Plant Structures and Reproduction

Transcription

1 Plant Structures and Reproduction Lesson created by: Taylor Nyberg Date of lesson: TBD Description of the class: 9 th grade Biology Length of lesson: minutes Source of the lesson: TrumanHoltzclaw/index.php TEKS addressed: Biology (10) Science concepts. The student knows that, at all levels of nature, living systems are found within other living systems, each with its own boundary and limits. The student is expected to: (C) analyze and identify characteristics of plant systems and subsystems. (12) Science concepts. The student knows that interdependence and interactions occur within an ecosystem. The student is expected to: (C) compare variations, tolerances, and adaptations of plants and animals in different biomes; (13) Science concepts. The student knows the significance of plants in the environment. The student is expected to: (A) evaluate the significance of structural and physiological adaptations of plants to their environments; (B) survey and identify methods of reproduction, growth, and development of various types of plants. I. Overview: Students will first be given the materials to set up a long term experiment with Duck weed. Through observations over 1-2 weeks time the students will then chart the Duck weed s population growth. Some experimental variables that the students will determine in their groups will be: various colors of light, amount of fertilizer, water and space. During this time the students will be learning about plant structures, needs for growth, and reproductive pathways. II. Objectives: Students will be able to: 1. Describe various methods of reproduction for different types of plants. 2. Identify distinguishing features and needs of plants. 3. Create a unique experiment to be tested, collect data, and formulate conclusions based on that data using graphs. III. Resources, materials and supplies: 1

2 Duckweed Liquid fertilizer Plastic cups Pondwater Soil Water source Window or light source that can be set to a timer Large poster sized post-it paper (for graphing at the end) IV. Advanced Preparation: Have fresh Duckweed that the students can start with and make sure a significant light source can be accessed daily. V. Supplementary worksheets, materials and handouts: Lab sheet VI. Safety Considerations: Use care when dealing with liquid fertilizer not to ingest or get it in your eyes. 2

3 ENGAGEMENT Time: 5 minutes Potential Misconceptions Song about living things: How does the song define something as living? How does that apply to plants? Create list with the class on a giant piece of post-it paper. What do plants need? Put up all the things that the students say and then at the end of the Unit revisit this list to see which is actually needed by plants. For an Engage on another day after discussing Photosynthesis: Hand out lyrics so students can follow along. EXPLORATION Time: 2 Weeks This lab will begin by probing the students about information they will need concerning the set up of their experiment. What defines something as living? Who has heard of photosynthesis before? What is it? Plants do not create energy, but convert it to a useable source. Where do plants get their energy from? Can we use the sun to create It eats and breathes and grows! Several raised hands: plants/leaves creating energy. The sun, nutrients, water, air. No, maybe. 3

4 EXPLORATION Time: 2 Weeks energy? How do plants store the energy that they created? Roots, cellulose, sugar, glucose Hint: we can eat it, think of sweet potatoes, apples and carrots. So when you set up your experiment, be sure to provide ways for your plants to receive those things that they need: Light, CO 2, water, nutrients, etc. Pass out lab worksheet for students to plan the set up for their experiment. Tell them the resources they have available to them and that they must get approval by the teacher before they can actually receive any materials. During the next class period have the students set up their experiment. Over the next 2 weeks have students make observations on the amount of growth that they observe of the Duckweed to be graphed at the end of What is glucose? Can anyone name a molecule that contains any one of those elements? So where do plants get those basic components that they need? Sugar. Water, carbon dioxide, oxygen in the air. Sun, soil, bacteria. 4

5 EXPLORATION Time: 2 Weeks those 2 weeks. Use the remaining portion of the period to direct teach on plant structure and function as well as reproduction. EXPLANATION Time: 2 class periods Have students create a population growth chart that demonstrates the rate of Duckweed growth. Each pair will then present their data and their experimental variable to the class in a short, 5 minute presentation. Review various methods of reproduction in plants (sporic meiosis, cones and pines, pollen, etc.) Which method of reproduction did we observe in the Duckweed? Sexual reproduction and asexual reproduction. ELABORATION Time: 10 minutes This video shows the process of hydroponics. Discuss how plants can get their nutrients from other than the soil if they are regulated by humans. 1. What is the potential for hydroponics? 2. How can this be helpful in areas that 1. Able to grow plants faster, closer together, doesn t take all the nutrients out of the 5

6 ELABORATION Time: 10 minutes have poor soil conditions? soil. 2. Can provide food and crops to places that couldn t support their growth before. EVALUATION Time: 5-10 minutes Pass out giant post-it paper and have students create representation of a plant s life cycle that undergoes sexual reproduction. Also, bring out the list created the first day about What do plants need?. Go through each item and determine as a class if plants really need that item. 6

7 NAME: Partner s Name: Date: PART I: DUCKWEED EXPERIMENT You and a partner will be given one duckweed plant in a 10 oz.,wide rim,plastic cup filled with pond water. These plants may include one to seven "leaves". Each leaf can break off to become its own plant. Your job for the next two weeks will be to count and record the population growth of your "leaves" on the back of this paper. Make a neat and simple graph with the population on the vertical (#"s of leaves) and the 14 days on the horizontal. You should count your population everyday for two weeks. You will also need to replace the water as it evaporates. Use clear pond water if possible. PART 2: You and your partner will team up with another pair to try out a variable between your population and their population. One of your populations (cup of water and Duckweed) will be the "control" and the other will have the one variable or "experimental factor". Some variables that you might want to consider are: A. closeness to the light; B. a fertilizer; C. carbon dioxide content; D. temperature, E. light source, F. kind of water or another variable of your choice. Please check with your instructor about the variable you have chosen. We will to try to use a variety variables. Some questions for thought: 1. What are the life needs of the Duckweed? 2. What effect did you expect that your variable might have on the Duckweed? 3. What, if any, effect did your variable have on the Duckweed population? 4. On a cellular level, can you explain the effect(s) of your variable? 5. How does the Duckweed's cup of water compare and contrast to the planet Earth? Give some of the major differences and similarities. 6. How does your Duckweed population compare and contrast to the Homo sapiens population? Give some of the major differences and similarities. 7. What control do you have over your Duckweed population and what control do you have over the human population? 8. Describe the growth of the Duckweed population. Did the rate of increase, remain about the same, or did it increase or decrease? 9. What factor(s) do you believe limited the growth of the Duckweed population? 10. Why do plants require an outside source Nitrogen, while animals must continually give off Nitrogen? 7

8 11. In terms of complexity & energy potential what are the major differences between the molecules that plants take in and the molecules that animals take in? 8