learner task Reflecting on Life and Living 1. Write and draw to tell about anything that you found interesting in this work on Life and Living. 2. Explain why you found that part interesting. 3. Also write some questions about anything that you would like to know more about in Life and Living.

............................................. ............................................. ............................................. ............................................. ............................................. ............................................. ............................................. ............................................. ............................................. ............................................. ............................................. ............................................. ............................................. ............................................. ............................................. .............................................

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Information on GM foods

What are GM foods? Genetically Modified (GM) plants are crops that scientists have developed by changing the DNA (the chemical in cells which provides genetic information) in plants and animals. For example some fish have a part of their DNA that helps them to survive in very cold conditions. Scientists have developed tomatoes with some of this fish DNA so that the tomatoes do not get damaged by frost. Scientists encourage farmers around the world to use GM crops. The scientists say that GM foods will help farmers to increase the amount of food that they can produce.

Problems with GM foods M

M

M M M

M

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The scientists are employed by very big companies to do their research. Once they have developed the GM seeds, they sell them to farmers at very high prices. GM seeds are usually very expensive. The scientists alter (change) the plant so that the crops do not produce good seeds of their own. So the farmers have to buy fresh seeds every year. In this way the seed company earns more money. The crops are strong (they resist pests and diseases well), so they survive better than other local plants, causing other local species to die. Local insect and animal populations can get damaged if the GM foods are not good for them to eat. Another problem is that the farmers often stop growing traditional crops. Although some traditional crops do not produce such a high yield, they are sometimes more able to adapt to changes in the climate such as drought. People feel that it is important to sustain (keep growing) many of the traditional crops so they can be used in the future if the climate changes. We are not sure if food produced from GM crops is safe to eat. In many developed countries, people refuse to eat GM crops in case they cause illnesses. Seed companies then try to sell the unwanted seeds to less developed countries.

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SECTION 3 Extracts from the National Curriculum Statements for Natural Sciences Grades R – 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Core knowledge and concepts for Life and Living (NCS) . . . . . . . . . . . . . . . . . . . . . 77 – 81 Learning Outcomes and assessment standards (NCS) . . . . . . . . . . . . . . . . . . . . . . . . 82 – 87

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Natural Science

CORE KNOWLEDGE AND CONCEPTS IN LIFE AND LIVING Life Processes and Healthy Living

Interactions in Environments

Biodiversity, Change and Continuity

Unifying statement: Living things, including humans and invisibly small organisms, can be understood in terms of life processes, functional units and systems.

Unifying statement: Organisms in ecosystems are dependent for their survival on the presence of abiotic factors and on their relationship with other organisms.

Unifying statement: The huge diversity of forms of life can be understood in terms of a history of change in environments and in characteristics of plants and animals throughout the world over millions of years.

Foundation Phase 1 Many of our body parts correspond to parts of animals, such as limbs, heads, eyes, ears, feet, and in many cases animals use them for the same purposes we do. 2 Animals and plants have needs similar needs to ours, for food, water and air.

3 We depend on plants and animals for food, and we breed certain animals and grow certain plants as crops. 4 We see cultural diversity in the kinds of food people like to eat. 5 Some animals, like flies and ticks, carry germs which can make people sick.

6 There is a large variety of plants and animals, which have interesting visible differences but also similarities, and they can be grouped by their similarities. 7 Plants and animals change as they grow, and as the years pass, and as the seasons change.

Intermediate Phase 1 Green plants produce their own food and grow by using water and substances from the air and soil. Energy from light is needed to change these simple substances into food and plant material. Green plants are the only organisms that can produce food in their own bodies.

5 Animals cannot make their own food, and so some animals eat plants for food while some animals eat other animals. All animals ultimately depend on green plants for their food.

10 New plants can grow from certain parts of a parent plant. This is called vegetative reproduction and does not need seeds. The new plants have all the characteristics of the parent plant.

Core Knowledge and Concepts in Matter and Materials

77

Revised National Curriculum Statements Grades R–9 (Schools)

Life Processes and Healthy Living

Interactions in Environments

Biodiversity, Change and Continuity

Intermediate Phase 2 Living things need food for energy, to move, grow and to repair damage to their bodies (‘tissues’). Animals including humans have digestive systems for getting nutrients from food. Humans need a balanced diet from certain groups of food to be healthy. 3 All living things can respond to their environment in various ways; animals, including humans, have specialised sense organs.

6 Ecosystems are selfcontained areas where a wide variety of plant and animal species live and reproduce. They depend on each other and on the non-living environment. The life and reproduction of all the organisms in an ecosystem depend on the continuing growth and reproduction of plants. 7 Organism habitats are the places where they feed, hide, reproduce and, in many cases, shelter the young until they have a better chance of survival. Animal species live in their habitats in a variety of social patterns (such as being solitary, pairing for life, or living in packs, prides, herds or troops). 8 Ecosystems depend on soil. Soil forms by natural processes from rock and dead plant and animal material, but it takes an extremely long time to form. Substances which plants take from the soil must be replaced to main fertility of the soil. (Links with soil in Planet Earth and Beyond)

11 Sexual reproduction is the process by which two individual plants or animals produce another generation of individuals. The next generation’s individuals look like the parents but always have slight differences (‘variation’) from their parents and from each other. 12 South Africa has a rich fossil record of animals and plants which lived many millions of years ago. Many of those animals and plants were different from the ones we see nowadays. Some plants and animals nowadays have strong similarities to fossils of ancient plants and animals. We infer from the fossil record and other geological observations that the diversity of living things, natural environments and climates were different in those long-ago times. (Links with fossils in Planet Earth and Beyond)

Core Knowledge and Concepts in Matter and Materials

78

Natural Science

Life Processes and Healthy Living

Interactions in Environments

Biodiversity, Change and Continuity

Intermediate Phase 4 Living things can move themselves; animals, including humans, can move themselves from place to place. Many species of animals move themselves by means of muscles attached to some kind of skeleton which is either inside or on the surface of the body.

9 Water plays an important role in ecosystems, sustaining both plant and animal life. Industrial, agricultural and domestic activities may have a serious impact on the quality and quantity of water available in an area. (Links with Planet Earth and Beyond)

Senior Phase 1 Humans go through physical changes as they age; puberty means that the body is ready for sexual reproduction. 2 Human reproduction begins with the fusion of sex cells from mother and father, carrying the patterns for some characteristics of each. 3 Conception is followed by a sequence of changes in the mother’s body, and during this period the future health of the unborn child can be affected. 4 Knowledge of how to prevent the transmission of sexually transmitted diseases, including the HIVirus, must be followed by behaviour choices.

10 Human reproduction is more than conception and birth; it involves adults raising children, which requires judgement and values and usually depends on the behaviour of other people in a community and environment. 11 Each species of animal has characteristic behaviours which enable it to feed, find a mate, breed, raise young, live in a population of the same species, or escape threats in its particular environment. These behaviours have arisen over long periods of time that the species population has been living in the same environment.

16 Offspring of organisms differ in small ways from their parents and generally from each other. This is called variation in a species. 17 Natural selection kills those individuals of a species which lack the characteristics that would have enabled them to survive and reproduce successfully in their environment. Individuals which have characteristics suited to the environment reproduce successfully and some of their offspring carry the successful characteristics. Natural selection is accelerated when the environment changes; this can lead to the extinction of species.

Core Knowledge and Concepts in Matter and Materials

79

Revised National Curriculum Statements Grades R–9 (Schools)

Life Processes and Healthy Living

Interactions in Environments

Biodiversity, Change and Continuity

Senior Phase 5 Green plants use energy from the sun, water and carbon dioxide from the air to make food by photosynthesis. This chemical reaction is central to the survival of all organisms living on earth. 6 Animals, including humans, require protein, fat, carbohydrates, minerals, vitamins and water. Food taken in is absorbed into the body via the intestine. Surplus food is stored as fat or carbohydrate. 7 Animals, including humans, have a circulatory system which includes the heart, veins, arteries and capillaries, and which carries nutrients and oxygen to all parts of the body and removes waste products. Oxygen, which is provided by the breathing system, reacts with food substances to release energy. (Links with Energy and Change)

12 All organisms have adaptations for survival in their habitats (such as adaptations for maintaining their water balance, obtaining and eating the kind of food they need, reproduction, protection or escape from predators). 13 An ecosystem maintains numerous food webs and competition for food among different individuals and populations. South Africa has certain ecosystems which have exceptional biodiversity. All uses of these areas must be based on principles of sustainable development. 14 Pollution interferes with natural processes that maintain the interdependencies and diversity of an ecosystem.

18 Variations in human biological characteristics such as skin colour, height, and so on, have been used to categorise groups of people. These biological differences do not indicate differences in innate abilities of the groups concerned. Therefore, such categorisation of groups by biological differences is neither scientifically valid nor exact; it is a social construct. 19 Biodiversity enables ecosystems to sustain life and recover from changes to the environment. Loss of biodiversity seriously affects the capacity of ecosystems and the earth, to sustain life. Classification is a means to organise the great diversity of organisms and make them easier to study. The two main categories of animals are the vertebrates and invertebrates, and among vertebrates the five classes are amphibians, birds, fish, reptiles and mammals.

Core Knowledge and Concepts in Matter and Materials

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Natural Science

Life Processes and Healthy Living

Interactions in Environments

Biodiversity, Change and Continuity

Senior Phase 8 All living things, including humans, have means of eliminating waste products which are produced during life processes. Water plays an important role in this process. 9 Water makes up a large proportion of all living things, and their health depends on water passing through them in various ways, using structures (such as kidneys, skin or stomata) which can fulfil this function.

15 Many biological changes, including decomposition and recycling of matter in ecosystems and human diseases, are caused by invisibly small, quicklyreproducing organisms.

20 Human activities, such as the introduction of alien species, habitat destruction, population growth, pollution and over-consumption, result in the loss of biodiversity. This becomes evident when more species become endangered, or, ultimately, extinct. 21 Extinctions also occur through natural events. Mass extinctions have occurred in the past suggesting that huge changes to environments have occurred. However, these changes occurred very slowly, compared to the fast rate at which humans can destroy plant and animal species. (Links with Planet Earth and Beyond) 22 The cell is the basic unit of most living things, and an organism may be formed from one or many cells. Cells themselves carry on life processes such as nutrition, respiration, excretion and reproduction, which sustain the life of the organism as a whole.

Core Knowledge and Concepts in Matter and Materials

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Learning Outcome 3: Science, Society and the Environment The learner will be able to demonstrate an understanding of the interrelationships between science and technology, society and the environment.

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WESTERN CAPE PRIMARY SCIENCE PROGRAMME TRUST (PSP) The PSP is an in-service education organisation that supports primary school teachers in the field of Natural Sciences and related learning areas particularly in township primary schools in the Western Cape. We are based at the Edith Stephens Wetland Park, Philippi, situated close to many disadvantaged communities in the Cape Flats. The PSP has been operating since 1984 and has built up good relationships with over 200 primary schools from all the township areas, including the Boland and West Coast rural areas. More than 1050 teachers from grades 4 to 7 and 126,000 children benefit from the work of the PSP. The PSP works in an environment where most teachers and learners have to operate in a 2nd or 3rd additional language. We therefore also work on developing learners’ communication skills while focusing on science related learning areas and environment. The PSP currently operates with a complement of 9 staff.

CONTACT DETAILS Western Cape Primary Science Programme (PSP) Edith Stephens Wetland Park Lansdowne Road Philippi, Cape Flats, 7785. P.O. Box 24158 Lansdowne 7779 South Africa Tel: (021) 6919039 ( Fax: (021) 6916350 e-mail: [email protected] (website: www.psp.org.za) NPO: 015-822 Registration Number: IT2806/99