Wo-oah We’re Halfway There
Hi everyone! I apologize for the delay in posting—I had an immunology exam due this afternoon and a physics exam yesterday, so I’ve been pretty busy studying the past few days, which means I have a lot to catch you up on. On Monday we had our third Monday meeting of the year, in which Professor Wilson talked to us about plant anatomy, and how to identify different kinds of plants and their physiology based on their physical characteristics. At the end of the lecture we were presented with seven different plants, and using the information we learned during the lecture, tried to identify what they were—which was actually really tricky! One of the plants, a Psilotum (the first image at the bottom is a picture of one) looked like a bunch of sticks covered in small knobs, but it was actually a kind of fern that diverged from the rest of ferns about 340mya and doesn’t have any leaves (I definitely wouldn’t have guessed that). Another plant, a Dioon (the second picture at the bottom) looked like a giant fern, but it was actually a type of gymnosperm. The leaves look soft but they’re actually really hard and sharp, and full of mucilage. Dioons have been around since the time of dinosaurs, and they’re the kind of plant that typically comes to mind when I think about movies like Jurassic Park. It was a really interesting lecture that made me rethink what I (little) I know about plants so far, and provided a good segue into Wednesday’s lab period.
In lab Wednesday, we had to work on a number of tasks. Unfortunately, the transformed bacteria we plated last Friday didn’t grow any colonies (which was really strange, and makes us think that maybe there was something wrong/we did something wrong with our competent cells), so task #1 on Wednesday was transforming new cells and re-plating them. I went in to look at them today, and we have colonies growing on the plates, but they’re all black… so we may have even more problems tomorrow. At the same time, we worked on task #2, which involved the culture-dependent portion of our experiment, taking bacterial colonies and performing PCR on them to amplify a specific sequence of DNA that will help us determine what kind of bacteria they are. Tomorrow in lab we’ll run a gel to see if the PCR went well, so I have my fingers crossed! Our third task, which relates to what we learned on Monday, was taking sections of our bamboo plant, making stained slides of them and then viewing them under the microscope to find structural features of the leaf that might make it habitable to various bacterial species. Something we learned about bamboo during this process, which I was not aware of, is that bamboo is made of 10% silica, making our sample both really difficult to cut through with a razor, and nearly impossible to stain (it made me realize just how powerful panda jaws must be!) We learned that bamboo stems have a leaf base, calling sheathing, wrapped around them, which also made cutting them difficult, because the two kept separating. Below are pictures of our bamboo stem and bamboo leaf section slides—note that the bamboo leaf looks like tiny bamboo stalks up close!
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- Psilotum, Photo Courtesy of UCC.edu
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- Dioon, Photo Courtesy of Wikipedia
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- Stained Bamboo Stem Section
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- Stained Bamboo Leaf Section
September 28th, 2012 at 6:18 pm
I agree with you, Carson, that identifying the different kinds of plants that Professor Wilson brought in on Monday was not an easy task! The photos you posted of your stained Bamboo steam section and leaf section look really cool. We took sections of leaves from a dicot. Unlike your samples, ours were not particularly difficult to stain. I found the mid-ridge section of our leaf fascinating because we could see little hairs that evolved to serve as protection from insects!