The lower epidermis protects the cells inside the leaf. The spongy layer has lots of air spaces. The cells in the spongy layer do a small amount of photosynthesis. A stoma plural: stomata is a tiny hole in the lower epidermis. These holes let carbon dioxide from the air get into the leaf. Activity 1. SE Take a fresh, green leaf. Push the leaf into some warm water. Watch carefully to see where air bubbles appear on the leaf surface.
Questions A1 On which surface of the leaf did most bubbles appear? A2 The bubbles contained gas that came out from inside the leaf. Which part of the leaf do you think the gas came from? Look at the diagram of the inside of the leaf above. A3 Suggest how the gas got out of the leaf. A4 Use what you know about the effect of heat on gases to explain why the gases came out of the leaf when it was put into warm water. One of the simplest ways is to check if it is giving off releasing oxygen gas.
This is easiest to do if the leaf is under water, because the oxygen gas makes bubbles. You can use any plant that grows under water. You can usually get pond weed at a pet shop, because people buy it to put into fish tanks.
If you live near the sea, you can use seaweed instead. If it is very warm and sunny, you may see the gas collecting quickly. If it is colder and not so bright, you may need to leave it for a day to give time for the gas to collect. Put your thumb over the opening, taking care to keep the test tube under water. Try not to touch the wet sides, or you will put it out!
Questions A1 Explain why you needed to use a water plant for this experiment. A2 Explain why you needed to leave the apparatus in a light place. A correlation is a relationship. If there is a correlation between light intensity and photosynthesis, then we would expect that changing the light intensity will result in a change in the rate of photosynthesis. Here are some ideas you can use. For example, you can measure the depth of gas that collects in the test tube in one hour. For a quicker experiment, you can count how many bubbles the weed gives off in one minute.
For a lower light intensity, place the lamp further away. Make changes to your plan if you think you can improve it. But, for many plants, the roots take up just as much space as the above-ground parts of the plant.
Functions of roots The roots of a plant have several functions. These are then transported to all the other parts of the plant. Only the underground roots continue to live. New shoots above-ground parts grow from the roots when conditions become better.
For a plant, its roots are just as important as its leaves. The plant stores the food for its own use, but we can also eat this food. Choose two different roots that humans eat as food. For each root, find out what the complete plant looks like. Make a labelled drawing of the plant. Describe how we use the root for food. How roots absorb water and minerals Soil is made up of tiny rock particles. There is usually water in the spaces between the particles. There are minerals dissolved in the water.
You may remember that special cells called root hairs grow out of the surface of roots. Root hair cells provide a really big surface through which water and minerals can be absorbed. You can see that it is covered with thousands of tiny root hairs.
CUP CP 8 1. SE 1 Take a tall glass jar. Roll up a piece of strong absorbent paper so that it fits inside the jar. Add a little water and allow it to soak into the paper. Carefully put them between the paper and the side of the jar.
Place each one a different way up. Check it each day to see if it needs more water — it is important to keep the seeds moist but not too wet. Questions A1 What do you notice about the directions the roots have grown in? A2 Suggest how this would help a bean plant to survive.
How are these transported from the roots to all the other parts of the plant? If possible, choose one that has some leaves at the top. Stand the celery stalk in the dye. Make sure you stand the stalk the right way up. You should be able to see the coloured dye moving up inside it. This can sometimes happen very quickly and sometimes very slowly, so be prepared! Look at the cut end using a hand lens. Make a drawing of what you can see.
Questions A1 Suggest why it is important to wash the celery stalk before cutting across it. A2 Flowering plants, such as celery plants, contain long tubes called xylem vessels. These vessels transport water and substances dissolved in the water.
Use your results to describe where the xylem vessels are in a celery stalk. SE You are going to plan and carry out an experiment to try to answer the question in the title. Think about the following questions. What variable will I change? How will I change it? What will I measure? How will I measure it? When will I measure it? What variables will I try to keep the same? How will I keep them the same? Are there any safety risks in my experiment?
If so, how can I keep safe? How will I record my results? Can I draw a graph? If so, what will I put on the graph axes? After you have done your experiment, identify the trends and patterns you can see. Compare your results with your predictions. It stayed inside the xylem vessels. Xylem vessels are long, hollow tubes that carry water and minerals from the roots of the plant to its leaves. In a tree, the xylem vessels reach all the way up the trunk and to the very tips of the branches.
The xylem vessels continue inside the leaves. The position of xylem vessels in a root. Xylem vessels are very tiny. The spots that you saw in the celery stalk each contain several xylem vessels. The diagrams show where the xylem vessels are in a root, a stem and a leaf. The dark blue areas show where xylem vessels are found. Xylem vessels have very strong, hard walls. This means that they help to support the plant, as well as transporting water and minerals.
The positions of xylem vessels in a stem. The wood in a tree trunk is made up of xylem vessels. If you are working at a wooden desk, you may be able to see the xylem vessels that make up the wood. The positions of xylem vessels in a leaf. In a leaf, the xylem vessels are inside the veins. This is a piece of wood seen with a powerful microscope. Each hole is the cut end of a xylem vessel.
Choose the correct word to match each description. You may use each word once, more than once or not at all. This gas is made by plants in photosynthesis. Plants get their water for photosynthesis from here. This green pigment absorbs energy from sunlight. This tissue in a leaf is where most photosynthesis takes place.
These tiny holes in a leaf allow gases to move in and out. The photograph shows the upper surfaces of leaves from two different plants. The leaves are both shown life-size.
Construct a table that you can use to compare the structure of the two leaves. Then complete your table to show at least five differences between the leaves. The diagram shows the apparatus he used. Food gives us pleasure. It also gives us the nutrients that we need to stay healthy. Different kinds of food contain different nutrients. These foods are good sources of protein. Protein, carbohydrate and fat The nutrients that we need to eat in the largest quantity are protein, carbohydrate and fat.
Protein is used for making new cells. Protein is also used for making many important chemicals in the body, such as enzymes see pages 28—29 and antibodies see page Cells can use protein to supply energy. Carbohydrate is used to provide energy. Starch and sugar are two kinds of carbohydrate. These foods are good sources of starch a type of carbohydrate.
Fat also provides energy. Fat can be stored in the body. Fat stores underneath the skin provide insulation. Fat is needed to make new cell membranes. Vitamins and minerals Vitamins and minerals are nutrients that we need in only very small quantities. They do not provide energy. There are many different kinds of vitamins and minerals that we need to eat.
Fruit and vegetables are a good source of some of them. There is more information about two vitamins and two minerals on page These foods contain a lot of fat. Fibre and water Fibre roughage helps to keep food moving easily through the digestive system. We get fibre from fresh fruit and vegetables, and also from foods made from whole seeds such as brown rice or wholemeal bread.
Water is sometimes considered to be a nutrient. List them all. Activity 2. You can find out if a food contains starch using iodine solution. If the iodine turns blue-black, there is starch in the food. Add a little water and stir or shake it well. Leave it for about 5 minutes. Add as many more rows as you need.
Food Colour with iodine solution Did it contain starch? Your diet should provide you with enough of each kind of nutrient. It should also give you the right amount of energy. Bread, pasta and rice contain a lot of starch and some protein.
Fruit and vegetables contain a lot of fibre and vitamins. A diet that provides all the different kinds of nutrients, and the right amount of energy, is called a balanced diet. Nutritional deficiencies If a person does not eat enough of a particular nutrient, their body may not be able to work properly. They may have a nutritional deficiency disease. For example, a child who does not have enough protein in her body may not be able to make enough new cells.
She will not grow properly. The table shows information about two vitamins and two minerals, and the deficiency diseases that develop if they are lacking in the diet. Nutrient Example Good sources vitamins vitamin C citrus fruits Dairy foods contain a lot of protein and fat.
Sweet things contain a lot of sugar. This photograph shows approximately how much of your diet should be made up of each of the five food groups. Function in the body helps to make strong skin vitamin D dairy products needed to make bones and teeth minerals iron red meat, dark green needed to make vegetables haemoglobin, which carries oxygen in the blood calcium dairy products, fish needed to make bones and teeth 20 2 Food and digestion Fish, meat, eggs, nuts and pulses contain a lot of protein.
Deficiency disease scurvy — the skin becomes weak, so sores develop rickets — the bones are weak, so the legs may become bent anaemia — the blood cannot carry enough oxygen, and the person feels very tired the bones and teeth become weak 2. Too much sugar can make your teeth decay. Too much fat in the diet can increase the risk of developing heart disease when you are older.
Eating too much fat and carbohydrate may mean that you take in more energy each day than you use. The body stores these extra nutrients as fat. Everyone needs some fat stores, but it is not good to have too much. Being seriously overweight can cause damage to joints, and increase the risk of developing heart disease and diabetes. What should I eat? These students are giving some good guidelines for eating a balanced diet. Eat plenty of fresh fruit and vegetables.
Eat a wide variety of foods, including something from each of the food groups in the photograph, each day. Question 1 The sentences below are reasons for the pieces of advice the students are giving. Match each reason with the piece of advice. It is fine to eat some of it, as long as you eat plenty of other kinds of foods as well.
The other end of the tube is called the anus. The diagram summarises what happens to the food that an animal eats, as it travels through this tube. This is called absorption. What happens inside the alimentary canal.
Absorption and digestion The food inside the alimentary canal can only reach your body cells if it can get out through the walls of the tube.
This process is called absorption. Protein, starch and fat are important nutrients. Each of these nutrients is made up of large molecules. A molecule is the tiniest particle of a substance that can exist. Molecules of protein, starch and fat are so big that they cannot get through the walls of the alimentary canal. So, in order to get these nutrients to your cells, the big molecules have to be broken down into much smaller ones. Then the small molecules can be absorbed.
This is what digestion is. Digestion is the breakdown of large molecules into small ones, so that they can be absorbed. It has tiny holes in it — much too small for you to see — that will let small molecules go through, but not big molecules. Moisten it with water. Rub it between your fingers until it opens up into a tube. When it is nearly full, use cotton to tie it very tightly around the top.
Add enough water to the beaker to cover the tubing. Leave it for about 15 or 20 minutes. Record your results. Visking tubing water cotton tied round one end knot tied in one end mixture of starch, sugar and water Questions A1 A2 A3 A4 Explain why it was important to tie both ends of the tubing very tightly. Explain why it was important to wash the outside of the tubing. Which nutrients — starch or sugar — were able to get out of the tubing?
Use what you know about starch molecules and sugar molecules to suggest an explanation for your results. A5 Imagine you have eaten a meal containing starch and sugar. Do both of these nutrients need to be digested inside your alimentary canal? Explain your answer. The digestive system is made up of the alimentary canal, plus the salivary glands, liver and pancreas. Can you work out which parts are shown? The human digestive system.
Questions 1 After it has been swallowed, food moves along through the space inside the alimentary canal. Write down, in order, the name of each part of the alimentary canal that food passes through as it travels from the mouth to the anus.
Saliva starts to break down starch to sugar. Oesophagus Food just passes through here without changing. Large intestine All the food that could not be digested and absorbed passes through here. A little more of the water in it is absorbed. The undigested food collects up and forms faeces. Stomach Hydrochloric acid kills micro-organisms in the food. Stomach juices begin to break down protein to amino acids. Liver The liver makes bile. The bile is stored in the gall bladder.
Bile flows into the small intestine, where it helps with fat digestion. Small intestine Juices from the pancreas finish breaking down starch, protein and fat to small molecules. These small molecules are then absorbed through the walls of the small intestine. Water, vitamins and minerals which are already made of very small particles are also absorbed. Pancreas The pancreas makes pancreatic juice. Pancreatic juice flows into the small intestine, where it helps to digest protein, starch and fat.
Absorption happens inside the small intestine and large intestine. Inside your mouth there are four different kinds of teeth — incisors, canines, premolars and molars. Incisors are chiselshaped, with a sharp edge. They are used for biting off small pieces of food so that you can take the food into your mouth.
Canines are more pointed than incisors. In humans, they are used in the same way as incisors. Molars are like premolars, but sometimes a bit bigger.
They are also used for crushing and grinding food. Premolars have broad surfaces with ridges on them. They are used for crushing and grinding food when you chew. The four kinds of human teeth.
What do dogs use their canine teeth for? The structure of a tooth The diagram shows what an incisor tooth looks like if it is cut in half. The diagram also shows the gum and jawbone.
Teeth are held in the jawbone by strong fibres. However, it can be dissolved by acids. If that happens, you may get a hole in your tooth. This can be painful when the hole reaches the pulp cavity, where there are nerve endings.
This means that drinking lots of acidic fizzy drinks like cola or lemonade can harm your teeth. This is because bacteria in your mouth break down food remains left on and between your teeth — especially sugary things.
The bacteria make acid when they break down the food remains. Fluoride helps to strengthen the enamel on your teeth. Your teacher may be able to provide these. Tie the other end around a small stone or weight. Pour the same depth of tap water into the other beaker. This brightly illustrated Coursebook for Stage 9 offers a comprehensive introduction to all topics covered in the syllabus.
Worked examples show students how to tackle different problems, and plenty of exercise questions prepare students for the different types of questions they will face in their Checkpoint exam. Coverage of the Problem Solving framework is integrated throughout the course, with questions relating to the Problem Solving framework statements highlighted in the Coursebook. Introduction; Acknowledgements; Unit 1. Integers, powers and roots; Unit 2.
Sequences and functions; Unit 3. Place value, ordering and rounding; Unit 4. Here are some powers of 5. Square numbers have square roots that are integers.
Write down these two numbers in full. What number is N? What number is M? What could her number be? It is between and Its square root is an integer.
What is the largest possible value of his number? I am thinking of a number. It is less than Its cube root is an integer. Find a possible value for her number. Use this fact to find: b a 3 e 3 I am thinking of a number. If so, describe it. Summary You should now know that: You can multiply or divide two integers. You can subtract a negative number by adding the corresponding positive number. You can find multiples of a number by multiplying by 1, 2, 3, etc.
Prime numbers have just two factors. You can write every positive integer as a product of prime factors. You can use the products of prime factors to find the lowest common factor and highest common multiple.
Positive integers have two square roots. Identify and use multiples and factors. Identify and use primes. Find common factors and highest common factors HCF. Find lowest common multiples LCM. Calculate squares, positive and negative square roots, cubes and cube roots. Use index notation for positive integer powers. Calculate accurately, choosing operations and mental or written methods appropriate to the numbers and context.
Each number is the product of the previous two numbers. If so, what are they? Write down as a number: a 1K b 2K c 4K. What mistake has he made? One of the numbers is Find a possible value of the other number. Cambridge Checkpoint Mathematics Coursebook 8 December 6, This brightly illustrated Coursebook for Stage 8 offers a comprehensive introduction to all topics covered in the syllabus.
Worked examples show students how to tackle different problems, and plenty of exercise questions prepare students for the different types of questions they will face in their Progression test. Coverage of the Problem Solving framework is integrated throughout the course, with questions relating to the Problem Solving framework statements highlighted in the Coursebook. This brightly illustrated Coursebook for Stage 7 offers a comprehensive introduction to all topics covered in the syllabus.
Worked examples show students how to tackle different problems, and plenty of exercise questions prepare students for the different types of question they will face in their exam. Coverage of the Problem Solving framework is integrated throughout the course, with questions relating to the framework statements highlighted in the Coursebook and Practice Book.
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