TPO28-L3
Plants’ photoreceptors
Listen to part of a lecture in a botany class.
- What is the lecture mainly about?
- A. The differences in how humans and plants sense light.
- B. An explanation of an experiment on color and wavelength.
- C. How plants sense and respond to different wavelengths of light.
- D. The process by which photoreceptors distinguish wavelengths of light.
- According to the professor, what is one way that a plant reacts to changes in the number of hours of sunlight?
- A. The plant absorbs different wavelengths of light.
- B. The plant begins to flower or stops flowering.
- C. The number of photoreceptors in the plant increases.
- D. The plant’s rate of photosynthesis increases.
- Why does the professor think that it is inappropriate for certain wavelengths of light to be named “far-red”?
- A. Far-red wavelengths appear identical to red wavelengths to the human eye.
- B. Far-red wavelengths have the same effects on plants as red wavelengths do.
- C. Far-red wavelengths travel shorter distances than red wavelengths do.
- D. Far-red wavelengths are not perceived as red by the human eye.
- What points does the professor make when she discusses the red light and far-red light that reaches plants?
- A. All of the far-red light that reaches plants is used for photosynthesis.
- B. Plants flower more rapidly in response to far-red light than to red light.
- C. Plants absorb more of the red light that reaches them than of the far-red light.
- D. Red-light is absorbed more slowly by plants than far-red light is.
- According to the professor, how does a plant typically react when it senses a high ratio of far-red light to red light?
- A. It slows down its growth.
- B. It begins photosynthesis.
- C. It produces more photoreceptors.
- D. It starts to release it seeds.
- In the Pampas experiment, what was the function of LEDs?
- A. To simulate photosynthesis.
- B. To simulate red light.
- C. To add to the intensity of the sunlight.
- D. To provide additional far-red light.
答案：
C B D C A B