Transpiration Lab Report Guidelines

What goes in the report:

  1. Experimental question that your group investigated.
  2. Hypothesis for your experiment.
  3. Procedure (for the week--not the stomatal peel) that your group followed.
  4. Control Group Treatment
  5. How you kept other variables constant
  6. Data for your stomatal peel stomate density calculation, your week long experiment, and your leaf surface area calculation.
  7. Graph.  There are two valid ways to graph the data.  You can take your pick
  1. Graph showing the percent change in mass of your plants from day 1 to day 5.  You can’t just graph change in mass, because all of the plants didn’t have the same starting mass.
  2. Graph showing the change in mass in terms of amount of mass lost per mm2 of leaf surface area per plant.  This adjusts for the different masses in another, equally valid way.
  3. I am inclined to one line graph for this lab (probably four lines on the same axes), but I could see other ways of doing it, too.  I could see four small graphs (so that they all fit on the same page in a 2x2 grid layout, or maybe averages for the two plants in each treatment (all on the same graph), if you went that way.  There are so many acceptable options.  
  4. Please explain what your graph is showing.  Make sure to include a key, if necessary, and include a reason why you’ve shown your data the way you have.
  5. Make sure all numerical data is in tables and that only relevant data is presented.  Also make sure to include a brief explanation below any table, similar to what you’ve done in your graph.
  1. Conclusion:  Claim Evidence Reasoning format addressing your hypothesis.  Make sure to include some thoughts as to why your data is the way it is in the reasoning part of your experiment that connects to the process of transcription.
  2. Experimental analysis:  Ways to improve/extend your experiment and why each of those improvements/extensions are useful.

Style Guidelines:

  1. Can be typed.  Doesn’t have to be.  Must be highly legible.
  2. Graph can be done electronically or by hand.  Must be neat.  
  3. Needs to be turned in in meatspace, not submitted electronically.
  4. Data can be shared.  All other parts should be your original work.  

Measuring Leaf Surface area (2 ways).

Way 1:  The way that no one in actual science land uses:

  1. Trace the leaves on a graph paper of known grid size.
  2. Estimate the area via clunky box counting, making decisions at the margins for fractions of a box.  
  3. This is going to take a super long and horribly boring amount of time.
  4. What you need to do this:  Graph Paper of known grid size, and leaves.  Make sure all group members have all data by the end of Friday.

Way 2: Basically the only way that anyone who actually does this for realz does it:

  1. Measuring leaf area in a digital photo with ImageJ, a free java-based computer program
  2. There are multiple tutorials on how to do this.  Here’s one in blog format[1].  Here’s a youtube video[2].  These are literally the first two results that I found out of ~65,000 results in a google search for “how to measure leaf surface area using imageJ”.  
  3. Approximately half of you are going to be like “this is too crazy and hard”, and you are not correct.  This is going to take considerably less time than Way 1 does.  
  4. What you need to do this:  Digital Images of all leaves on a white background with a ruler, or other object of known size (e.g. precisely measured banana) showing the appropriate scale in the frame.