Download Laura Hunter: Using DNA Barcoding in Food Webs

Lesson Name: Using DNA Barcoding in Food Webs
Learning objectives: To investigate the technology of DNA barcoding and apply it to the building of a food
web of Gray’s Reef.
Enduring Understandings for the lesson:
• A food chain represents the flow of energy from producers to consumers
• Consumers include herbivores, carnivores, decomposers and omnivores
• Trophic levels include producers, consumers, and decomposers
• DNA stores genetic information in its nucleotide sequence (genes)
• Identify DNA as the cellular component responsible for the genetic code
Georgia Performance Standards Addressed:
SB2. Students will analyze how biological traits are passed on to successive generations.
SB3. Students will derive the relationship between single-celled and multi-celled organisms and the
increasing complexity of systems.
SB4. Students will assess the dependence of all organisms on one another and the flow of energy and matter
within their ecosystems.
Grade level: 9
Materials:
Organism cards-cut in baggies with strips of digestive DNA (I put these in plastic eggs within the baggie)
Simulated BOLD Database Resource
Food Web Field Notes Resource
Poster or poster paper
Computer access for extensions
Time needed: 2 class periods
Background information:
In 2003, scientists introduced a new technology to use DNA technology for species identification. This
technology uses a standardized gene location from the genome and compares it from one species to the next.
This standardized gene is a 648 base-pair region in the mitochondrial cytochrome c oxidase 1 gene (“CO1”).
It is most effective at identifying species of animal like butterflies, fish, and flies but is less effective at
identifying plants since the gene does not evolve fast enough in plants. One use of this technology is in
clarifying relationships in food webs.
Learning Procedure:
1. Hook: Video of current Gray’s Reef Research- http://www.youtube.com/watch?v=B-NzzKF3Fik
2. Introduce Activity
3. Teach:
a. Graffiti Poster of Food webs & trophic levels-Review
b. Article about DNA Barcoding- http://ibol.org/about-us/what-is-dna-barcoding/#
4. Students will go diving for organisms and identify the organisms first.
5. Students will analyze the digestive contents of each organism to identify their food sources.
6. Students will then create a food web of the imaginary reef and write up a description of their food
web.
Evaluation:
Student Question Sheet
Food Web with description
Challenge Questions
Extensions:
Scientists usually only find a small sample of DNA but need a much larger sample in order to test it.
Research and create a quick fact sheet about the technique scientists use to amplify a sample of DNA.
DNA barcoding uses a gene found in mitochondrial DNA. Research the mitochondrial DNA and give
examples of other research done using mitochondrial DNA.
Research an additional organism from each tropic level at Gray's reef and add them into your food web for
the newly discovered reef.
Research environmental threats to Gray’s Reef and other marine environments along the southeast US coast.
Choose 1 threat and write up a 1 page summary of the issue, how it threatens the ecosystem, and ways the
impact can be lessened.
Resources:
Benthic Fauna of Gray’s Reef- http://seamonsters.noaa.gov/
Gray’s Reef National Marine Sanctuary: An Educators Handbook
An Illustrated Field Guide to the Fishes of Gray’s Reef National Marine Sanctuary
Encyclopedia of Life- http://eol.org/
Barcode of Life- http://www.barcodinglife.org/