Back in September, students in EEB321 were asked to identify trees in their local environment to investigate the relationship between biodiversity and area. When I took my first neighborhood walk to study the trees near the closed gates of Brooklyn College, I had some trouble with identifying trees using their leaves. To avoid further scrutiny by residents who saw me staring up at trees with a clipboard, I decided to take some samples back to my apartment. I had unintentionally kept one of those leaves in my desk drawer so when I was first trying out the foldscope in late October, I inspected a piece of that now-crinkly leaf and observed the following:
Even though the leaf was technically dead for weeks, it was surprisingly still green! I guessed the chlorophyll just hadn’t decomposed yet. I am not an expert in botany by any means, so I wonder if the presence of green pigment indicates the cells are still alive (the brown blob is probably an example of a dead cell). If that is the case, then I wonder why the leaf is able to maintain the pigment/chlorophyll if it hasn’t received much water or sunlight in my desk drawer.
Two weeks later, I tried to find something else interesting to look under the foldscope and after looking at some of my own skin cells, I ended up returning to the same piece of leaf on the slide. I predicted that the majority of the cells would have died/turned brown, but oddly found that not much had changed about the leaf:
Although I had looked at a different part of the sample in the slide, I still saw that most of the cells were green. I find it puzzling why these plant cells are still alive after being in my drawer for almost two months. Perhaps the plastic strips I had used to stick the leaf tissue to the slide had preserved them? To test this, I took a new piece of leaf tissue and look at it under the foldscope:
The cells are clearly still alive and well – they’re zombies! Maybe I’ll keep checking on these leaf cells for the remainder of the semester to see how long the pigment lasts.
I conducted this project as part of Professor Pringle’s EEB321 class at Princeton University.