Transcript Document
Plants Move TROPISM is a biological phenomenon, indicating growth or turning movement a plant in response to an environmental stimulus TROPISM POSITIVE If the plant moves TOWARD the stimulus NEGATIVE If the plant moves AWAY from the stimulus Phototropism Movement of plants toward light Why? Maximize amount of sun for photosynthesis to make their food. Phototropism http://www.youtube.com/watch?NR=1&v=KQOC_bPrqFs&s afety_mode=true&persist_safety_mode=1 Gravitropism Movement of plants in response to gravity Positive is toward gravity (roots grow down) Negative is away from gravity (shoot, stems, and leaves grow up) Why? Allows plants to grow properly and get nutrients and sunlight http://www.youtube.com/watch?v=mYZXax8V_L0&feature=related&safety_m ode=true&persist_safety_mode=1 Hydrotropism Movement by plants toward water. Why? Roots search for and grow toward water, because it is needed for photosynthesis and to support cell structure. http://virtualastronaut.tietronix.com/textonly/act25/text-plants.html Thigmotropism Plants moving in response to touch. Positive is toward touch (vines wrap around structures) Negative is away from touch (some plants close up when touched) Why? to support leaves as they grow higher to reach the sun to make more food (photosynthesis). http://www.youtube.com/wat ch?v=8HeedWWe6VA&featur e=related&safety_mode=true &persist_safety_mode=1 Gravitropism Gravity causes a response in plant growth In the picture above, which part of the plant exhibits positive tropism, and which exhibits negative tropism? Hydrotropism The way a plant grows or bends in response to water Why would it be important for some parts of a plant to be pulled toward water? Thigmotropism Plants What bend and grow because of touch. are some other ways a plant can be “touched”? Phototropism The way a plant grows or bends in response to light. Why do you think sunflowers were given their nickname? Hydroptropism Gravitropism Phototropism Gravitropism Phototropism Thigmotropism TROPISM QUIZ Identify the type of tropism in the following pictures 1 2 3 4 5 6 7 http://www.youtube.com/watch?v=Ze8N V7cvW8k&feature=results_main&playnext =1&list=PL5464C68C7644DD4D&safety_mo de=true&persist_safety_mode=1 8 9 10 http://www.youtube.com/watch?v=8SkK uwbmR5Y&feature=related&safety_mode =true&persist_safety_mode=1 11 http://www.youtube.com/watch?v=9sgg QQuBU40&feature=related&safety_mode =true&persist_safety_mode=1 12 13 http://www.youtube.com/watch?v=mYZX ax8V_L0&safety_mode=true&persist_safet y_mode=1 14 15 http://www.youtube.com/watch?v=8Hee dWWe6VA&feature=fvsr&safety_mode=tr ue&persist_safety_mode=1 16 http://www.youtube.com/watch?v=FC5e BkDJbMs&feature=BFa&list=PL5464C68C7 644DD4D&lf=results_main&safety_mode=tr ue&persist_safety_mode=1 17 18 http://www.youtube.com/watch?v=Zq3U uHlPLQU&feature=related&safety_mode= true&persist_safety_mode=1 19 20 http://www.youtube.com/watch?v=frmyz IhD29Q&safety_mode=true&persist_safety _mode=1