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BIOLOGY, M4 EQ-Bank 1 MC

Human activities have significantly impacted species survival throughout history. Which of the following examples best demonstrates how understanding past human-induced extinctions can inform future ecosystem management?

  1. The extinction of the dodo bird due to hunting informs current wildlife protection laws.
  2. The evolution of antibiotic-resistant bacteria guides modern medical practices.
  3. The disappearance of the Tasmanian tiger influences current conservation strategies in Australia.
  4. The domestication of wolves into dogs shapes modern animal breeding programs.
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\(C\)

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  • The Tasmanian tiger’s extinction was driven by overhunting, habitat loss, and competition from introduced species.
  • Modern scientists can learn from this event by prioritising habitat preservation and controlling invasive species to protect vulnerable ecosystems.

\(\Rightarrow C\)

BIOLOGY, M4 2014 HSC 34c

Demonstrate how applications of the Human Genome Project could affect future trends in human biological evolution.   (4 marks)

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→ The Human Genome Project has succeeded in mapping genes and identifying base sequences of the entire genome.

→ Precise locations of disease-causing genes have been discovered, as well as their specific base sequences.

→ Genetic screening allows people to find out whether they hold defective genes. This can show whether themselves, their family or potentially future children are at risk of a genetic disease even before symptoms appear. 

→ Modification of lifestyle could help to prolong life and increase the chances of the individual producing offspring. This could increase the frequency of the defective gene in the population.

→ Pharmaceuticals can be designed to prevent expression of defective DNA using base sequence recognition chemistry.

→ This would mean that holders of a defective gene would not experience a defective genotype and might live longer lives, causing the defective gene to become more common in the humans species as a consequence.

→ CRISPR is an emerging gene-editing technology that can be used to modify, delete or correct precise regions of our DNA. Its use on humans is currently very limited but its potential is promising for treatment of genetic diseases.

→ While somatic gene editing by CRISPR affects only the patient being treated, germ-line editing affects all cells in an organism, including eggs and sperm. This means that future generations who would normally be affected by the genetic disease in question would be unaffected as the defective gene would not be part of their genotype.

Show Worked Solution

→ The Human Genome Project has succeeded in mapping genes and identifying base sequences of the entire genome.

→ Precise locations of disease-causing genes have been discovered, as well as their specific base sequences.

→ Genetic screening allows people to find out whether they hold defective genes. This can show whether themselves, their family or potentially future children are at risk of a genetic disease even before symptoms appear. 

→ Modification of lifestyle could help to prolong life and increase the chances of the individual producing offspring. This could increase the frequency of the defective gene in the population.

→ Pharmaceuticals can be designed to prevent expression of defective DNA using base sequence recognition chemistry.

→ This would mean that holders of a defective gene would not experience a defective genotype and might live longer lives, causing the defective gene to become more common in the humans species as a consequence.

→ CRISPR is an emerging gene-editing technology that can be used to modify, delete or correct precise regions of our DNA. Its use on humans is currently very limited but its potential is promising for treatment of genetic diseases.

→ While somatic gene editing by CRISPR affects only the patient being treated, germ-line editing affects all cells in an organism, including eggs and sperm. This means that future generations who would normally be affected by the genetic disease in question would be unaffected as the defective gene would not be part of their genotype.