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AoS 2 How inheritance is explained - DNA barcoding

Onsite
Full Day
Book Program
Year Levels
Unit 2 — How is continuity of life maintained?

Background

The Ecolinc grassland/wetland is a constructed ecosystem containing many indigenous plants from the Western Volcanic Plains of Victoria. Identification of much of the flora present can be made using the ‘Biodiversity of the Western Volcanic Plains’ Flora and Fauna Field Guide. Identification can be investigated further using DNA barcoding. This involves determining and using a gene segment that contains a specific nucleotide sequence that uniquely identifies a particular species. This may be compared to the way a supermarket scanner uses the black vertical stripes on the packaging of a product to identify a purchase.

DNA barcoding is a molecular biology technique that uses a tiny piece of tissue from the specimen for DNA extraction. For plants, the barcode region is targeted with a known gene sequence found in the chloroplasts called Rubisco Large subunit – rbcl. This barcode region is replicated using polymerase chain reaction PCR and then sequenced. Once the DNA barcode is obtained it can be analysed using bioinformatics tools and stored in global databases for future use.

Applications of DNA barcoding include species identification, diagnosis of disease, determining evolutionary relationships, monitoring invasive species and food safety.


Prior Knowledge

No prior knowledge required.


Learning Intentions

In this program student’s will:

  • consider the difference between DNA, genes, alleles and genomes
  • become familiar with the structure of DNA
  • compare DNA sequences for different Ecolinc plant species

Activities

  • Extract plant DNA from several Ecolinc plant species
  • Copy the rubisco gene from plant chloroplasts using PCR
  • Set up and run gel electrophoresis to verify that the genes were copied
  • Use a database to identify the plant species from the copied DNA sequence

VCE links

  • The distinction between a genome, gene and allele
  • The genome as the sum total of an organism’s DNA measured in the number of base pairs contained in a haploid set of chromosomes
  • The role of genomic research since the Human Genome Project, with reference to the sequencing of the genes of many organisms, comparing relatedness between species, determining gene function and genomic applications for the early detection and diagnosis of human diseases.
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