Back To All Questions

Phloem Pressure Gradients Across Species

Q.

A scientist is studying sap flow in phloem vessels in three different tree, an American beech, a white oak, and an American chestnut of similar size and age. She found that the composition of the sap was identical among the trees as well as the diameter of their phloem vessels, but the rate of sap flow through the phloem vessels was different. The scientist measured the following pressures at the top (i.e., in the tree crown) and near the bottom (i.e., the base of the trunk) of each phloem vessel.

Which tree has the greatest flow rate (L/hour) of sap through the phloem vessel?
a) beech
b) white oak
c) chestnut

Explain why the tree you selected has the greatest flow rate (L/hour) of sap through the phloem vessel.

PLATUBESCX

Audiences:

Undergraduate

Topics:

Bulk Flow,  Flux,  Biology,  Plant physiology,  Physiology

Special Instructions

This question has two parts; a multiple choice selection followed by an open response.

To analyze your data for questions with Reports Available:

  1. Login to your account on this website
  2. Return to this question
  3. Click on the link below Analyze your data for this question.
  4. On your spreadsheet, verify that the multiple-choice selections have the text of the choice rather than ‘a, b, c’.
  5. Upload your spreadsheet for analysis
  6. Use the ‘Student Text Response Column (Start)’ dropdown menu to select the column containing the student responses to the multiple-choice part of the question.
  7. Use the ‘Student Text Response Column (End)’ dropdown menu to select the column containing the student responses to the open response part of the question.
  8. Both columns containing student responses should now be highlighted in teal in the preview pane.
  9. Add a note (e.g. pre-instruction) to your file if desired

Background Information

Associated Publications

What a Difference in Pressure Makes! A Framework Describing Undergraduate Students’ Reasoning about Bulk Flow Down Pressure Gradients

Jennifer Doherty, Emily Scott, Jack Cerchiara, Lauren Jescovitch, Jenny McFarland, Kevin Haudek, Mary Wenderoth, 2023

Question Instructions

We recommend that you administer these questions as homework and preface the question with these instructions for students:

"For the following question, please respond to the best of your knowledge and using only the information in the question and what you know. Please do not refer to any outside sources (textbooks, notes, internet, etc.). Any reasonable attempt to answer the question will be awarded full credit."

Find Questions

Upload Data

Review