HSCBiology

Inquiry Question 2: How do genetic techniques affect Earth’s biodiversity?

Content Descriptor: Investigate the uses and applications of biotechnology (past, present and future), including:

Analysing the social implications and ethical uses of biotechnology, including plant and animal examples (6.2.1)

Biotechnology definition:

Biotechnology is the harnessing and exploitation of cellular, biomolecular and living processes for industrial and other purposes.

Past uses of biotechnology:

Fermentation of wine was believed to have originated 7,000 years ago with damaged grapes accidentally fermenting. Early farmers enjoyed the taste of the juice compared to that unfermented. In 1891 Hermann Muller demonstrated that bacteria were responsible for types of fermentation in wine. Fermentation of wine is a result of yeast microorganisms converting sugar into ethanol and carbon dioxide. Through this process the microbes use at least 12 core enzymes. Variations can be made to the process to achieve a variety of different flavours; these variations include length of fermentation and type of sugar.

Other past examples include the fermentation of cheese and animal husbandry.

Present uses of biotechnology:

• Fermentationand industrial processes such as the production of ethanol
• DNA Profiling – identification of a specific and unique pattern in DNA. Involves extraction,replication, electrophoresis through gel to separate the different lengths of STR (short tandem repeats) and identification using fluorescent  For more information see (5.5.1)
• Recombinant DNA cloning – pasting a DNA section into a vector which then clones it, suchas a bacteria plasmid. These bacteria are then selected using antibiotics which are then used for research. This can be used for investigating function or mutations as well as characteristics of genes.

Future uses of biotechnology:

Treatment for cystic fibrosis – caused by a mutation in the CFTR gene leading to lack of the mediating enzyme. Causes lung infection and persistent coughing and phlegm. Research is being done into the incorporation of correct copies of the genes into lung cells. This may be through a hybrid virus, one of the natural forms of mutations in cells.

Biotechnology – Case Study A – Aqu Advantage Salmon

• GMO (genetically modified organism) developed in North America. Alters the genes ofAtlantic salmon to include the genes from Chinook salmon, allowing them to grow twice as fast when compared to unmodified salmon while also consuming less food.
• Socialconsiderations – Pose a perceived threat to the livelihood of wild salmon  This is exemplified in Alaska, where the industry employs 60,000 people. Farming of these salmon is expected to out-compete the natural fishing.
• Economic – Aqu Advantage salmon are economically more viable than traditional salmonfishing, being able to control production of fish in much larger quantities for fractions of the  This also may reduce transport costs due to inland fish farms. Furthermore, these farms would be able to increase growth in the fishing sector.
• Cultural – Issues with the labelling and ethical concerns regarding consuming GMO.Consumer awareness can be ensured through labelling 
• Environmental – Agricultural use of these GMO salmon poses a threat to a variety of fish andecosystems should they escape from farms. They may be able to outcompete similar fish in ecological niches, which has implications for biodiversity of entire food webs.

Biotechnology – Case Study B – Bt Cotton

• Project designed to increase the efficiency of the cotton crop. Refers to a group of proteinsfrom the Bacillus thuringiensis strain of bacteria. The genes that code for these proteins are added to the cotton, causing them to secrete toxins which kill insects which feed on them.
• Social considerations – Bt cotton seeds are highly restricted causing farmers to becomedependent on their sale making them vulnerable to market changes. Likewise, those which cannot afford to change seeds in developing nations may be outcompeted.
• Economic – Bt cotton is far more economically viable than traditional cotton, decreasing costof pesticides by 93% in Australia since its introduction in 1997. Bt cotton also has reduced water usage (3-4% lower), which can be costly in rural 
• Cultural – Ethical debate over introduction in developing nations after the instance in India,one of the world’s largest cotton producers. After its introduction in 2003, a crop failure led to farmers being unable to pay back loans for the seeds, leading to large reported suicides between 2004-2006.
• Environmental – As a plant that requires cultivation there is little chance of outcompetingnative plants. While the increased efficiency does reduce land used, it is still supporting agricultural waste from the fashion industry.

Researching future directions of the use of biotechnology:

Areas of research:

• Treatmentof non-infectious disease through altering 
• Control of infectious diseases such as malaria through altering mosquitos so they areinhospitable to the protozoan.
• Research into the cause and treatment of non-infectious disease through study of the humangenome and non-coding 
• Treatmentof cancer and disease through stem cell research.

Cystic fibrosis treatment:

Cystic fibrosis (CF) is caused by a frameshift mutation, causing cells to not produce an enzyme which mediates the conditions in normal humans.

A large area of research is currently dedicated to using biotechnology to reverse the mutation of the CFTR gene. To achieve this reversal, correct pieces of DNA need to be delivered to individual cells.

From there, either the cell incorporated the correct version of the CFTR gene (integrating gene therapy), or it temporarily uses an attached copy (non- integrating gene therapy). While trials in mice have been promising, the appropriate method of delivery of the genes still requires further research. One method currently under investigation is through attachment to a hybrid virus, which delivers the DNA.

The benefit of genetic treatments for CF is that it will likely be effective for any mutation of the CFTR gene and therefore useable by all CF patients.

Other areas of research include non-genetic treatments, such as the development of anti-inflammatory micro-molecules which block multiple of the enzymes involved in inflammation.

Evaluating the potential benefits for society of research using genetic technologies: (6.2.3)

Stem cell research:

Stem cell research is the exploitation of the pluripotent embryonic cells. Under correct conditions, these cells can be manipulated to become other stem cells or differentiated functional cells. This has a variety of applications such as:

• Understandinghow diseases occur and develop through observing the maturity of stem cells
• Regeneratingdamage cells and tissues caused by a variety of conditions
• Testingdrug treatment effectiveness

Stem cells can be sourced from embryonic cells or from stem cells in adult bone and fat tissue. There has been some controversy over the use of embryonic cells for research, regarding the living state of the embryo.

Benefit of stem cell research:

Stem cells could provide a significant benefit to society. Further research could allow stem cells to be used instead of organ transplants, both improving access to healthy organs and significant quality of life. They may also be used in treatment of cancers and blood disease. This will likely help to improve overall quality of life for humans.

While genetic technologies such as stem cell research have significant potential to improve society, there may be unforeseen factors, such as adverse responses to treatments.

Evaluating the changes to Earth’s biodiversity due to genetic techniques: (6.2.4)

Impact on biodiversity:

Genetically modified organisms whether plant or animal will be able to outcompete their unmodified counterparts. A prime example of this is in transgenic sunflowers, which are capable of producing 50% more seeds than unmodified plants. This advantage, as well as more efficient use of resources is feared to cause non-GMO sunflowers to be outcompeted for resources such as land, thus harming biodiversity. There are also possible negative impacts for the existence of entire species, as can be found in the example of AquAdvantage salmon. The creation of these salmon through genetic technologies pose a threat to the biodiversity of a variety of fish and ecosystems, should they escape. These salmon if released could outcompete similar fish in their ecological niche, which has further implications for entire food webs which may rely upon these species for food.

While genetic technologies such as AI may encourage the reduction of genetic diversity through promoting limited alleles, it also enables the uniting of different genetic combinations from vast areas, overcoming geographical barriers. These methods also may promote biodiversity through the increase in genetic diversity, such as the creation of hybrids.

Inquiry Question Review: How does mutation introduce new alleles into a population? (6.2.5)

You should be able to:

• Describemultiple examples of biotechnology
• Evaluatethe overall impact and benefit of various genetic technologies