Plants movements

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Bio 103: Fundamentals in Plant Biology. This is a powerpoint presentation discussing about different types of plant movements.

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  • -Enables leaves to be in the best position possible to receive adequate light for photosynthesis
  • Plants movements

    1. 1. QuizQuiz 1. Gametophyte a. Fern b. Male angiosperms c. Female angiosperms 2. Protective covering of the sorus. 3. Nurse cells 4. Do flowers undergo secondary growth? Yes/No (3pts) 5. Structure that holds pollen among gymnosperms 6. Define double fertilization 7. Define pollination 8-10. Functions of flowers
    2. 2. Label the following
    3. 3. Label the following a b c d
    4. 4. ESSAYESSAY Compare and contrast reproduction of angiosperms, gymnosperms and bryophytes.
    5. 5. . There are many types of tropisms : • Phototropism • Geotropism •Thigmotropism • Hydrotropism • Chemotropism • Thermotropism TROPISM Plant growth in response to a stimulus (“tropo” – ”turn”) !! Tropisms allow plants to seek out the best conditions for survival
    6. 6. TROPISM POSITIVEPOSITIVE  If the plant moves TOWARD the stimulus NEGATIVENEGATIVE  If the plant moves AWAY from the stimulus
    7. 7. GEOTROPISM Geotropism is the growth of a plant in response to gravity. Positive Geotropism It is the growth of a plant towards the center of the earth-down with gravity. Ex. roots growing down Negative Geotropism It is the growth of a plant away from the center of the earth- opposite from the pull of gravity Ex. stems grow up Positive Geotropism Negative Geotropism (“Geo” – Earth)
    8. 8. IMPORTANCE OF GEOTROPISM • Pulls roots down to anchor a plant • Roots can get needed water and minerals if they stay in the soil
    9. 9. PHOTOTROPIS MThe growth response of a plant in response to light direction is called phototropism. (“Photo” – light) Ex. Stems growing toward the window to get to the light
    10. 10. THIGMOTROPISM Thigmotropism is the growth of a plant in response to touch/contact. NEXT (“Thigmo” – “touch”) Tendrils on a sweet pea Photo by Christopher Meloche Vines growing on a wall or fence
    11. 11. HYDROTRHYDROTR OPISMOPISMHydrotropism is the growth in response to water. Ex. roots growing toward moisture NEXT (“hydro” – “water”) THERMOTROPISM Thermotropism is the tendency of plants or other organisms to bend toward or away from heat. Ex. curling of Rhododendron leaves in response to cold temperatures. Chemotropism Chemotropism is movement caused by chemical stimuli. Ex. Growth of a pollen tube is always towards the ovules so that reproduction can occur (“Therm” – “heat”) (“Chemo” – chemical”)
    12. 12. MOVEMENTS
    13. 13. Nastic Movement ¤ Nastic Movements are plant movements that are in response to a stimulus (non-directional) ¤Examples:. Temperature, Humidity, & Light Irradiance ¤ The movement can be caused by turgor or changes in growth
    14. 14. Plants That Have Nastic Moveme nt Prayer Plant (Flat) Prayer Plant (Vertical) Due to Daytime Due to Nighttime
    15. 15. Nastic Movement vs. Tropic Movement ¤Nastic Movements differ from Tropic Movements in that the direction of Tropic Responses depend on the direction of the stimuli, whereas the direction of Nastic Movements are independent of the stimuli.
    16. 16. NASTICNASTIC RESPONSESRESPONSES¤ The frequency of these responses increases as intensity of the stimulus increases. ¤ Example of Nastic Response: Opening and closing of flowers (Photonastic response) ¤ Nastic Responses are usually associated with plants: 1. Photonasty: Response to light 2. Nyctinasty: Movements at night or in the dark 3. Chemonasty: response to chemicals or nutrients 4. Hydronasty: response to water 5. Thermonasty: Reponse to temperature 6. Geonasty/Gravinasty: Response to gravity 7. Thigmonasty/Seismonasty/Haptonasty: Response to touch ¤ Notice that the Nastic Responses are named with the suffix “- nasty” and have prefixes that depend on the stimuli
    17. 17. PHOTOPERIODIPHOTOPERIODI CITYCITY ¤ Photoperiodicity is the physiological reaction of organisms to the length of day or night. ¤ Examples: 1. Shortday plants-Morning Glory, Tulip 2. Longday plants-Potato, Poppy 3. Day Neutral-Tomato, Dandelion, Corn
    18. 18. -The term auxin is derived from the Greek word auxein which means to grow. - Auxins were the first plant hormones discovered Functions of Auxins: -Stimulates cell elongation -Stimulates cell division in the cambium -Stimulates differentiation of phloem and xylem -initiates response of bending in response to gravity and light HORMONES
    19. 19.  Coleoptile or stem tip Agar block prevents the movement of auxins in the stem If auxins cannot move through the stem than the stems ability to respond to, say light ,is inhibited. This means that the plant will not be able to grow towards the light as it normally would. Place the tip back on the plant and all is well!! EFFECTS OF AUXIN
    20. 20. If the agar block is placed partially on the stem than the response would be as shown. As the auxin (which is in the agar block) diffuses into that side of the coleoptile, it stimulates cell elongation and the coleoptile bends away from the block.
    21. 21. Cytokinin Functions: -Stimulates cell division Ethylene : -Ethylene, unlike the rest of the plant hormone compounds is a gaseous hormone - stimulates the ripening of the fruit Gibberellins: - Gibberellins affect: The rate of cell division Flowering Increase in size of leaves and fruits Seed and bud dormancy Induction of growth at lower temperatures
    22. 22.  Abscisic acid : -causes trees to lose their leaves in response to winter -buds to go dormant

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