植物学 TPO43-L1 Leaves Turn Color

TPO43-L1

Leaves Turn Color

Listen to part of a lecture in a botany class.

 



  1. What is the main purpose of the lecture?
  • A. To explain how the red pigment in leaves breaks down
  • B. To show that leaf color varies based on the tree species
  • C. To introduce a theory about why leaves turn a particular color
  • D. To explain how chlorophyll protects trees in autumn

 

  1. What does the professor imply when she explains why leaves are green?
  • A. She wants to correct a common misconception about the topic.
  • B. She thinks the students are probably already familiar with the material.
  • C. She believes the process is too complicated to discuss in depth.
  • D. She knows that students are often confused about the functions of chlorophyll

 

  1. What does the professor mean when she says that the classic theory is partially right?
  • A. It describes what happens in the summer but not what happens in autumn
  • B. It describes what happens in tree leaves but not what happens in leaves of other plants
  • C. It explains how pigments are synthesized but not how they break down.
  • D. It explains some cases of color change in tree leaves but not all cases.

 

  1. Why does the professor mention painting a car?
  • A. To question why a large amount of anthocyanin is produced just before leaves fall
  • B. To explain why most leaves turn red instead of other colors
  • C. To remind students how cooler temperatures affect the color of leaves
  • D. To show how anthocyanin absorbs sunlight to produce food for trees

 

  1. The professor mentions theories about why leaves turn red that involve predatory insects and fungi. What is her opinion about those theories?
  • A. They are based on careful research.
  • B. They do not completely explain the phenomenon.
  • C. They have not received enough attention.
  • D. They have been proved to be incorrect.

 

  1. According to the professor, why does anthocyanin appear on the upper side of some leaves?
  • A. To help chlorophyll absorb the sunlight
  • B. To maximize the leaves’ utilization of sunlight
  • C. To accelerate the breakdown of chlorophyll
  • D. To protect an important process from the sunlight


答案:
C B D A B D

发表评论

电子邮件地址不会被公开。 必填项已用*标注