AP Biology 4.2 Free Energy and Molecular Building Blocks
AP Biology 4.2 Free Energy and Molecular Building Blocks. What is a plant's response to light known as?
|AP Biology||Free Energy and Molecular Building Blocks|
|Growth, reproduction, and maintenance||Systems require energy input|
|Test Prep||AP Biology|
Bacteria cells, including E-coli, swim toward plant roots like they’re being called home [E-coli cell moving towards a plants roots]
These bacteria are taken up into the roots where they’re used as nutrients.
Sounds like… the wrong answer, too.
Now onto circadian rhythms. [A jamaican band singing on stage]
No, that’s not the newest reggae band to break into the Top 40.
The term actually describes the biological clock of plant life.
i.e. the flower petals closing at nightfall… [A flower petal closing at night time]
…the leaves changing their position after dark…
…and then the neighborhood rabbit eating most of your berries around midnight. [A rabbit eating a blackberry]
OK, that’s not a true example of circadian rhythms, but Answer D isn’t true, either.
So cross out D!
Then there is answer B. Photoperiodism.
Various plants respond differently to seasonal changes in the length of daylight. [Two different plants and a light bulb appears]
Poinsettias and chrysanthemums have a certain… snob appeal toward shorter days.
While lettuce and petunias are examples of plants that “party hearty” when days are [lettuce and petunias at the beach partying]
That is what photoperiodism is about…proving it is not the correct answer.
Looks like the only one left is C.
Phototropism is a response by plants to light from a particular direction. [A sunflower on the window sill responding to the sunlight]
Ever notice how the leaves on that potted plant your mom has on the windowsill appear
to be get real cozy with the glass?
If you go ahead and turn that plant around 180 degrees… without dropping it… [Man turning a plant pot around]
…come back in a few hours and its leaves will be pointed toward the window again.
Welcome to the world of “tropisms”, and in particular phototropism, the correct answer
to our exercise. [Phototropism circled as the correct answer]
If you got this one right, you may spend some time near your favorite window.
Don’t have too much fun… [Man stood waving by the window]