February 4, 2010
The structure of DNA – the huge, twisting molecule that contains all the genetic coding used to control functions, development and behavior of all living organisms – isn’t necessarily an easy concept for students in biology classes to grasp.
But given the importance of understanding this structure, Arizona State University life sciences professor Pamela A. Marshall decided it was worth the investment of time to devise a new activity that high school science teachers could use to help their students master the structure and the attributes of DNA.
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Marshall’s efforts recently paid off, as her activity was selected through peer review to be published at www.asm.org">http://www.asm.org">www.asm.org, the Web site for the American Society for Microbiology.
The title of Marshall’s new activity is a mouthful – “Modeling Concepts of 5’, 3’, Antiparallel and Complimentary in DNA Structure,” but it boils down to using students’ own bodies to model DNA structure to give them an idea of how the molecule is formed.
“I noticed in my classes that many students didn’t really understand the structure of this molecule, even though it is taught in several ways at several levels,” says Marshall, an assistant professor in the Division">http://newcollege.asu.edu/divisions/mns/">Division of Mathematical and Natural Sciences (MNS) on ASU’s West campus.
“I thought I’d develop a lesson plan, field tested, that high school teachers could use if they wanted to try a different method to teach this concept.”
In Marshall’s activity, students model the DNA structure themselves, holding hands to represent the way DNA nucleotides connect, and facing each other to model the hydrogen bonding between the DNA strands .
Concepts related to DNA and genetic material are tested on Arizona’s AIMS test for high school graduation.
If that fact were not enough to make students want to learn these concepts, Marshall says it’s important for everyone to understand the basic biology of a cell.
“Modern human medicine is getting increasingly technical and focused at a cellular level,” she says. “Understanding cell biology is now part of being an educated consumer of medical treatment.”
Having taught in the MNS Division in ASU’s New">http://newcollege.asu.edu/">New College of Interdisciplinary Arts and Sciences since 2003, Marshall has developed a reputation for engaging undergraduate students in her laboratory research. In 2008 she received the ASU Faculty Achievement Award for Excellence in Student Mentoring. Since her arrival at the West campus, Marshall has mentored more than 30 undergraduate students, many of whom have gone on to medical school.
“It’s an honor to have an activity posted on the ASM Web site,” Marshall says. “The postings are an excellent resource for helping teachers think about new ways to teach concepts in science.”
Marshall’s new activity is included among the Microbial Discovery Activities on the ASM site. These exercises, designed to encourage the teaching of microbiology in the K-12 basic science curriculum, can be used by parents, teachers, scout troop leaders, or students themselves. All activities use materials easily found at home or at a neighborhood store.
“The Microbial Discovery Activities collection is a great resource for teachers and microbiologists involved in K-12 education,” says Liliana Rodriguez of the University of Texas Health Science Center at Houston, who serves as editor of the collection.
“The exercises follow the National Science Education Standards, are field tested, and are simple enough to be conducted in a regular classroom.”