AoS 1 & AoS 2: A Devilish Dilemma
Background
Tasmanian devils have recently been devastated by a bizarre transmissible cancer, Devil Facial Tumour Disease (DFTD). Transmitted by biting, DFTD has spread over almost the whole of Tasmania, reaching the west coast in the last 2 or 3 years. Almost 100% fatal, it has led to a decline of at least 80% of the devil population. However, research using genomics shows that the rate of infection is slowing and it is possible that the tumours are beginning to regress due to mutations in the tumour genome.
Prior Knowledge
Some knowledge of mendelian genetics and DNA structure would be an advantage.
Learning Intentions
In this program students will:
- Classify adaptations as either structural, behavioural or physiological
- Identify the role of the Tasmanian devil as an apex predator and a keystone species
- Explain the effect of the decline of the Tasmanian devil on the Tasmanian woodland ecosystem
- Link natural selection with existing genetic variation in a population
- Evaluate pedigrees to establish genetic links between individual Tasmanian devils
- Explain how gel electrophoresis works
- Use the results of their electrophoresis gels to identify individuals that have tumours with the ability to regress
- Discuss the importance of genetic diversity in a population
Activities
Students will:
- Classify Tasmanian devil adaptations
- Determine definite and possible genotypes from Tasmanian devil pedigree charts
- Play Ecological Jenga
- Perform gel electrophoresis
- Discuss ideas to rehabilitate the Devil population
VCE links
This program has links to Unit 2 Area of Study 1 and Area of Study 2.
AoS 1:
- The distinction between genes, alleles and a genome.
- The production of haploid gametes from diploid cells by meiosis, including the significance of crossing over of chromatids and independent assortment for genetic diversity.
Genotypes and phenotypes
- The use of symbols in the writing of genotypes for the alleles present at a particular gene locus.
- The expression of dominant and recessive phenotypes, including codominance and incomplete dominance.
Patterns of inheritance
- Pedigree charts and patterns of inheritance, including autosomal and sex-linked inheritance.
- Predicted genetic outcomes for a monohybrid cross and a monohybrid test cross.
- Predicted genetic outcomes for two genes that are either linked or assort independently.
AoS 2:
Reproductive strategies
- Biological advantages of sexual reproduction in terms of genetic diversity of offspring.
Adaptations and diversity
- The biological importance of genetic diversity within a species or population.
- Structural, physiological and behavioural adaptations that enhance an organism’s survival and enable life to exist in a wide range of environments.
- Survival through interdependencies between species, including impact of changes to keystone species and predators and their ecological roles in structuring and maintaining the distribution, density and size of a population in an ecosystem.
