HSC Biology Syllabus Notes -

Module 6 - Inquiry Question 2

Overview of Week 7’s Inquiry Question – How do genetic techniques affect Earth’s biodiversity?

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

Learning Objective #1 – Analysing the social implications and ethical uses of technology, including plant and animal examples

Learning Objective #2 – Researching future directions of the use of biotechnology

Learning Objective #3 – Evaluating the potential benefits for society of research using genetic technologies

Learning Objective #4 – Evaluating the changes to Earth’s biodiversity due to genetic techniques

Week 7 Homework Questions

Week 7 Curveball Questions

Week 7 Extension Questions

Solutions to Week 7 Questions

Overview of Week 7 Inquiry Question

Since this Week’s inquiry question is essentially exploring how human’s use of biotechnology affects biodiversity on Earth, we should explore the definition of both ‘biotechnology’ and ‘biodiversity’.

Biodiversity is essentially refers to the total variety and variability between & within all classes of species as well as the ecosystems in which they reside.

Yes, that was a handful. This is why biodiversity can be subdivided into three broad categories. These are:

Genetic Diversity – refers to the total variety of genes (allele frequency) within a species.

Species Diversity – refers to the total variety or types of species living on Earth.

Ecosystem Diversity – refers to the total variety of ecosystems (habitats) and the abiotic components interacting within an ecosystem (e.g. components such as water, air and soil) on Earth.

Now, what is biotechnology?

Biotechnology refers to activities involving living cells particularly involving the use of organisms or their materials as tools or for commercial use.

NOTE: Genetic Technology is a branch of biotechnology which we will explore soon.

We will be exploring the relationship between biodiversity and biotechnology in this week’s notes in terms of the benefits, disadvantages, ethics and the future.

This essentially relates back to Module 5 in terms of genetic variation and the continuity of species. By lowering the biodiversity, you will decrease the genetic variation and vice versa.

Why is biodiversity important?

As we have mentioned already, one aspect of biodiversity is genetic diversity within species. If a species population have low genetic diversity (or variation) it would be susceptible to extinction upon changes in ambient environmental selective pressures.

Thus, the genetic diversity (and biodiversity) is critical to the continuity of the species as we have already explored in detail in Module 5 Notes.

Species diversity is also important as we rely on a range of plants, microbes, terrestrial organisms as well as aquatic organisms to manufacture a variety of goods.

These include food (beef, lettuce, fish meats, etc), medicine (e.g. different drugs and vaccines) and many common substances that humans use (e.g. sheep wool for carpets, chair seatings, tennis balls, etc).

There a decline in species diversity would mean the availability of such food, medicine (penicillin from fungus) and common substances may be reduced or completely removed.

The last component of biodiversity is ecosystem diversity. As mentioned in the definition earlier, ecosystem diversity provides abiotic components such as circulation and purifying air, water, erosion control, water level control as well as fertile land for agricultural purposes. The destruction of natural ecosystems will result in a decline in not only species and genetic diversity (thus biodiversity) of the organisms residing in such habitats, but important those abiotic components in sustaining life.

For example, rainforests are critical in not only providing oxygen for terrestrial and aquatic organisms to perform cellular respiration but also in maintaining the CO2 level in the atmosphere. This is important as the level of carbon dioxide in the atmosphere will have any effect on the temperature on Earth. The enzymes in living organisms are sensitive to temperature and thus extreme temperatures would hinder the operations of metabolic processes and can result in death.

It is now clear that preserving biodiversity is important. It should also mentioned that tourists travel around the world each year to explore natural landscapes such as rainforests which are a large source of revenue for many countries.

Learning Objective #1 - Analysing the social implications and ethical uses of biotechnology, including plant and animal examples

Before we start analysing the social and ethical implications from the use of biotechnology, let’s explore what biotechnology entails in a broad sense.

As we have defined earlier, biotechnology refers to activities involving living cells particular involving the use of organisms or their materials as tools or for commercial use.

Historically, biotechnology was focused on selective breeding process which involved selecting parents with favourable traits to produce offspring that is similar high quality & abandoning offspring with traits that are not/less favourable. Moreover, past biotechnology techniques also focused on using microbes to manufacture beer, wine, cheese, bread and many more.

However, as time passed, the use and purpose of biotechnology evolved which we will refer to modern biotechnology which we will refer to biotechnology from this point onwards.

(Modern) biotechnology deals mainly with cellular molecules with DNA. There is only one reason to why biotechnology works. This is because biotechnology operates base on the principle that all living organisms are comprised of the same form of genetic material. That is, DNA nucleotides.

Recombinant DNA technology is one technology widely used across the biotechnology industry which can be used to create transgenic species.

The process of producing a transgenic species starts with the identification of the desired gene to be inserted into an organism. Once the desired gene is identified, FISH (fluorescence in situ hybridisation) technology is used to locate the desired gene in the organism’s DNA for extraction.

The extraction process involves using a gene splicing technique in recombinant DNA technology. In the gene splicing technique, the same restriction enzyme is used to cut the DNA sequence in the organism containing the desired gene and a plasmid DNA molecule (vector molecule) in order to transfer DNA of one species to another.

The use of the same restriction enzymes allow the creation of sticky ends in which complementary base pairing between the plasmid and cut out gene can be performed. Moreover, an enzyme called ligase is used to repair and consolidate the cut out gene so that it combines with the plasmid DNA.

Note that polymerase chain reaction (PCR) is often used to make multiple copies of the gene which is inserted into each plasmids to allow larger quantities of the gene to be produced.

By adding heat to a solution containing the modified plasmid and E coli bacteria, the bacteria will absorb the plasmid into its DNA whereby the plasmid can be copied as the bacteria reproduces in a nutrition rich environment with antibiotics.

Note that the plasmids have naturally genes for antibiotic resistance. Since the nutritional environment in which the bacteria is cultured contains antibiotics, any bacteria that does not absorb the plasmid containing antibiotic resistant gene will be killed. Thus by adding antibiotics in the culture environment, it ensures all surviving (old and new) bacteria carry the desired gene.

This allows multiple copies of the recombinant DNA to be produced by the bacteria (in some cases yeast is used instead). The recombinant DNA can be inserted into a host species to convert it into a transgenic species.

It is important to note that these organisms involved in the DNA recombination process do not need to be related and the technique allows favourable characteristics from one individual to be also be exhibited in another individual (may or may not be the same type of species).
This process is selective as the gene that specifies for the favourable trait can be extracted.
NOTE: In industry, genetically modified organisms (GMO) refers to those organisms with their DNA modified due to mutation (spontaneous and induced). Comparatively, transgenic species with modified DNA are NOT produced via mutation but using techniques such as recombinant DNA technology as mentioned earlier. In reality, manufacturers make GM food and transgenic food synonymous despite them being different!
Fun Fact: Other methods to produce transgenic species include: DNA microinjection, embryonic stem-cell mediated gene transfer, retrovirus-mediated gene transfer, electroporation, etc.

EXAMPLE: Glow in the Dark Rabbits!

For example, through recombinant DNA technology, biotechnologists use a restriction enzyme to cut DNA segments in jellyfish that are responsible for their glow-in-the-dark feature and the same restriction to cut out same section of DNA from rabbits. The glow in the dark jellyfish DNA is inserted into a rabbit mother’s embryo and the rabbit embryos develop into produce a glow-in-the-dark rabbits!

Anyways, a last point that we wish to touch on is that modern biotechnology can be divided into several categories which includes: medical, industrial, food, agricultural, marine and environmental.

We will be focusing on medical, agricultural and marine biotechnology for HSC Biology.

Past (Conventional) biotechnology

This will be the only section focusing on past biotechnology techniques and all other sections in this week’s notes will be referring to modern biotechnology unless otherwise specified.

Past biotechnology techniques can be divided into early and classical biotechnology.

Early biotechnology involved humans growing crops (through the use of seed) such as wheat to make bread dates back to 8000BC by ancient Egyptians. Fast forwarding to 4000BC, some common crops that we see in modern civilisation including potatoes and peas are seen to be grown in America and Eurasia.

At around 1000BC, ancient Babylonians introduced and performed selective breeding on date palms and tomatoes. This involves growing and selecting the offsprings with the most favourable traits such as size and quality and abandoning any crops with less favourable traits.

Ancient fermentation of grapes to produce wines were also common.

In terms of classical biotechnology it is based off with the introduction of genetics which started with Linnaeus’s publication of the science behind classifying plants into different groups in 1735.

About 100 years later, in 1859, Charles Darwin published the Theory of Evolution by Natural Selection. In 1865, the birth of genetics was initiated by Gregor Mendel in his work on cross breeding pea plants. His experimental results led to his proposal of the three major laws of inheritance being – dominance, independent assortment and random segregation, officially marking the birth of genetics studies. This had the significance that genetic materials can be passed on from one generation to another which critical for the operation of modern biotechnology techniques requiring the interaction with species’ DNA.

Mendel’s proposal had the consequences of paving the way for farmers to experiment with cross breeding plants to produce hybrid offsprings with favourable traits of its parents.

Fast forwarding to modern biotechnology, it involves interaction with living cells at a cellular and molecular (DNA) level.

Social implications on the use of biotechnology

The use of biotechnology has benefited the society in many areas as outlined below.

Medical Biotechnology

The insertion of human gene that specify the production of insulin into a bacteria (thus making the bacteria a transgenic species) for replication, scientists are able to produce insulin at a large scale by the bacteria to treat patients suffering from diabetes and saved many lives. This is because insulin is a hormone that is able to regulate the blood sugar level to prevent blood pressure from being excessively high and damage blood vessels. Until 1982, the only method to obtain insulin was from beef meaning that the insulin was scarce quantities.
The extraction of a gene from Hepatitis B virus and combining the DNA of yeast for cloning was the first vaccine produced using recombinant DNA technology. The success of biotechnology not only lowered the cost by improving the efficiency of vaccine production so that vaccines are now widely accessible but also minimised the risk involved in producing vaccines. This is because, prior to the use of biotechnology named recombinant DNA technology, the antigen responsible for Hepatitis B virus needs to be extracted from the blood of affected patients. This inherently involved the risk of contacting and receiving blood-borne diseases.
There are many tools being invented or created to increase the capacity for the value in which medical biotechnology can provide to society. These include the introduction of gel electrophoresis used for DNA profiling and sequencing which we have talked about in Module 5.
Another tool is the growing use of nanoparticles and nanodevices in the growing field of nanomedicine to both directly enhance patient’s immune response, detect signs of cancer, edit genes by delivering enzymes, as well as to perform tissue repairs.
For example, the fragile X symptoms (associated to autism) in mice are lower by delivering an enzyme using gold nanoparticles which alters the DNA of a receptor responsible for autism in mice. This new technique in medical biotechnology of delivering enzymes to edit the genome of individuals is called CRSPR which can be accelerated with the development of nanoparticles to transport such enzymes to desired gene locations.
So medical biotechnology supports the prevention, control and treatment of diseases.

Agricultural Biotechnology

The insertion of genes that specify the production of vitamin C and E in tomatoes help reduce the risk in people developing heart disease.
The “Golden Rice” involves inserting genes into plasmids that specifies for the production of beta carotene which is converted into vitamin A. These plasmids are then transferred into rice embryos to produce Golden Rice which has higher vitamin A concentration than traditional white rice. Golden Rice can help reduce vitamin A deficiency conditions that are suffered by millions of people globally.
Another example involves a gene that specifies for starch product to be inserted into plasmids which are absorbed by a bacterium for replication. This modified plasmid is inserted into the Russet Burbank potato to enhance the starch level. This results in less oil being absorbed by the potato strips upon frying when making french fries. This improves the health of society as there is less fat in french fries, reducing obesity and possibility of heart disease.
The extraction of insect-resistant Bt gene from the bacteria, Bacillus thuringiensis, allows biotechnologists to insert the gene into crops such as corn and cotton to resist crops being invaded by insects and pathogens (e.g. bacteria and virus) as the gene specifies for Bt toxins proteins. This ultimately results in less harmful pesticides (such as insecticides) required and exposed by farmers themselves as the chemicals can cause a range of health issues from respiratory problems to cancer. Pesticides are also toxic to fish as it can reduce the fish’s ability to regulate its internal temperature which can affect enzymes’ ability to catalyse necessary metabolic processes like cellular respiration to sustain life.
Also, due to lower dosage required, the effect of pesticides runoffs into ambient waterways that are harmful to fish can be reduced (although this is an environmental implication rather than societal).
On top of being responsible in increasing the supply of food to the growing world population (more pathogen-resistant crops increases crop yield), agricultural biotechnology also supports in enhancing the nutritional value of food to improve health by preventing nutritional deficiencies.
Agricultural biotechnology can also reduce the risk of diseases (e.g. starch potato case)
Recombinant DNA technology used in the field of agricultural biotechnology lowers the time required for intensive labour care in conventional cross pollination breeding procedures to produce offsprings with characteristics (both favourable and non-favourable) from both parents.

Aquatic or Marine Biotechnology:

Aquaculture is a application of marine biotechnology that involves the culturing of marine organisms to identify genes that are used in both enhancing crop yield, growth of aquatic organisms and treating diseases.

For example, through aquaculture, it was identified that the insertion of a growth hormone gene into salmons are able to accelerate its growth. Faster growing salmons increases global food availability to meet the demands of the growing world population.
The discovery and isolation of the DNA segment that specifies for the anti-freeze protein from the Northern Cod that resides in cold Canadian waters allows scientists to insert them growing tomatoes and strawberries. These crops are able to survive and grow in cold locations around the world that otherwise would not be possible which increases the food availability for the growing world population.
In 2013, the green fluorescent protein can be obtained from a DNA segment in jellyfish and be inserted into rabbits’ embryos to produce glow-in-the-dark rabbits. This allows scientists to verify whether the inserted genes into rabbits are operating as expected serving as a way for animals to produce the medicines (proteins) required to treat diseases in the future. This includes using animals to produce blood-clotting enzymes to treat diseases such as haemophilia which lowers the current production cost in factories that has a fixed cost of over a billion US dollars. This would effectively allow greater accessibility to medicine in developing countries.
Again through aquaculture, the discovery of the gene specifying for the production of calcitonin, a protein hormone that enhances calcium absorption into the body, is located in salmons. This gene can be placed into E.Coli bacteria’s plasmids for replication (recombinant DNA technology). The result is mass production of calcitonin hormone which can be injected into the human body to prevent osteoporosis (bones becoming brittle), affecting over 1 million Australians.

Environmental implications on the use of biotechnology

As the world population grows with increasing demand to increase crop production and yield, the need to clear land and forests to grow crops is necessary. This therefore raises the concern about Earth’s limited land capacity being used up as population grows.

By using biotechnology techniques, the need for deforestation and thus effects of soil erosion are reduced.

As from Year 8 Geography, the tree roots stabilise the soil so removing trees would destabilise the soil and result in soil erosion.

The effects of deforestation and soil erosion extends beyond destroying the habitats and ecosystems of species that reside in the forest/rainforest. But, the loose soil can be carried away by rain which end up in local waterways which increases the water turbidity.

The soil that results in high water turbidity can completely remove by covering underground aquatic habits as well as eliminate larvae that are residing in the waters.

This effectively reduces biodiversity as it decreases ecosystem diversity and species diversity (variation).

With the insertion of Bt genes into crops, the species such as butterflies and beetles can experience a decline in species diversity and thus biodiversity. This has may yield undesirable or unexpected implications on the overall food chain.

Ethical implications on the use of biotechnology

The discussion involving ethics is vital to establish the rights, wrongs, moral standards, responsibilities and justice pertaining to the use of biotechnology. As you can already tell, we can go on forever on this topic so we will only discuss to cover a sufficient scope and depth for you to answer HSC Biology long responses.

Gene therapy involves inserting a gene into an organism’s DNA in replace a defective gene that is responsible for a disease. This is useful as it be assist in the prevention, control and cure of diseases which we will also explore in Module 7 and 8! Furthermore, genes that specify for cytokines production can also be inserted into the affected organism’s DNA to stop the growth of or remove cancer cells.

Well, the ethical implication that comes along with gene therapy involves whether or not gene therapy should be performed on germ cells.

If gene therapy is advanced and refined, there will be ethical issues surrounding the use or misuse of genomic information. For example, although gene therapy is only currently performed in the patient’s cells and not his or her germinal cells, the resulting gametes and offspring of the patient will not be affected.

However, if gene therapy is performed on germ cells, the unborn offspring may be affected without freedom of choice. Furthermore, as gene therapy advances and becomes more refined, the effects of the first few operations on germ cells will be unknown and may yield adverse side-effects on the resulting offspring.

That being said, there are arguments in favour of applying gene therapy to germ-line cells to remove health disparities between people of different ethnicities.

Furthermore, the fact that the introduction of Bt gene into crops are toxic to species such as birds, butterflies and beetles, it has consequences of reducing biodiversity and manipulating evolution.

This subject of manipulating evolution brings forth the idea of “playing as/with god” in which western religions, such as Islamic and Christian religions, strongly disapprove as regard as disrespectful. This is because, as per their religion beliefs, biotechnology involves humans intervening with God’s role in creation life, dictator of death and being, thus, responsible for evolution.

Moreover, as humans are only a small category of species residing on Earth, there are questions pertaining to the equal rights other plant and animal species to survive and whether humans should dictate the survival of many categories of species? This is because, as mentioned already, agricultural biotechnology is capable of altering biodiversity.

Another ethics lies in the area of whether or not the increased global food availability and reduction nutritional deficiency used as justifications for biotechnology are actually being prioritised in supporting the people located in developing countries that require the support the most.

Another ethical issue involves biotechnology reducing biodiversity (in the form of genetic variation) with the majority of the farmers will shift towards using genetically modified food including crops and aquatic organisms having the same genes and potentially outcompeting their respective variants in the population.

Summary of actions to undertake:

At the end of the day, as outlined by the Australasian Association of Bioethics and Health Law (AABHL), it is important to encourage a wide range of stakeholders to participate in the discussion and formation of ethical policies that balances interests of all parties whilst still allowing innovation in the biotech field.
Secondly, the unique ethical responsibilities of stakeholders are required to be addressed and communicated globally. Furthermore, it is important to ensure transparent global communication pertaining to existing and new developments in the codes of ethical conduct. Currently, countries like Africa have negative perceptions that the above the average due to poor relay of biotechnology in term of what it entails and its effects on cost, health and environment.
Lastly, these codes are required to be periodically reviewed and adaptive to new information.

Learning Objective #2 - Researching future directions of the use of biotechnology

As mentioned before, medical biotechnology is a subdivision of the biotechnology field and its future use lies in the prevention, control and treatment of diseases. The future of medical biotechnology holds the advancements in gene therapy which is currently in its infancy.

Currently, gene therapy is still in its infancy stage and refinements are necessary to ensure the safety and efficacy in removing and inserting genes into individual to produce desired results. Some of the current risks pertaining to gene therapy are the event where too many or too few proteins are specified, the patient’s immune response triggers inflammation and many more that would threaten the health of the individual.

The insertion of therapeutic proteins to substitute the absence or low level of protein produced via natural, in-vivo protein synthesis due to a defective gene may be a substitute of gene therapy.

Currently, high-throughout put screening (HTS) techniques that employs computer technologies and robots are used to automate the process to test the ability of various therapeutic proteins. These proteins functions to bind with receptors in the body to relay electrochemical messages to the hypothalamus and initial a desired response. Many of these therapeutic proteins that are approved in the USA by the FDA are also monoclonal antibodies used to treat various cancer diseases and arthritis. Currently, therapeutic proteins is a growing medical biotechnology area as HTS techniques are currently being used to automate the process to explore different therapeutic proteins to cure conditions such as asthma and muscular dystrophy.

Stem cell research, nanomedicine (as mentioned earlier) are also growing fields!

Learning Objective #3 - Evaluating the potential benefits for society of research using genetic technologies

We have discussed potential benefits of research using several genetic technologies for society already. So, we won’t go into detail. The list are some areas which we have already talked about that can yield benefits for society upon future research.

The use of HTS technique to test different therapeutic proteins to cure different medical conditions.
Gene therapy on individual and germ-line cells to cure diseases and disorders and remove health disparities between different ethnic and racial groups.
Aquacultures used to culture aquatic organisms facilitates the discovery of genes that produce new transgenic species that would be beneficial for medical biotechnology (i.e. the jellyfish case, gene to treat osteoporosis disease). Advancement in marine biotechnology can also increase crop and food yields to meet the demands of growing world population (e.g. cold strawberries, cold tomatoes, faster growing salmons examples mentioned earlier).
Research into nanoparticles in the field of nano-medicine can allow the transportation of various drugs or proteins to treat diseases or disorders. For example, using gold nanoparticles to transport enzyme to edit genes as discussed earlier.
Advancements in nanoparticles are able to accelerate the capabilities of delivering various enzymes through the CRISPR (Clustered regularly interspace short palindromic repeats) technique to edit genes to cure diseases and disorders.

Week 7 Homework Questions

Week 7 Homework Question #1: Evaluate the social implications of three different fields of biotechnologies. [7 marks]

Week 7 Homework Question #2: Evaluate the social benefits of three different fields of biotechnologies. [7 marks]

Week 7 Homework Question #3: Describe how the field of biotechnology changed over time. [5 marks]

Week 7 Curveball Questions

Week 7 Curveball Question #1: Evaluate the ethical implications of using biotechnology with named examples from three different standpoints. [5 marks]

Week 7 Curveball Question #2: Explain how the use of biotechnology have resulted in modification of different populations’ genetic diversity. [7 marks]

Week 7 Curveball Question #3: Explain the importance of research in biotechnology and its implications on society with examples. [7 marks]

Week 7 Curveball Question #4: Explain how does genetic techniques affect Earth’s biodiversity? [8 marks]