I am still working on the original investigation that I posted in the fall. This project will be my "second investigation" as I need a couple more data points prior to analysis. I have already implemented an edited version of Carla's "Sizing up cells."

This is an example of student output. In the future, I would spend more time formatting the graphs (gridlines, etc), but for this purpose, students were just excited to have made a graph so quickly!!

Kristina,
You are absolutely right. Kids love to look at how many kinds or sizes there are in their own cells. It does broaden there area of understanding.

I did this with my students too (adapted Kristina's adaptation of Carla's) and it still needs some fine tuning. I found that I needed a big block of time with the computers (3-4 days)to get max learning from this investigation. They do like Excel but get confused when measuring with ImageJ easily - biggest hurdle is getting them to set scale before every different picture/measurement.

Kristina, this looks interesting since I teach cells as well. In grade seven, we review cell organelles and functions, however, cell size is only mentioned. Students would benefit from comparing various cells and creating a graph as a visual presentation. Are two class periods adequate for this lesson, or would I need to schedule additional computer time? Our classes are about the same length of time. Also, do you have web sites available to locate scaled cell pictures? This lesson looks great!

Marie, I would suggest providing at least 3 full class periods for this. Additionally, if they have already had practice using ImageJ (just learning how to use the tools) would help them. As Celeste mentioned, they constantly forget to set the scale for EACH picture.
I used pictures from the website: http://www.bioscience.heacademy.ac.uk/imagebank/search/Fullimage.aspx?IDvalues=1363
where you can pick and choose from many images, however, some of the images are difficult for the 7th graders who are just learning about cell parts. I have found great pictures through google images, and I even took some pictures myself with an USB microscope. The hardest part is finding pictures with the scale bar!