Category Archives: DNA tools and techniques

VCE Genetics

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In Chapter 9, you learned about genes, chromosomes and patterns of inheritance, including genotypes and phenotypes, multiple alleles, dominant and recessive genes and co-dominance.

In Chapter 10, you learned about the nature, structure and organisation of the genetic material (DNA), including Mendels’ discoveries with pea plants and the genetic code.

In Chapter 11, you learned about genes in action – replication, transcription and translation to produce the proteins that make up all living organisms.

Chapter 12 is all about the tools and techniques we use to investigate and alter the DNA of organisms – DNA profiling and paternity testing, gene transfer and genetically modified organisms. These processes are newly discovered and there is still community debate about their use. It is important to consider the ethical issues surrounding genetic technologies, as our legal system lags behind scientific knowledge and practice. For example, the recent birth of an IVF baby to a 63 year old woman has made headlines in Australia – she was treated overseas, because the procedure is against the law for women over 53 in this country.

 

Welcome Back – Term 3!

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Year 12 students will be counting down the next 14 weeks until their VCE Biology exam on the morning of Friday 30th October. We will start this term with a review of the structure of DNA, using the GTAC resources, “Exploring the structure of DNA“.

On Wednesday 22nd July we will be heading to the University of Melbourne Genetics Department to complete three practical activities that will contribute to your school-based assessment:

  1. An investigation using a DNA tool and a manipulation technique
  2. An investigation of inheritance in Drosophila melanogaster including a review of meiosis in gamete formation
  3. Meiosis in Drosophila

On Friday 4th September you will have the opportunity to travel to Brauer College and participate in GTAC outreach program, “From Hominoids to Hominins”.

On Tuesday 13th October you will be able to attend a “Get into Genes” program as revision prior to your exam.

Human intervention in evolution

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Humans have had an influence on evolutionary processes for much longer than you may have thought – we have tamed wolves and wild cats to become the many breeds of domestic dogs and cats that share our homes today and we have selected cattle, sheep, goats and pigs over many generations for food characteristics. Our main food crops such as rice, corn, wheat, as well as many fruit and vegetables, are very different to their wild ancestors.

Artificial selection, or selective breeding, is the process by which humans breed other animals and plants for particular traits; for example, increased size, fast muscle growth or sweeter taste. This can be a deliberate process, like when farmers choose to breed animals or plants with particular characteristics or it can be accidental. In Asia and Africa, over many centuries, bull elephants with particularly large tusks have been targeted as trophies and for their valuable ivory. As a consequence, individuals with large tusks produce fewer offspring and become less frequent in the population. (Read more about elephant evolution here and here).

In more recent times, due to greater understanding of genetic inheritance and modern gene technology, we have been able to identify specific genes that code for particular characteristics and create new breeds of organisms with beneficial traits – drought tolerance, increased productivity or improved storage life, for example.

Play the videos from ABC Splash “Genetic Engineering of Crops”

Some sites that may be useful for your research project: