Plants & Human Affairs (BIOL106)  -  Stephen G. Saupe, Ph.D.; Biology Department, College of St. Benedict/St. John's University, Collegeville, MN 56321; ssaupe@csbsju.edu; http://www.employees.csbsju.edu/ssaupe

Sponge Lab: Pre & Post Lab Assignments

PreLab:

1. Print & read copies of the lab exercise

2. On a separate sheet of paper, write your hypotheses for exercise 1 and 2 with a brief rationale.

Question 1:  How is the ability of a saturated sponge to hold water affected by the orientation (on edge, flat, on end) of the sponge?
Hypothesis:  If a saturated sponge is placed on edge, then......

Question2:  After the sponges are allowed to drain, which sponge (top, middle or bottom one in the stack) will hold the greatest amount of water?
Hypothesis: 

Post Lab:

1. Complete Table 1 and then....type a one paragraph summary of this exercise that includes answers to the following questions:  What does this exercise tell you about container size and soil water content?  Which shape/size container will dry out most readily?  Plants in which shape/size container will require more frequent watering?  Which shape/size container is it easiest to over-water?  In which container would it be best to include more coarse-textured materials?
    

2. Complete Table 2 and then....

• Plot Column height (cm) vs. water squeezed from sponge (mL)
• Plot Column height (cm) vs. % pore space filled with water.
• Plot column height (cm) vs. % pore space filled with air.
• Write a summary of this exercise including in your response answers to the following questions:  Why is it relatively easy to over-water a plant?  Explain why is it bad to over-water a plant with reference to our results.

Last updated:  02/09/2005 / � Copyright  by SG Saupe / URL:http://www.employees.csbsju.edu/ssaupe/index.html