Principles of Biology : Laboratory

Lab 7 : Respiration

Not only did we modify this lab beyond recognition, we also had numerous difficulties in constructing the respirometers and keeping them in the water baths (for temperature control). Because of that, I have decided that you will NOT NEED to turn in your lab books with your lab report on Monday. That is because I incorporated the questions I want you to answer on this page in the Analysis and Conclusions section. So, On Monday, just turn in the lab report.
Theme: This lab explored room temperature respiration rates in three plants: beans, oats and alfalfa.

Materials and Methods: "Biology Lab Manual" by The College Board, 2001. pages 54-63. Modified by using 3 types of sprouts, measurements and calculations of plants in grams, no controls and only at room temperature.

Results: Class data is used in this report. See http://www.siskiyous.edu/class/bio1/lab7/respiration.data.html

Analysis and Conclusion Section :
The first thing we want to do is to calculate some new numbers from our data.

1) Our rate data is given in ml per sec. For each data entry calculate the rate in ml/minute for all the rate data. This will be reported in a table, as indicated below.
2) Take the new data and, again for each plant, find the average rate. Report in table.
3) Calculate the average mass of the samples for each plant type.
4) For each average reported in 2) above, divide this average by the appropriate mass in grams. This will give us three ml/min used per gram of plant values: one for each plant type. Record in the last line in the table.


 Oats
 Alfalfa
 Beans
Respiration Rate in ml/minute


--- Group 1
 <recaculated data from the 1st group>
 <recaculated data from the 1st group> <recaculated data from the 1st group>
--- Group 2
 <recalculated data from the 2nd group>
 <recalculated data from the 2nd group> <recalculated data from the 2nd group>
--- Group 3

<recalculated data from the 3rd group>
Average Respiration Rate for each Plant
 <put in average for oats heres>
 <put in average for alfalfa here>
 <put in average for beans here>
Average Mass of Plant Sample
 <put in average mass of oat samples>
 <put in average mass of alfalfa samples>
 <put in average mass of bean samples>
Avergage Rate per gram of plant <put in average respiration rate per gram here>
 <put in average respiration rate per gram here> <put in average respiration rate per gram here>


Present this table in the Analysis and Conclusions section, followed by a paragraph or two which incorportate the following questions:

1) What did we attempt to do in this lab?
2)  Explain, in words, the design of the respirometer. What was the function of the KOH soaked cotton? The "non-absorbant" cotton? The water bath?
3)  Does the data indicate that respiration occurred? Explain.
4) How do the average respiration rates compare to one another? Based on our data, which plant has the fastest respiration rate per gram? The slowest?
5) What confidence to you have in our data? Briefly explain why. ( the answer here can be either   "complete," "high," "some," "low,"  or "none.")
6) What would you do different if you were to conduct this experiment again?

Hint: You are encouraged to use a spreadsheet for this. Did you know that you can copy and paste a table from the web into Excel? For my own records, I copied our data table into Excel, then below that I copied the above table into Excel and set up the formulas for it to do the math! You don't have to do this for this lab, but you might want to try.

Thursday, October 9, 11:00 a.m.