classroom activities

Okay OpenOffice fans, show me what you can do. Earlier this week, I wrote about my challenges with a bug in Microsoft Excel that only appears on Windows computers. Since I use a Mac, I didn't know about the bug when I wrote the assignment and I only found out about it after all but one of my students turned in assignment results with nonsensical pie graphs. So, I asked what other instructors do with software that behaves differently on different computing platforms. I never did hear from ... Read more

Here's a fun puzzler for you to figure out. The blast graph is here: The table with scores is here, click the table to see a bigger image: ... Read more

Do different kinds of biomes (forest vs. creek) support different kinds of bacteria? Or do we find the same amounts of each genus wherever we look? Those are the questions that we'll answer in this last video. We're going to use pivot tables and count all the genera that live in each biome. Then, we'll make pie graphs so that we can have a visual picture of which bacteria live in each environment. The parts of this series are: I. Downloading the data from iFinch and preparing it ... Read more

This is third video in our series on analyzing the DNA sequences that came from bacteria on the JHU campus. In this video, we use a pivot table to count all the different types of bacteria that students found in 2004 and we make a pie graph to visualize the different numbers of each genus. The parts of this series are: I. Downloading the data from iFinch and preparing it for analysis. (this is the video below) (We split the data from one column into three). II. ... Read more

What do you do after you've used DNA sequencing to identify the bacteria, viruses, or other organisms in the environment? What's the next step? This four part video series covers those next steps. In this part, we learn that a surprisingly large portion of bioinformatics, or any type of informatics is concerned with fixing data entry errors and spelling mistakes. The parts of this series are: I. Downloading the data from iFinch and preparing it for analysis. (this is the ... Read more

For the past few years, I've been collaborating with a friend, Dr. Rebecca Pearlman, who teaches introductory biology at the Johns Hopkins University. Her students isolate bacteria from different environments on campus, use PCR to amplify the 16S ribosomal RNA genes, send the samples to the JHU core lab for sequencing, and use blastn to identify what they found. Every year, I collect the data from her students' experiments. Then, in the bioinformatics classes I teach, we work with the chromatograms and other data to see what we can find. This is the first part of a four part video series ... Read more

You can get a jump on the Darwin Day festivities. Once again the Alliance for Science is sponsoring an essay contest for Darwin Day. If you download their suggestions for good essay writing, you can get your essay done over winter break and have a good crack at winning on those cash prizes!

The Alliance for Science is pleased to announce our second annual National High School Essay Contest. We invite interested students to submit essays of up to 1,000 words on one of two topics -- Climate and Evolution or ... Read more

This is a fun puzzle. The pink molecule is a protein and the other molecule is a nucleic acid. If I gave you the amino acid sequence of this protein, or the nucleotide sequence of this nucleic acid, what is the probability of finding a similar sequence in a different species (picked at random)? A. High B. Medium C. Low D. It ... Read more

As many of you know, I'm a big fan of do-it-yourself biology. Digital biology, the field that I write about, is particularly well-suited to this kind of fun and exploration. Last week, I wrote some instructions for making a phylogenetic tree from mitochondrial genomes. This week, we'll continue our analysis. I wrote this activity, in part, because of this awful handout that my oldest daughter brought home last year. She presented me with an overly photocopied paper that showed ... Read more

DNA sequence traces are often used in cases where:

1. We want to identify the source of the nucleic acid.
2. We want to detect drug-resistant variants of human immune deficiency virus.
3. We want to know which base is located at which position, especially where we might be able to diagnose a human disease or determine the best dose of a therapeutic drug.

In the future, these assays will likely rely more on automation. Currently, (at least outside of genome centers) many of these results are assessed by human technicians in clinical research labs, or DNA testing ... Read more