Inquiry Question 2: How do genetic techniques affect Earth's biodiversity?
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; researching and evaluating the development and use of a biotechnology
A focused answer to the HSC Biology Module 6 dot point on biotechnology uses. Agricultural (Bt cotton, golden rice), medical (recombinant insulin, gene therapy), industrial (rennet, biofuels) and forensic applications, with a balanced analysis of the social and ethical implications.
Reviewed by: AI editorial process; not yet individually human-reviewed
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What this dot point is asking
NESA wants you to know specific named biotechnologies, what they do, and how to evaluate their social and ethical implications. Use one detailed example per category (agriculture, medicine, industry) rather than a long superficial list.
The answer
Biotechnology is the use of living organisms or their components to make products or processes for human use. Modern biotechnology relies on recombinant DNA, fermentation and increasingly on genome editing.
Agricultural biotechnology
- Bt cotton (transgenic insect resistance)
- The cry1Ac gene from Bacillus thuringiensis is inserted into cotton, where it expresses a Cry protein lethal to bollworm larvae. Reduces pesticide spraying, increases yield, and now accounts for the majority of cotton grown in India, China, the United States and Australia.
- Golden rice (transgenic nutritional enhancement)
- Rice engineered to express beta-carotene (vitamin A precursor) using genes from maize and a soil bacterium. Aims to reduce vitamin A deficiency in populations dependent on rice. Approved in the Philippines in 2021. Critics argue dietary diversification would address the deficiency without GM crops; supporters point out diversification has failed for decades in the affected regions.
- Herbicide-tolerant crops
- Soybean, canola and corn engineered with bacterial EPSPS gene confer resistance to glyphosate, allowing farmers to spray over a growing crop. Increases yields and reduces tillage, but selects for glyphosate-resistant weeds and concentrates farm income towards seed and chemical companies.
Medical biotechnology
Recombinant human insulin (Humulin, 1982). The first commercial recombinant drug. Human insulin gene is inserted into E. coli using a plasmid vector; bacteria express and secrete insulin, which is purified for clinical use. Replaced porcine and bovine insulin and removed allergic complications.
The recombinant-insulin pathway is the model example for "describe a biotechnology" questions, so know its five steps in order: isolate the gene, insert it into a plasmid, transform the bacteria, culture them in a bioreactor, and purify the insulin.
- Recombinant vaccines
- Hepatitis B and HPV vaccines use yeast-expressed viral surface proteins rather than live or attenuated virus, removing infection risk during manufacture.
- Gene therapy
- Inserting a functional copy of a gene into a patient's cells to correct a genetic disease. Examples: Luxturna (RPE65 for inherited blindness, approved 2017), Zolgensma (SMN1 for spinal muscular atrophy, approved 2019).
- Monoclonal antibodies
- Engineered antibodies (e.g. trastuzumab for HER2-positive breast cancer) target specific cell-surface markers with minimal off-target effects.
Industrial biotechnology
- Recombinant chymosin (rennet)
- Calf rennet historically extracted from slaughtered calves' stomachs is now produced in genetically modified Aspergillus or yeast, supplying the cheese industry without animal slaughter and at lower cost.
- Biofuels
- Engineered microbes ferment plant biomass into ethanol or biodiesel as renewable transport fuel.
- Bioremediation
- Bacteria such as Pseudomonas putida engineered to metabolise oil hydrocarbons or heavy metals at contaminated sites.
Forensic and reproductive biotechnology
DNA profiling. Short tandem repeat (STR) analysis identifies individuals from a blood, saliva or tissue sample. Used in criminal forensics, paternity testing and identification of disaster victims.
Reproductive cloning. Somatic cell nuclear transfer (Dolly the sheep, 1996) and embryo splitting are used in livestock breeding for high-value animals (champion racehorses, prize bulls). Banned for human reproduction in most jurisdictions.
Social and ethical considerations
Benefits. Higher yields, fewer pesticides, cheaper medicines, replacement of animal-derived products, treatments for previously untreatable diseases.
Concerns.
- Intellectual property. Patents on seeds and gene therapies concentrate control with a few corporations and raise prices.
- Access equity. Million-dollar gene therapies are out of reach for most patients globally.
- Environmental. Gene flow to wild relatives, resistance evolution in target pests, non-target ecological effects.
- Religious and cultural. Some communities oppose transgenic organisms on religious or "playing God" grounds.
- Animal welfare. Cloned and transgenic livestock face higher rates of developmental abnormalities.
- Consent and dual use. Germline gene editing raises consent issues for future generations; gene drives could intentionally drive species extinct.
Summary table
| Application | Sector | Named example | Mechanism |
|---|---|---|---|
| Insect resistance | Agriculture | Bt cotton | cry1Ac gene from B. thuringiensis |
| Nutritional enhancement | Agriculture | Golden rice | Beta-carotene biosynthesis |
| Diabetes treatment | Medicine | Humulin | Human insulin gene in E. coli |
| Gene therapy | Medicine | Luxturna | RPE65 gene in viral vector |
| Cheese production | Industry | Recombinant chymosin | Calf gene in Aspergillus |
| Identification | Forensics | STR profiling | PCR amplification of microsatellites |
Examples in context
Example 1. Bt cotton in northern NSW. Cotton growers in the Namoi and Macquarie Valleys have planted Bollgard 3 cotton since 2016. The plants contain three Bacillus thuringiensis genes that produce insecticidal proteins lethal to Helicoverpa caterpillars (cotton bollworm). The Australian Cotton Research and Development Corporation reports that pesticide spray applications fell from around 12 per season in the 1990s to fewer than two per season today, because the in-plant Bt toxin replaces broad-spectrum sprays. Cotton Australia data also show insectivorous bird and beneficial insect populations recovering on Bt farms. Growers must, however, plant non-Bt refuge crops alongside Bt cotton to slow the evolution of Bt-resistant caterpillars, an industry-wide stewardship plan.
Example 2. Recombinant human insulin replacing pig insulin. Until the early 1980s, type 1 diabetics in Australia used insulin purified from pig pancreases collected from abattoirs, which provoked immune reactions because porcine insulin differs from human insulin by one amino acid. In 1982, Eli Lilly's Humulin became the first recombinant insulin: the human INS gene was inserted into Escherichia coli using a plasmid vector, the bacteria expressed the protein, and the insulin was extracted by chromatography. Today Australian pharmacies dispense recombinant insulin (Humulin, Novolin) almost exclusively. This biotechnology allows scalable, immunologically identical insulin and removes dependence on slaughterhouse supply.
Try this
Q1. Identify two ethical concerns associated with planting genetically modified Bt cotton in Australia. [2 marks]
- Cue. Possible answers include patenting and seed-saving restrictions, gene flow to native plant relatives, evolution of resistance, and concentration of agricultural power in seed companies.
Q2. A pharmaceutical company produces recombinant human growth hormone using genetically modified Escherichia coli. Calculate the relative cost advantage if a 1000 L bioreactor yields 50 g of hormone per batch versus extraction from 100 cadaver pituitaries yielding 4 mg per pituitary. [3 marks]
- Cue. Bioreactor yield is 50 g (50000 mg); cadaver yield is 100 by 4 = 400 mg. The bioreactor produces 125 times more per batch, plus avoids cadaver-derived prion risk (Creutzfeldt-Jakob).
Q3. Evaluate the use of recombinant DNA technology in agriculture. (a) Identify one specific agricultural biotechnology used in Australia. (b) Describe one benefit and one risk. (c) Justify whether the benefit outweighs the risk in your view. [1+2+3 marks]
- Cue. (a) Bt cotton (or canola). (b) Reduced pesticide use; resistance evolution or gene flow. (c) A clear judgement supported by evidence such as Cotton Australia data, with reference to the refuge-crop stewardship model.
Exam-style practice questions
Practice questions written in the style of NESA exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
2024 HSC4 marksOne-Eyed Jack, a rescue dog that had lost an eye through injury, was cloned, and the clone was born with two eyes. Describe how animals like dogs can be cloned.Show worked answer →
Describe somatic cell nuclear transfer (SCNT) as a sequence of steps. Sample answer: The egg of a host animal is enucleated (its nucleus removed). The nucleus of a body (somatic) cell of the animal to be cloned is removed and inserted into the enucleated egg to produce a zygote. The zygote is stimulated to divide (e.g. by an electric charge), then transplanted into a surrogate mother's uterus. After a gestation period, a cloned animal is born. (The clone has two eyes because it inherited the original dog's intact genetic code - the lost eye was an injury, not a genetic change.) Marks: 4 = describes how animals can be cloned; 3 = outlines the process; 2 = some understanding of cloning; 1 = relevant information. Common error: giving a general outline rather than describing the actual cloning steps.
Source: NESA 2024 HSC Biology examination and marking guidelines.
2022 HSC5 marksBt cotton is genetically engineered to produce an insecticide that kills cotton bollworm. Graphs show national cotton yield, % Bt cotton grown, total insecticide use, insecticide use against bollworm, and insecticide use against another pest (hemiptera). To what extent do the data support the use of Bt cotton as a method of disease control in cotton?Show worked answer →
Weigh the evidence across multiple graphs and reach a qualified judgement linked to natural selection. Sample answer: Initially Bt cotton reduced insect damage and insecticide use: as Bt cotton was adopted, insecticide used against bollworm fell, eventually to zero, suggesting Bt cotton effectively controlled bollworm disease. However, once most cotton was Bt cotton, insecticide use against hemiptera increased markedly, to higher than before Bt cotton. Removing bollworms gave hemiptera a survival advantage, so they became the dominant pest - a new cause of disease. Judgement: the benefit of Bt cotton for disease control was temporary / short-term and needs to be complemented by pesticides. Marks: 5 = thorough understanding linking Bt cotton, insecticides, disease control and natural selection, comprehensive analysis and an informed judgement; 4 = sound; 3 = understanding with benefits/limitations; 2 = one benefit or limitation with data links; 1 = relevant information. Engage with all stimuli and weigh advantages and disadvantages.
Source: NESA 2022 HSC Biology examination and marking guidelines.
2025 HSC7 marks'Genetic technologies are beneficial for society.' Evaluate this statement.Show worked answer →
Name specific technologies, give benefits and drawbacks, and make an overall judgement. Sample answer (key points): In recombinant DNA technology, genes can be cut and pasted between organisms using ligase enzymes - e.g. the human insulin gene transferred into bacteria allows cheaper, more readily available insulin, increasing the life span of diabetes patients. Technologies such as CRISPR can control disease-causing pest populations (e.g. mosquitoes causing dengue), reducing vector-borne disease incidence, giving healthier populations and reduced strain on health systems. Other beneficial technologies: artificial insemination, artificial pollination, cloning. Arguments against: unintended health effects, environmental risks, and ethical concerns. Judgement: these technologies have largely benefited society - improving access to drugs, life expectancy and quality of life. Marks: 7 = extensive understanding of impacts AND a relevant judgement; 5-6 = thorough with a judgement; 3-4 = sound understanding; 2 = some understanding; 1 = relevant information. Common error: inconsistent judgement and referring to 'biotechnology' generally without naming specific technologies.
Source: NESA 2025 HSC Biology examination and marking guidelines.
2025 HSC3 marksCompare the processes of artificial insemination and artificial pollination.Show worked answer →
Give at least one genuine similarity and one difference (comparison, not two separate descriptions). Sample answer: A similarity is that both processes involve the gametes of an organism (assisting fertilisation). A difference is that artificial insemination occurs only in animals (introducing male gametes/semen into a female), while artificial pollination occurs only in (flowering) plants (transferring pollen from anther to stigma). Marks: 3 = compares the two processes (similarity and difference); 2 = incomplete comparison; 1 = some relevant information. Common error: listing separate descriptions instead of comparing, or describing IVF rather than insemination.
Source: NESA 2025 HSC Biology examination and marking guidelines.
Practice questions
Original practice questions graded from foundation to exam level, each with a full worked solution. Try them before revealing the solution.
foundation2 marksDefine biotechnology and give one named agricultural example.Show worked solution →
1 mark - definition. Biotechnology is the use of living organisms (or their components/processes) to make products or processes useful to humans.
1 mark - named agricultural example. Any correct named example with its purpose, e.g. Bt cotton (transgenic cotton carrying a Bacillus thuringiensis gene that makes an insecticidal protein lethal to bollworm). Naming "GM crops" generally does not earn the mark - a specific named example is required.
foundation3 marksOutline how recombinant human insulin is produced using genetically modified bacteria.Show worked solution →
- 1 mark - isolate and insert the gene
- The human insulin gene is isolated and inserted into a bacterial plasmid (vector) using restriction enzymes and DNA ligase to form recombinant DNA.
- 1 mark - transform and express
- The recombinant plasmid is taken up by bacteria (E. coli), which are transformed; as the bacteria reproduce they transcribe and translate the gene, expressing human insulin protein.
- 1 mark - culture and purify
- The bacteria are grown in large fermenters/bioreactors and the insulin is extracted and purified for clinical use.
A response that omits the vector/plasmid, the transformation step, or the culture-and-purify step caps below full marks.
foundation2 marksIdentify one industrial and one medical application of biotechnology, naming the product in each case.Show worked solution →
1 mark - industrial. A named industrial product, e.g. recombinant chymosin (rennet) produced in genetically modified fungi/yeast for cheese-making (or biofuel ethanol from engineered microbes).
1 mark - medical. A named medical product, e.g. recombinant human insulin (Humulin), a recombinant hepatitis B vaccine, or a gene therapy such as Luxturna. The mark requires the named product, not just the sector.
core4 marksCompare agricultural and medical biotechnology, referring to one named example of each.Show worked solution →
Award up to 4 marks for a genuine comparison (a stated similarity and stated differences) supported by a named example in each sector.
- Similarity (1 mark)
- Both use recombinant DNA technology - a gene of interest is transferred into a host organism so that a useful product or trait is expressed.
- Agricultural example and purpose (1 mark)
- Bt cotton carries the cry1Ac gene from Bacillus thuringiensis; the plant itself expresses an insecticidal protein, so the trait is built into a crop grown in the field to raise yield and cut pesticide use.
- Medical example and purpose (1 mark)
- Recombinant insulin is made by E. coli in a contained bioreactor; the product is purified and given to patients to treat type 1 diabetes.
- Point of difference (1 mark)
- Agricultural biotechnology releases the modified organism into the environment (raising gene-flow and resistance concerns), whereas medical biotechnology produces a purified product in a contained facility (raising access, cost and consent concerns instead).
A pair of separate descriptions with no explicit similarity or difference caps at 2 marks.
core5 marksGolden rice is engineered to produce beta-carotene (a vitamin A precursor). Describe how it differs from conventional rice and assess its potential to reduce vitamin A deficiency.Show worked solution →
- 1 mark - the genetic change
- Golden rice contains transgenes (genes from maize and a soil bacterium) that drive a beta-carotene biosynthesis pathway in the rice endosperm, which conventional rice lacks; the grain turns yellow.
- 1 mark - the intended benefit
- Beta-carotene is a precursor of vitamin A; vitamin A deficiency causes preventable blindness and immune impairment, especially in children in rice-dependent populations.
- 1-2 marks - assessment of potential
- Strengths: it delivers vitamin A through a staple already eaten daily, reaching populations where supplements and dietary diversification have failed for decades; it was approved in the Philippines in 2021, indicating regulators judge it safe. Limitations: the quantity of rice eaten and the presence of dietary fats affect how much vitamin A is actually obtained; it does not address the underlying poverty.
- 1 mark - judgement
- A supported conclusion, e.g. golden rice has real potential to reduce deficiency where adopted, but works best alongside diversification and supplementation rather than as a sole solution.
"Assess" requires a judgement of value/effectiveness; a description of the technology with no judgement caps below full marks.
core4 marksRecombinant insulin replaced insulin extracted from pig and cattle pancreases. Explain two advantages of the recombinant product over the animal-derived product.Show worked solution →
Advantage 1 - immunological match (2 marks). Animal insulin differs from human insulin by one or more amino acids, so it could provoke allergic / immune reactions in some patients. Recombinant insulin is made from the human insulin gene, so it is structurally identical to human insulin and far less likely to cause an immune response (1 mark for the structural point, 1 mark for the clinical consequence).
Advantage 2 - scalable, reliable supply (2 marks). Animal insulin depended on abattoir-sourced pancreases, a limited and variable supply, with risk of contamination. Recombinant insulin is produced by bacteria cultured in bioreactors, giving a large, consistent, scalable and ethically less contentious supply independent of slaughter (1 mark for the supply limitation of animal insulin, 1 mark for the scalability of the recombinant route).
Accept other valid advantages (e.g. removal of animal-pathogen/prion concerns). Each advantage needs both the point and its justification for full marks.
exam7 marksAnalyse the social implications and ethical issues raised by the use of biotechnology, referring to at least one plant example and one animal example.Show worked solution →
"Analyse" requires you to draw out and relate the implications - identify components and show how they connect to society and ethics - not merely list them. Full marks need at least one plant and one animal example, several distinct implications, and balanced treatment of benefits against concerns.
- Plant example (2-3 marks)
- Bt cotton / golden rice. Social benefits: higher yields, reduced pesticide exposure for farm workers, and in the case of golden rice the potential to reduce vitamin A deficiency in poor populations. Ethical / social concerns: intellectual property - patented seed concentrates control with a few corporations and can restrict seed-saving by subsistence farmers; environmental ethics - gene flow to wild relatives and selection for resistant pests; access equity - the people who most need golden rice may least afford the surrounding agricultural inputs. Relate these: the same technology that lifts yield also shifts economic power and risk onto growers and ecosystems.
- Animal example (2-3 marks)
- Recombinant insulin (transformed bacteria) or cloned/transgenic livestock (e.g. SCNT, Dolly). Social benefits: recombinant insulin gives a cheaper, scalable, slaughter-free, immunologically safe medicine, extending and improving the lives of people with diabetes; cloning can propagate elite breeding animals. Ethical concerns: animal welfare - cloned and transgenic animals show higher rates of developmental abnormality; consent and "playing God" objections to engineering whole animals; dual use - gene drives could deliberately suppress or eradicate a species. Relate these: medical biotechnology is widely accepted because the organism is a contained microbe and the product is purified, whereas engineering whole sentient animals triggers stronger welfare and moral objections.
- Analysis and judgement (1-2 marks)
- Draw the threads together: biotechnology's implications depend on what is modified and who bears the risk/benefit - a contained microbe making medicine is judged differently from a released crop or a cloned mammal. A strong answer reaches a balanced position, e.g. that the technologies are broadly beneficial but require regulation, equitable access and welfare safeguards. Listing implications without relating them to society/ethics, or omitting either the plant or the animal example, caps the mark.
exam6 marksEvaluate the use of recombinant DNA technology in medicine, using a named example to support your judgement.Show worked solution →
"Evaluate" requires a reasoned judgement weighing benefits against limitations, anchored to a named example.
- The technology and example (2 marks)
- Recombinant DNA technology cuts a human gene (e.g. the insulin gene) and inserts it into a plasmid vector, which transforms E. coli; the bacteria express the human protein, which is cultured in bioreactors and purified as a medicine (recombinant insulin / Humulin, 1982, the first recombinant drug). Recombinant vaccines (hepatitis B) and gene therapies (Luxturna, Zolgensma) are further examples.
- Benefits (1-2 marks)
- Produces immunologically identical, contamination-free human proteins at large scale and lower cost; removes dependence on animal or cadaver sources; enables treatments for previously untreatable genetic diseases (gene therapy), raising life expectancy and quality of life.
- Limitations (1-2 marks)
- High development cost and patents keep some products (e.g. million-dollar gene therapies) out of reach for many patients globally (access inequity); some applications carry safety/long-term-effect uncertainty; germline editing raises consent issues for future generations.
- Judgement (1 mark)
- A supported conclusion, e.g. recombinant DNA technology has been strongly beneficial in medicine - insulin alone has transformed diabetes care - but its benefits must be weighed against cost and equitable access. An answer that omits the judgement, or gives no named example, caps below full marks.