© 2004 ENSI (Evolution & the Nature of Science Institutes) www.indiana.edu/~ensiweb
This material may be copied only for noncommercial classroom teaching purposes, and only if this source is clearly cited.

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Genetic Jewels:
Building the DNA Model

Created by Thomas Atkins
and Joyce Roderick

 

EVOLUTION
GENETICS
DNA

 SYNOPSIS

Students build short segments (about 10 base pairs) of DNA, becoming intimately involved in its structure. The materials and final product provide a distinctive and useful piece of jewelry (earrings) that can be worn or given as gifts. The kinesthetic experience and durable product combine to make a lasting impression, and something useful deeply learned about a seemingly complex topic.

 PRINCIPAL CONCEPT

The elegant structure of DNA provides for both continuity and change

 ASSOCIATED CONCEPTS

1. DNA provides the machinery for evolution.
2. The sequence of bases in DNA dictates the sequence of amino acids and therefore the functional structure of proteins, which in turn are selected for or against, depending on whether they contribute to survival and reproduction of individuals in their environment.

ASSESSABLE OBJECTIVES

   Students will....

1. Recognize the particular pairing of adenine with thymine, guanine with cytosine
2. Create base sequences which will translate into desired amino acide sequences
3. Translate an unknown sequence into the proper amino acid sequence
4. Create a useful piece of DNA jewelry

 MATERIALS

Beads, wire, needle nose pliers

 TIME

Two 45 minute periods
STUDENT HANDOUTS

(optional) Introduction to Genetic Jewels: Building the DNA Model
(Click here to get PDF copy of this intro)

Online Instructions or hardcopy of same.

 

 

TEACHING STRATEGY

1. This activity could fit nicely as part of your introduction to DNA, its structure and function. This is a particularly novel and engaging approach!

2. Alternatively, this activity could be used in your summing up phase, especially if combined with our "Say it with DNA" lesson, from which students can build sequences that code for their initials or 3-letter nickname.

3. Comments to the teacher: setting the tone and context:
The essential hardware of evolution is the genome. Students can understand change through time, organic evolution, only when they understand the elegance and beauty as well as the utility of DNA, the chemical basis of the gene. Genes drive the production of proteins, the structural and functional building blocks of living organisms.

Cumulative changes in DNA sequences through time, can lead to significant differences in breeding populations, changes which, over vast amounts of time, can lead to speciation. These changes acted on by the environment cause evolution.

In order for students to understand genetics and evolution, they must first know the structure of the DNA molecule. The function of DNA proceeds from its unique structure, a structure beautifully adapted for information storage, transcription, translation into amino acid sequences, replication, and time travel. This activity illustrates that structure in a simple and colorful way which includes details of the purine and pyrimidine nitrogen bases and the relative positions of the sugar-phosphate backbone.

We have found this to be a useful project to teach people about the details of the structure of DNA. Middle school students, high school students, and teachers in our workshops have all successfully constructed the molecule. They reinvent the process and make wonderful embellishments. It's an excellent teaching tool and adornment, as well. We have included this activity among the ENSI materials to help students master the molecule of change.

PROCEDURES

1. Print out the steps, or have students access them online.
2. Provide beads, wires, pliers and other materials, and time for students to build the models.

ASSESSMENT

1. Ask students to exchange their DNA models, to have them checked to be sure that the base pairs are properly matched (and that they can be translated properly, if such was the intent), or
2. Provide samples of DNA models made by others (or yourself) to check for proper base pair matching, mutation, (and meaningful translation, if that goal was included).

EXTENSIONS

& VARIATIONS   

1. If you have a biology or science club, the members might be motivated to make these earrings to order as a fund-raising venture.
2. Consider variations on this activity, making key fobs or wrist-wraps, for example, perhaps using larger beads of different materials. Explore (or have your students explore)... get creative, and share your successes with us.

 RESOURCES

See Appendix in the BeadProject collection for possible sources and costs of beads.

 ATTRIBUTION

Some of the ideas in this lesson may have been adapted from earlier, unacknowledged sources without our knowledge. If the reader believes this to be the case, please let us know, and appropriate corrections will be made. Thanks.

1. Original Source:This activity was created and developed by Thomas Atkins and Joyce Roderick (both in ENSI '92)

4. Edited / Adapted for website by L. Flammer 1/1/2004


 

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