Flowering Plants. by Lynn Durrant

Transcription

1 Flowering Plants by Lynn Durrant 1

2 10 tips for learning success Be independent and responsible for your own learning. Work collaboratively in pairs or groups. Use different strategies to help you understand scientific information. Share information to help you and others understand scientific knowledge better. Use different kinds of materials such as authentic texts and multimedia. Do activities that require thinking and problem solving. Draw conclusions from a scientific experiment. Provide scientific knowledge related to flowering plants. Assess your own work and that of others. Provide suggestions on how to improve. 2

3 1 Read the following texts. What is a flowering plant? All flowering plants generally have four physical features in common: roots, a stem, leaves and flowers. The roots anchor the plant to the ground and collect water and minerals from the soil. The stem, which is the central part of the plant, carries the water and minerals around it and supports the leaves and flowers. The leaves absorb sunlight and carbon dioxide which the plant uses to make food for itself. The flowers contain the male and female reproductive organs needed to reproduce. The flower part of a flowering plant makes the seeds. The main parts of a flower are the carpels and stamens. These parts are often found in the centre of the flower. There are egg cells in the carpel and pollen cells in the stamen. All flowers have four basic parts: sepals, petals, carpels and stamen. Different flowers have different numbers. 3

4 Pollination by insects Bees can help flowers make seeds. Bees look for pollen and sweet juice. Every flower has pollen, although some flowers don't have sweet juice. The bee's first job is to transport the pollen from the male anther of one flower to the female stigma of another flower. An anther is the male part of a flower that has pollen grains on it. A stigma is the female part of a flower that receives the pollen. When the bee lands on another flower, some pollen falls onto the stigma. Most flowers use this pollen to make seeds. Other flowers use their own pollen to make seeds. Each tiny pollen grain grows into a long tube. These are called pollen tubes. They grow until they come to the ovary. The ovary is the section of a flower where the pollen tubes meet. When a male gamete (reproductive cell) from the pollen tube joins the egg from the ovary, a seed is created. 4

5 Germination Germination is when the seed begins to grow. The root appears first and grows downwards into the ground. Then the stem appears and grows upwards out of the ground and towards the sun. Germination is really the beginning of life for a fertilised seed. For germination to occur, the seed has to receive the right amount of air, water and heat. 5

6 1 Recalling What can you remember? a. How many different parts of a flowering plant can you name? b. Which insect helps pollinate flowering plants? c. Which part of the plant supports the plant? d. Where does a bee go after it has taken pollen from a flower? Draw the following parts of a plant and label them. A petal, a leaf, pollen tube, root, stem. 2 Understanding What do you understand? Answer the questions. a. How does a plant obtain food? b. Why do plant roots grow downwards into the ground? c. Why does an anther have pollen grains on it? d. What happens to a seed when it doesn t have water or sun? 6

7 3 Analysing What do you think? Watch the video on the life cycle of a flowering plant. Then answer the questions below. a. What would happen to flowering plants if all the bees died? b. Why do most flowering plants that are pollinated by insects have large flowers that smell nice? Give two reasons. c. Why is it important for flowers that are pollinated by the wind to have large stamens and small petals? d. What would happen if flowers did not bloom anymore? The Thinking Lab Science, Flowering Plants, Cambridge University Press 2013 Revision The Thinking Lab Science, Flowering Plants, Cambridge University Press

8 Extension You are going to watch a video about growing roses. The man in the video is an expert rose grower and wants to produce a new kind of rose with a new combination of colours. Put the sentences below in the correct order to predict the process he will use. a. He needs to be patient and wait for new seeds to develop so he can plant them. b. He removes the sepals and petals from the first rose and then cuts the stamens and puts them in a little dish. c. He removes the sepals, petals, stamens and corolla from the second rose. d. He uses a small paintbrush to place the dried grains of pollen from the first rose on the top of the carpel of the second rose to pollinate it. e. He puts a top over the pollinated carpel to protect it. f. After that, he leaves the stamens from the first rose to dry in the shade. Now watch the video and correct your answers. The Thinking Lab Science, Flowering Plants, Cambridge University Press

9 Project The Thinking Lab Science, Flowering Plants, Cambridge University Press

10 The Thinking Lab Science, Flowering Plants, Cambridge University Press

11 The Thinking Lab Science, Flowering Plants, Cambridge University Press

12 The Thinking Lab Science, Flowering Plants, Cambridge University Press

13 Assessment Tools RUBRIC FOR FLOWERING PLANTS READING Recalling information Understanding information Applying information You can easily recall the You can easily understand the You can easily apply the You can recall most of the You can understand most of the You can apply most of the You can recall some of the You can understand some of the You can apply some of the You can recall very little or none of the You can understand very little or none of the information in You can apply very little or none of the PRESENTATION Preparation Speaks Clearly Stays on Topic You have carried out a complete preparation and have rehearsed. You speak clearly all the time and no words are mispronounced. You follow the topic all of the time. (100%) You have carried out a good preparation but a couple more rehearsals might have been needed. You speak clearly most of the time but one or two words are mispronounced. You follow the topic most of the time. (90%) You have carried out a fair preparation but lack of rehearsal is clear. You speak clearly most of the time but a few words are mispronounced. You follow the topic some of the time. (75%) You have carried out very little preparation and a lack of rehearsal is clear. You don t speak clearly and what you say is not understandable or more than a few words are mispronounced. You don t follow the topic and it s difficult to follow. 13

14 PROJECT Organisation You organised your work well. You organised a lot of your work. You organised some of your work. You put little effort into organising your work. Group Cooperation Research You took on full responsibility for your role and worked well with the others in your group. You were able to complete all the research. You took on most of the responsibility for your role and worked fairly well with the others in your group. You were able to complete most of the research. You took on some responsibility for your role and worked with the others in your group. You were able to complete some of the research. You took on very little responsibility for your role and found it difficult to work with others in your group. You weren t able to complete much of the research. Conclusions Poster You were able to reach clear conclusions based on research. The poster was a very good representation of the project. You were able to reach fairly clear conclusions based on research. The poster was a good representation of the project. You were able to reach some conclusions based on research. The poster was a fair good representation of the project. You were able to reach few conclusions based on research. The poster wasn t a very good representation of the project. Personal Portfolio Identify and write your own profile in every category. How can you improve your progress? 14

15 Checklist In this unit you have Worked independently and agreed to be responsible for your own learning. Worked collaboratively in pairs or groups. Used different strategies to help you understand scientific information. Shared information to help you and others understand scientific knowledge better. Used appropriate language and vocabulary to carry out and explain the findings from your research Explored a variety of authentic texts and multimedia. Carried out activities that are challenging and require thinking. Applied your knowledge of scientific information to a specific situation. Provided information and made a hypothesis based on your knowledge of flowering plants and observation of flowers. Taken greater responsibility for learning by assessing your own work and that of others. 15

16 Video scripts The life cycle of a flowering plant, page 7 Plants are living things. In order to grow they need water, minerals, air and sunlight. Some plants need flowers to reproduce. Flowers contain the genetic code for the new plant. Flowers have male and female reproductive organs in order to reproduce. Pollen is produced by the stamen, the male reproductive organ. The female reproductive organ, the pistil or the carpel, contains ovules. Pollination is the transfer of pollen to the ovule. There are different methods of pollination: by insects or by the air. By insects: flowers have large, colourful petals and nectar to attract insects. By the air: flowers have small petals and long stamens. Pine trees or oak trees are examples of plants that pollinate by the air. The life cycle of flowering plants has different stages. During the fertilisation process, the pollen and the ovule fuse together to produce a seed. This seed will grow into a fruit. A fruit contains one or more seeds. The fruits carry the seeds far from their parent plant. Seeds can be dispersed in the following ways: Dispersal of seeds by animals Dispersal of seeds by humans Dispersal of seeds by the wind Dispersal of seeds by explosion Dispersal of seeds by water Seeds germinate: a new plant starts to grow from a seed. Then the cycle begins again when flowers bloom in flowering plants and are ready to reproduce. Growing roses, page 8 Roses are perfect flowering plants. They have male and female reproductive organs. If we want to produce a new variety of rose, we need to cross-pollinate them. First, we select one of the roses we want to cross-pollinate. We need the pollen (the male reproductive grains), which is found in the anther. We carefully take off the sepals and petals from the rose. Then we use scissors to cut off the stamens and put them in a little dish. We leave the stamens to dry in the shade. After three days, the grains of pollen are free from the anther and are ready to pollinate another rose. Then we look for the second rose that we want to cross-pollinate with the pollen of the first rose. This time we need the female reproductive structure: the carpel. The petals of the rose we select must be closed and the rose must have a strong calyx. We carefully take off the sepals and petals as before. We must be careful not to fold its peduncle. Then we cut off all the flower stamens and we throw them away because we don t want to use them to pollinate this flower. Now we are ready to make the cross-pollination. Using a small paintbrush, we place the grains of pollen from the first rose on the top of the carpel of the second rose. Finally, we put a top over the carpel to protect the pollination from the wind, bees or other insects. The best time to do this is between May and July. By October the calyx of the rose should be bigger. The new seeds to plant are inside the calyx. We have created a new variety of rose but we need to be patient to see the results. 16

17 Acknowledgements Maldonado, N.; Bergadà, R.; Carrillo, N.; Jové, L.; Olivares, P. The Thinking Lab Science, Flowering Plants, Cambridge University Press