Download Marin Master Gardeners Farm Day 2014 Teacher Packet

 Marin Master Gardeners University of California Cooperative Extension Farm Day 2014 Teacher Packet Introduction: This teaching resource is designed for teachers whose students will visit our exhibits at the 2014 Farm Day. Marin Master Gardeners will have a two-­‐part exhibit about the parts of a flowering plant: Part 1. The Important Job Of A Flower is about flowers, how they produce the seeds and fruit to assure the survival of the species and how they provide us with the seeds and fruit we love to eat. Part 2. Roots, Stems And Leaves: Of What Use Are They? addresses the other basic parts of the plant, their purposes in supporting the plant and the food they provide for us. This packet provides a compilation of information from many sources to address the Part 1 of the exhibit and an introduction and recommended reading for the Part 2. Activities: One game is made up of a large chart of a plant and its parts and children can play by placing discs with words of the job done by a plant part or pictures of food we eat from a plant part on the associated part of the plant on the chart. There will also be paper hatbands with pipe-­‐cleaner antennae that the children can color and put on to represent pollinating bees or butterflies. Teaching Objective: To have the students understand both the botanical purpose of parts of a plant and the food those parts provide for us. Through this information, students will begin to look differently at their food and at plants and, perhaps, develop a greater interest in how remarkable plants are in their ability to not only provide us food, but, primarily to get the food and water they need to live and grow, attract insects birds and other animals to help them get the pollen they need to develop seeds, and attract animals and humans to their fruit to help disseminate and sow seeds for future plants. Who knows, it might be the beginning of a career interest in botany or another science . . . or in the food industry. Part 1. The Important Job of a Flower Key Terms: Anthers – The bright yellow sacs that produce and contain the pollen grains. Filament – The thin stalk that supports the anther. Nectar – A sugary liquid, usually at the base of a flower, which attracts pollinators to go into a flower to collect food for itself and its young. Ovary – The enlarged base of the pistil where ovules are produced. After fertilization, the ovary becomes a fruit. Ovules – The eggs, contained in the ovary, which, when fertilized by the pollen, become seeds. Petals – The colorful, thin structures that surround the reproductive parts of the flower. They not only attract pollinators, but also protect the pistil and stamen. They may also produce a scent. Pistil – The part of a flower, consisting of the stigma, style and Ovary. Pollen grains – The powdery particles that contain the cells needed to fertilize the ovules. Pollen is also a nutritious, protein-­‐rich food for bees. Pollination – The act of transferring pollen from the anther of one plant to the stigma of another plant. The pollen may be carried by the wind or water, but is usually transported by a go-­‐between insect, bird or bat. Seeds – Produced when the ovule of one flower is fertilized by pollen from another flower. A seed contains all the genetic information needed to make a new plant. Only flowers from the same species of plant can produce seeds. Sepals – Commonly green, leaf-­‐like structures that protect the bud prior to opening. Stamen – The part of a flower, consisting of anther and filament. Stigma – The sticky surface where the pollen lands and germinates. Style -­‐ The tube-­‐like structure between the stigma and ovary, through which the pollen travels to fertilize the ovules. Why Focus on Flowers? Most of our food comes from living things – some from plants and some from animals, but mostly from plants. Flowering plants provide most of our food. Scientists at Kew Gardens, which is a global center for plant classification, estimates that there were 352,000 species of flowering plants in 2008 and likely more to be identified. While we often use flowers to decorate our homes, plants use flowers to produce the seeds to reproduce and ensure the survival of the species. Flowers are the reproductive part of the plant. They produce the male and female cells. They also protect the growing seeds and ultimately produce fruit. Parts of a Flower Drawing of a flower’s parts from: http://www.amnh.org/learn/biodiversity_counts/ident_help/Parts_Plants/p
arts_of_flower.htm A typical flower has four parts, arranged in rings inside each other. The flower parts are gathered together on a receptacle, which is the enlarged top of the stem. In the center are one or more pistils surrounded by a ring of stamens, then a ring of petals, and then a ring of sepals. The sepals’ primary purpose is to enclose and protect the unopened bud. The petals protect the tender stamens and pistils, but their most important role is to attract various pollinators and provide them a place to land that will lead them to the pollen and nectar. Stamens are the male parts of flowers. They consist of thin stalks called filaments with little sacs at the tips called anthers. The anthers produce, store, and release pollen grains. Pistils are the female parts, made up of three sections. The stigma, at the top, is sticky to catch and hold pollen. The ovary at the base contains ovules (future seeds). Between the stigma and ovary is a style, through which the pollen travels from the stigma to the ovary and to the ovules. In some plants, the pistils and stamens are in one flower. Most plants are arranged that way. In some plants, however, the pistils are in one flower and the stamens in another. Even if pistils and stamens are in one flower, in order for pollination to produce a seed from an ovule, the pollen must come from one plant and reach the ovule of another plant of the same species. How Does Pollination Work? (Much of the information from the next two sections is from the “Kids Splash” article, identified below. That article also had some good illustrations that you might want to see.) How does the pollen from one flower get to the ovules of another flower? Unlike animals, plants can’t walk or fly over to another plant to shake some pollen from its anther onto the stigma of another plant’s flower. That’s why they have colorful and/or scented flowers to attract pollinators to do the work for them. Pollinators can be bees, flies, beetles, moths, hummingbirds, bats and other animals that visit flowers. They regularly travel from flower to flower to gather the nectar and pollen to feed themselves or their young. The plants produce nectar just to reward the pollinators for stopping by. The colors and scents of flowers attract the attention of pollinators, letting them know where to land for their supply of nectar and pollen. When a pollinator goes into a flower to collect nectar or pollen, tiny grains of pollen from the anthers of the flower stick to their bodies. When the pollinator visits another flower of the same species, some of this pollen brushes onto the sticky stigma. The pollen then travels from the stigma, down the style, to the ovary, where the pollen can fertilize the ovules. When an ovule is fertilized, the genes from the pollen combine with the genes of the ovule and a seed is made. The Job of a Flower The job of a flower is to help its pollinator put pollen exactly in the right place at the right time to make a seed. When a plant’s flower succeeds at this, the plant gets to pass the secret for this success to the next generation, through the genetic code in its seeds. Only strong plants survive and keep making seeds. They have succeeded in adapting to every habitat on our planet. Although the pollination of a flower may appear to happen by accident, plants and pollinators have been practicing for millions of years to make sure that this “accident” happens. Often, a plant and pollinator co-­‐evolve (evolve together), adapting to changes in each other to improve their own survival. A plant species may depend on a single species of pollinator to make its seeds. Many pollinators rely on one plant species to provide all the food for their young. The complex relationship between solitary bees and certain plants is a good example of this co-­‐
evolution. A minority of plants relies on wind, rather than a pollinator, to get the pollen to the stigma. The petals and sepals of these plants are small and inconspicuous, or often missing altogether. How Are Fruits Made? When petals and stamens have served their purpose, they nearly always dry up and fall off. Often the sepals fall off, too. The pistil, however, is just beginning its major role. The pollen germinates on the stigma and travels down the style and into the ovary. There they fertilize the ovule, which begins to grow into a seed and the ovary begins to grow into a fruit. If there is no fertilization, no fruit can develop. Once the ovule is fertilized, the size of the developing fruit increases rapidly. The plant needs to provide lots of food and energy for growing fruit. The plant uses its ability to make food by photosynthesis, which occurs in the leaves. The green color in the leaves is a substance called chlorophyll. To make food, the leaves need their chlorophyll, water and minerals obtained from the soil, and sunshine and air (specifically, carbon dioxide from the air). The amount of food and water available greatly affect fruit size and quality. There must be a sufficient number of leaves to produce enough nutrition for the developing fruit, while keeping the rest of the plant healthy. For example, it has been estimated that a minimum of 40 leaves in sunlight are needed to support the growth of one apple on a mature tree. Adequate soil moisture must be available too, or the fruit may be small and poorly developed, or the fruit may drop from the tree before it can mature. Fruit drop during the early stages of development may be normal for a plant and serve to adjust the fruit load to a level that the plant can adequately support. Types of Fruits: Fruits are all the ripened ovary of a plant containing seeds, but there are many types, because the plants they come from have many different genetic codes determining whether they will be large or small, dry or juicy, have many seeds or only one or a few. Some fruits have one big, hard seed inside them, called a pit. Cherries, peaches and avocados are some examples of fruits with pits. Some fruits have rubbery skin, like an orange, or thin skin, like a grape. Some even have their seeds on the outside, like a strawberry, instead of on the inside, like most fruit. In some fruits a large portion of the fruit is edible and you don’t have to worry much to avoid the seeds, like an apple. Others, like pomegranates, have just a small edible amount that is juicy and tasty, but the seeds are hard to avoid. Sometimes we don’t want to avoid the seeds because that is the part that tastes good and provides good nutrition. Many people like to eat pumpkin seeds, usually roasted, and, while some people may not know it, peas and lima beans are seeds, too, and they are good and nutritious. Some of the fruits we eat we call “vegetables” and not “fruit.” While this habit is usually because we think of fruit as sweet or tangy and not something we might put on our plate for dinner, squash, tomatoes, peppers, peas and any food we eat that contains seeds is a fruit. Fruits and vegetables are parts of plants. A vegetable can be the leaf, such as spinach; the stem, such as asparagus; the root, such as carrot; or even the flower, such as broccoli. Vegetables do not contain seeds. A few fruits look more like seeds than fruits. This is especially true of the kernels of cereals like corn, rice, wheat, oats, and barley. Each kernel consists almost entirely of a single seed. The outer part of the fruit is so thin and sticks to the seed so well that you can hardly tell where the fruit ends and the seed begins. One cereal grain – wheat – supplies people all over the world with more food than any other plant or animal product. Not all fruits are edible for humans, but may be edible for other animals. The Job of Fruits: The purpose of fruit is not necessarily to be edible but is produced by plants to contain the seeds for the production of new plants. The fruit protects the seeds until they can locate a good place to find the sun, water, air and nutrients for the seeds to germinate and grow into new plants. Fruit does help to disperse seeds to places where they might grow well. They are often beautiful to look at as well as good tasting. Animals may eat the whole fruit, but discharge the seeds through their poop or eat part of the fruit and drop the rest. Animals, like squirrels, may hide fruits and seeds to store them for later eating and if they forget or wait too long to come back, the seeds may grow into plants. Works used in the preparation of Part 1 of this packet: Dowden, Anne Ophelia. (1984) From Flower To Fruit. Thomas Y. Crowell, New York. Pp 5 – 17, 36. Rahn, Joan Elma. (1974) Grocery Store Botany. Atheneum, New York. Richards, Jean. (2002) A Suitcase For Seeds. The Millbrook Press, Brookfield, Connecticut. University of California, Agriculture and Natural Resources, Publication 3382. (2009) California Master Gardener Handbook, Dennis R. Pittenger, editor. P 23. Kids Splash, Mather Field Vernal Pools, Flower Facts (Go to the link below and click on # 32, “Why Do Plants Have Flowers,” near the bottom of the page. More direct sites do not work.) http://www.internet4classrooms.com/science_elem_plants.htm “Parts of a flower” drawing is from the American Museum of Natural History site: http://www.amnh.org/learn/biodiversity_counts/ident_help/Parts_Plants/parts_of
_flower.htm Kew Science and Conservation website http://www.kew.org/science-­‐
conservation/running-­‐repairs/biodiversity-­‐conservation/flowering-­‐
plants/index.htm Part 2. Roots, Stems and Leaves: Of What Use are They? Flowers produce the seeds and fruit important to the survival of the species into the future. Through the production of seeds and fruit, flowers also produce most of the food people eat. However, plants could not live without the work provided by the other basic parts of the plant; the roots, stems and leaves are essential to a plant’s survival, providing stability, storing food and producing or taking in the nutrition, water, air and light the plant needs to grow. These other parts of the plant also provide us with the vegetables we eat: food that is nutritionally important to our diet. We recommend you go to the two following useful resources for teaching this subject to your students. Both have appropriate elementary-­‐level information on plant science and ideas for engaging children in the materials: University of Illinois Extension, Teacher’s Guide. The Great Plant Escape, In Search of Green Life. http://urbanext.illinois.edu/gpe/case1/c1facts2a.html Rahn, Joan Elma. (1974) Grocery Store Botany. Antheneum, New York