12.7

1. 1. Listen to Track 117.

      Now answer the questions.

   1. What is the main topic of the lecture?

      1. Variations in types of roots
      2. Methods of transpiration
      3. The function of taproots
      4. Improving the water intake of plants

2. 1. Listen to Track 118.

      Now answer the question.

   2. 1. She wants to elicit examples from the students.
      2. She does not believe that taproots are common.
      3. She is trying to trick her students by talking about other kinds of roots.
      4. She forgot what she was about to say.

   3. The professor mentions that plant root systems are typically observed in water. Why does she mention this?

      1. To demonstrate that it doesn’t matter what material plants are grown in
      2. To explain why the typical setup for this type of experiment would not work in this case
      3. To remind students of the importance of using the scientific method
      4. To reinforce the point that taproots are generally used to store nutrients.

   4. According to the professor, why did the researchers grow a species of pine trees in sand?

      1. To add specific fertilizer types
      2. To remove the branching roots
      3. To monitor the intake of water
      4. To control the size of the taproot

   5. According to the professor, what similarity exists between loblolly pines and carrot plants?

      1. Both can be grown in sand.
      2. Both have been extensively studied.
      3. Both rely exclusively on branching roots for transpiration.
      4. Both use taproots to absorb water.

   6. 1. Listen to Track 119.

         Now answer the question.

      6. 1. To imply that the conclusions reached by the lab were incorrect
         2. To emphasize that structure and storage are the most important roles of a taproot
         3. To indicate that the researchers discovered that taproots play a broader role than previously thought
         4. To suggest that MRI technology was not the best tool for this lab to use