Plants and Photosynthesis

Transcription

1 Plants and Photosynthesis Name: Look for more resources at 1

2 Date: Let s revise the parts of the plant. Look at the names of the parts carefully. Then turn to the next page and fill in the parts of the plant. Try not to peep at this page. When you have filled it all in look back and mark your own work. Look for more resources at 2

3 Date: Look for more resources at 3

4 Match the parts of the plant with the work they do their FUNCTION. Draw a line from the part of the plant to the function. Produces food for the plant because it contains chlorophyll Causes the plant to grow in length by producing a shoot at the top of the plant. Holds the leaf out in a good position to trap sunlight This part of the plant absorbs carbon dioxide from the air. This grows into a side shoot and often produces flowers and more leaves. This is an area of cells that are actively growing This root grows sideways and makes the plant stand firmly in the ground. It gives it extra stability in the ground. There are many of them and they increase the quantity of water that can be absorbed by the plant. The root hairs absorb water and mineral salts from the soil. This root grows deep into the ground and anchors the plant firmly in the ground so that it does not blow over. Look for more resources at 4

5 Read the functions of the plant on the previous page and then answer the following questions. Put a circle around the correct answer 1. Which part of the plant contains chlorophyll? flower leaf root 2. Which part of the plant anchors it firmly into the soil so that it cannot blow over? stem roots leaves 3. Which part of the plant increases the surface area that can absorb water for the plant? roots stems flowers 4. What do we call the cells that are actively growing on the stem? nodes internodes cells 5. Which part holds the leaf in a good position for light? stem petiole leaf blade 6. Which part of the plant produces side shoots? root system stem leaves C H L O R O P H Y L L A R A S A R G A R E L A R E T A L G B H X Y T I T N A U Q D F T H F S R I S U N L I G H T H A E S A O J L G H R D B F J E G K R J E R D L D S G F L G D S D L A G L P M A P R I M A R Y K A O L D O T E R J F A D D R F C D K N R I I T Y S R L K E A I S A J O R T O S A K H M E S P K G L H F S E N Y H R J D J A H A H C R A R P T S D S O F R H F J N K F G D R L N L N H S G S T A B I L I T Y F J I Find these words in the word search to help you to learn to spell them. CHLOROPHYLL NODE INTERNODE AXILLARY LATERAL PRIMARY PETIOLE BLADE LEAF ANCHOR ABSORPTION STABILITY APICAL SUNLIGHT SYSTEM QUANTITY Look for more resources at 5

6 Here s a bit more revision. Do you remember all the parts of the flower? Take a good look at the names of the parts of the flower. Do you remember these names? After having a good look, cover this picture and then fill in the names on the picture below. Colour the picture in. When you have filled in all the names look back and check your answers and the spellings. Look for more resources at 6

7 How do plants make food? Plants make their own food in their leaves. They do not get food from the soil or from water. The leaves can make food for the plant because they are green. The green chemical in a leaf is called CHLOROPHYLL. Plants make food in a process called PHOTOSYNTHESIS. Photosynthesis can take place slowly or quickly. It depends on the temperature of the air. Photosynthesis takes place more quickly when it is warm. To make food plants need these things: Here are the 4 things needed for photosynthesis to take place: sunlight water carbon dioxide chlorophyll Now see if you can answer these questions with TRUE or FALSE. 1. Plants get food from the soil. 2. Plants make food in their green leaves. 3. Water gives the plant the food it needs. 4. It is the green chemical in leaves that helps make the food. 5. To make food a plant needs oxygen. 6. Chlorophyll is green. 7. Photosynthesis makes chlorophyll. 8. Photosynthesis is when the plants makes food in its leaves. 9. A plant needs water to make food. 10 The plant gets food from the sun. 11 Sunlight is needed for photosynthesis. 12 The speed of photosynthesis is always the same in a leaf. 13 The speed of photosynthesis depends on the temperature. 14 It needs to be warm for photosynthesis to take place quickly. Look for more resources at 7

8 carbon dioxide + water sunlight chlorophyll glucose + oxygen What does this mean? When a plant makes food it takes the water and the carbon dioxide and joins them together with the sun s energy. To do this it needs chlorophyll. A chemical reaction takes place inside the chloroplasts (the little structures containing chlorophyll ). Think of a CHLOROPLAST as a factory. In the pictures below fill in the names of what is going on. A chemical reaction takes place inside the chloroplast because of the chlorophyll. Then food is made for the plant. This food is called GLUCOSE. There is a waste product of photosynthesis. This waste product is OXYGEN. During photosynthesis the plants gives off oxygen That is why green plants are needed on the earth to make new oxygen for us to breathe in. The main product made is called. What is this waste that is coming out? The first raw material needed to make food is The green chemical inside the chloroplast is called. The other raw material that is needed to make food is Look for more resources at 8

9 Now test yourself to see how much you have remembered. When you have finished, check your answers by turning back and finding the answers on the worksheets that you have already completed. In the box write out the word formula that shows the process of photosynthesis. + + Now answer these questions based on this word formula. 1. What do we call the green chemical needed for photosynthesis? 2. Which gas is needed for photosynthesis? 3. What 2 other raw materials are needed to make food? 4. What is the main product of photosynthesis? 5. What is the waste product of photosynthesis? Now check your answers. Correct any that you got wrong. WHAT DOES THE WORD PHOTOSYNTHESIS MEAN? This long word comes from 2 words: PHOTO meaning LIGHT SYNTHESIS - meaning TO MAKE So the word means - making something from light. That something is food in the form of glucose. Look for more resources at 9

10 More facts about PHOTOSYNTHESIS carbon dioxide + water sunlight chlorophyll glucose + oxygen 1. How does the carbon dioxide enter the leaf? The leaf has tiny holes on its surface. These holes are called STOMATA. One of these holes is called a STOMA. Most of the stomata are on the under surface of the leaf. There are a few stomata on the top surface. The carbon dioxide DIFFUSES into the stomata. Stomata on the surface of a leaf. (Highly magnified) BUT HOW DO ALL THESE THINGS GET INTO THE LEAF? Fill in the missing words: A leaf has tiny on its. These holes are called. One of these holes is called a. Most of the stomata are on the surface of the leaf. There are a few on the top surface of the. The carbon diffuses into the. Write these words out 3x each: photosynthesis stomata chlorophyll dioxide Why do you think there are more stomata on the under surface of the leaf? Look for more resources at 10

11 2. How does the SUNLIGHT enter the leaf? The inside of the leaf is designed to trap sunlight. The top layer of the leaf is covered with a clear waxy layer. This lets the sunlight in but stops the water from escaping from the surface of the leaf. The cells under the waxy layer have only a few chloroplasts and let the sunlight through. The long cells under this layer have the chloroplasts arranged on the sides so the sunlight can get down deep into the leaf. The petiole holds the leaf blade out in a way to catch Match up the 2 halves of a sentence by joining them with a coloured pencil The inside of a leaf The top layer of the leaf This waxy layer allows The waxy layer also The cells under the waxy layer The long cells in the leaf Because the chloroplasts are down the side of the cells it means that The petiole is the leaf stalk and it holds the leaf blade in a good position to catch sunlight. only have a few chloroplasts so they are quite transparent. have the chloroplasts arranged down the sides of the cells. is well designed to trap sunlight. the sunlight can enter deep into the cells of the leaf. is covered with a clear, waxy layer. stops water from leaving the cells inside the leaf. the sunlight to enter the leaf. Watch The process of photosynthesis at Look for more resources at 11

12 What does the plant do with all the food it makes? What happens to all the food you eat? 1. It is used for energy for all your activities. 2. It is used for cell growth if you are a growing adolescent. 3. Any excess is stored as FAT! (specially on our bellies and hips SO... It is exactly the same for a plant! The plant uses the glucose for: 1. Energy for all the processes in the plant such as respiration, photosynthesis etc. 2. Growth for new shoots, fruits and flowers. 3. Storage extra glucose that is not immediately is stored not as fat but as starch. It could be stored in the leaves, stem or root. One of our main food sources is the stored starch of plants eg potatoes, carrots, turnips etc. It is also stored in the fruit of a plant eg apples, oranges etc. They also store the starch in their leaves for when it is dark and the plant cannot photosynthesise because there is no sunlight. Read the fact sheet above then do this activity. 1. Name 2 processes that a plant needs energy for? and. 2. What growth is taking place that the plant needs energy for? 3. In what form does the plant store its extra glucose? 4. Where is this starch stored? 5. Why are some plants so important to man? 6. Why do plants store starch in their leaves? Look for more resources at 12

13 A small, young plant. What do we mean by BIOMASS? When a plant photosynthesises it produces a lot of glucose. It grows and gets larger. Its mass increases. We call this an increase in BIOMASS. The plant has grown bigger and bigger (increased its biomass) using carbon dioxide, water and the sun s energy together with chlorophyll. The same plant 5 weeks later with a great increase in BIOMASS Name the 4 things that a plant needs to be able to increase its BIOMASS Look at the list above. Three of these things will affect how much food a plant can make. They are: 1. Sunlight 2. Water 3. Carbon dioxide. TEMPERATURE also affects the rate of photosynthesis. Plants can t make food (photosynthesise) if the temperature is too hot and they also can t if the temperature is too cold. They like the temperature to be just right not too hot and not too cold. Look for more resources at 13

14 Watch how plants respond to a light source at 91s What happens if you increase the light that the plant gets? Strong light source Lots of bubbles of oxygen Weak light source Fewer bubbles of oxygen What is happening here? What effect is the light having? Choose words from this box to fill in the spaces below. You may use some of the words more than once. oxygen photosynthesis lots fewer light From the drawings above we can see that if you give a plant more then will be faster. When there is a strong light close to the plant we can see of bubbles of. When the light source is weaker or further away then we can see bubbles of. When plants photosynthesise they give off as a by product. In the When is photosynthesis strongest? or at Put a circle around the sun (day) or the moon (night). Explain why you made this choice. Look for more resources at 14

15 Use the pictures in this diagram to explain the process of photosynthesis in your own words. Look for more resources at 15

16 The structure of a leaf and its role in photosynthesis. Why are leaves green? Leaves are green because they contain a PIGMENT called CHLOROPHYLL. The chlorophyll is found in small bodies called CHLOROPLASTS. Chlorophyll can catch the energy of the sun. The chloroplasts are found in the palisade mesophyll layer of the leaf. The chloroplasts are arranged down the sides of these cells so that the sunlight can get to all the chloroplasts. This makes sure that the maximum amount of light is absorbed by the chlorophyll inside the chloroplasts. Complete these facts: 1. Leaves are green because 2. Chlorophyll is found 3. Chlorophyll can catch 4. Chloroplasts are found 5. The arrangement of the chloroplasts in the cells makes sure that Look for more resources at 16

17 More facts about leaves. The veins transport water around the leaf blade The leaf is very thin so the light can reach all the cells inside the leaf The leaf is very wide so it can trap a lot of light. The petiole or leaf stalk holds the leaf in a good position to catch the light. Use each of the keywords below to write a fact about the leaf. veins thin wide leaf stalk Look for more resources at 17

18 How a leaf is adapted to help photosynthesis happen. First look carefully at the previous diagram of the leaf. Then fill in the labels on this diagram. Check and correct any errors. Photosynthesis can happen in a leaf because of the way that the cells are arranged inside the leaf. Each different type of tissue has a very important function. Here is a page of important facts to learn! UPPER EPIDERMIS On top of the epidermis is the CUTICLE. The cuticle is WAXY and stops water from evaporating out of the leaf. The epidermis is clear and this lets the light straight through to the cells lower down. PALISADE PARENCHYMA This is where photosynthesis takes place because they contain green bodies called CHLOROPLASTS. The chloroplasts are arranged down the sides of the cells so that the light can shine down the middle of the cells and maximise photosynthesis. The palisade cells are long and thin and packed tightly together. They are near the top of the leaf where they can get the maximum amount of sunlight. Chloroplasts contain CHLOROPHYLL. The chlorophyll can absorb the energy from the sun. THE SPONGY MESOPHYLL LAYER These cells are below the palisade cells and they also contain chloroplasts. The cells are loosely packed and the airspaces allows carbon dioxide to get to all the mesophyll cells. LOWER EPIDERMIS The cells contain small holes. These are the STOMATA. The stomata allow carbon dioxide into the leaf and oxygen out of the leaf. Look for more resources at 18

19 How a leaf is adapted to help photosynthesis happen. Read these facts about the leaf blade. Then answer the questions that follow. The shape of the leaf The leaf blade is BROAD and FLAT. This gives a large surface area for gases to enter and leave the leaf. The leaf blade is very thin This means that the carbon dioxide can dissolve very rapidly though the leaf blade. Moist internal surfaces The gasses can dissolve easily into the cells. Arrangement of the chloroplasts in the leaf The chloroplasts are arranged down the sides of the cells and allow the light to pass through their centre. This allows maximum light to enter and pass over the chloroplasts. The waxy cuticle on the upper surface This waxy layer prevents the water in the leaf from evaporating. Some plants have hairs on their upper surface to further prevent water loss. The stomata are on the lower surface of the leaf The stomata are open during the day. CO2 can enter the leaf but water can also diffuse out. Being on the lower surface prevents too much water escaping as they are not in direct contact with the sun s rays. Stomata are microscopic pores found on the lower epidermis of leaves. There are guard cells on either side of the opening. Each guard cell contains chloroplasts. The guard cells either open or close the opening of the stomata. Look for more resources at 19

20 Join the facts together with a coloured pencil. Each fact on the left column matches a fact in the right side column. The leaf blade is broad and flat The leaf blade is very thin The internal surfaces of the leaf are very moist The chloroplasts are arranged down the sides of the cells. There is a waxy cuticle on the upper epidermis of the leaf. Some plants have hairs on their upper surface. The chloroplasts are arranged down the sides of the cells The stomata are on the lower surface of the leaf stoma on leaf surface This means that the gasses can dissolve very rapidly though the leaf blade. This prevents the water in the leaf from evaporating This allows the light to pass through their centre and give maximum light to the chloroplasts. Being on the lower surface prevents too much water escaping as they are not in direct contact with the sun s rays. This allows the light to pass through their centre. This allows maximum light to enter and pass over the chloroplasts. This gives a large surface area for gases to enter and leave the leaf. This prevents excessive loss of water in hot, dry climates like the desert. This means that the carbon dioxide can dissolve very rapidly though the leaf blade. Look for more resources at 20

21 What do we mean by BIOMASS? 1. What does a plant produce when it photosynthesises? 2. What happens to the plant when there is an increase in biomass? 3. What do we call the green chemical in leaves? 4. What 3 other things need to be present for photosynthesis to take place? Name the 4 things that a plant needs to increase its biomass Name 4 factors (things) that can make the rate of photosynthesis faster or slower Look for more resources at 21