Evaluating Genetic Engineering and Selective Breeding

1. 1 State [2 marks]

   State two benefits of genetic engineering in medicine.

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   Model answer

   Any two from: it makes cheap, safe medicines such as insulin in large amounts; gene therapy can treat inherited disorders; it makes products such as growth hormone.

   Mark scheme

   • First benefit — 1 mark
   • Second benefit — 1 mark
2. 2 State [2 marks]

   State one practical issue and one ethical issue with genetic engineering.

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   Model answer

   A practical issue is that pests may become resistant or genes may spread to wild plants. An ethical issue is that some people think it is wrong to interfere with the genes of living things, or concern about patents.

   Mark scheme

   • Practical issue — 1 mark
   • Ethical issue — 1 mark
3. 3 Compare [4 marks]

   Compare genetic engineering and selective breeding in agriculture.

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   Model answer

   Selective breeding uses the genes that are already in the species and takes many generations, whereas genetic engineering can add a gene from any species in one generation. Selective breeding is cheaper, and genetic engineering is more expensive. Selective breeding can cause inbreeding and reduced variation, and genetic engineering raises concerns about safety and the environment.

   Mark scheme

   • Genes: same species / any species — 1 mark
   • Many generations / one generation — 1 mark
   • Cheaper / more expensive — 1 mark
   • A different concern for each — 1 mark
4. 4 Explain [4 marks]

   Explain why some people object to the use of genetic engineering in agriculture.

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   Model answer

   Some people think that it is wrong to interfere with the genes of living things. There are also worries that modified genes could spread to wild plants and harm other organisms, and that the long-term effects on health are unknown. Some are concerned that large companies own the seed, so that farmers become dependent on them.

   Mark scheme

   • Interfering with genes is wrong — 1 mark
   • Genes could spread to wild plants — 1 mark
   • Long-term effects not known — 1 mark
   • Patents and control by companies — 1 mark
5. 5 Evaluate [6 marks]

   Evaluate the use of genetic engineering to produce golden rice, which makes beta-carotene.

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   Model answer

   Golden rice makes beta-carotene, which the body can change into vitamin A, so it could prevent the blindness and deaths caused by vitamin A deficiency, especially in children in countries where rice is the main food. It could be grown by poor farmers if the seed is free. However, some people are concerned about the safety of GM food and the effect of the gene on the environment, and about the control of the seed by companies. Others say that it would be better to improve diets in other ways. The scientific evidence so far has shown no harm, so on balance the benefits seem to outweigh the risks, as long as it is tested and regulated properly.

   Mark scheme

   • Prevents vitamin A deficiency — 1 mark
   • Helps poor people / main food — 1 mark
   • Concern about safety or environment — 1 mark
   • Concern about control by companies / alternatives — 1 mark
   • No evidence of harm — 1 mark
   • A reasoned conclusion — 1 mark
6. 6 Evaluate [6 marks]

   A farmer is deciding whether to buy GM seed or to use conventional seed from selective breeding. Evaluate the two options.

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   Model answer

   GM seed may give a higher yield, because it resists pests, and it may reduce the cost of spraying, which would increase the farmer's profit and help the environment. But the seed is more expensive, and has to be bought new each year, and pests may become resistant. Conventional seed from selective breeding is cheaper and the farmer can save seed, and there is little public concern. However, the yield may be lower, and the crop may need more pesticide, and the plants may be less resistant. The best choice depends on the cost, the amount of pest damage and the market, but a mix of options may reduce risk.

   Mark scheme

   • GM: higher yield / less spraying — 1 mark
   • GM: cost of seed / resistance — 1 mark
   • Conventional: cheaper, save seed — 1 mark
   • Conventional: lower yield, more pesticide — 1 mark
   • Environmental point — 1 mark
   • A reasoned conclusion — 1 mark

Quick check

1. 1

   What should an evaluation include?

   1. AOnly benefits
   2. BOnly risks
   3. CBenefits, risks and a conclusion
   4. DA list of definitions
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   C: Benefits, risks and a conclusion

   An evaluation weighs up benefits and drawbacks, and ends with a justified conclusion.

2. 2

   Which is a benefit of genetic engineering in medicine?

   1. ACheap, safe insulin in large amounts
   2. BCures for all diseases
   3. CNo risk at all
   4. DReduced variation
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   A: Cheap, safe insulin in large amounts

   GM bacteria can make large amounts of cheap, safe insulin.

3. 3

   Which is an ethical issue about genetic engineering?

   1. AThe yield of the crop
   2. BThe cost of seed per tonne
   3. CThe size of the fermenter
   4. DWhether it is right to interfere with genes
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   D: Whether it is right to interfere with genes

   Some people think that it is wrong to change the genes of living things.

4. 4

   Which is a risk of selective breeding?

   1. AIt adds genes from other species
   2. BIt can cause inbreeding and reduced variation
   3. CIt is very fast
   4. DIt is very expensive
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   B: It can cause inbreeding and reduced variation

   Inbreeding can cause genetic disorders, and reduced variation makes populations vulnerable.

5. 5

   Which method can move a gene from one species to another?

   1. AGenetic engineering
   2. BSelective breeding
   3. CNatural selection
   4. DTissue culture alone
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   A: Genetic engineering

   Only genetic engineering can add a gene from a different species.

6. 6

   Which is a concern about patents on GM seed?

   1. AThe seed never grows
   2. BThe seed is too cheap
   3. CFarmers may depend on the companies for seed
   4. DThe seed contains no genes
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   C: Farmers may depend on the companies for seed

   Farmers may depend on a company, and have to buy new seed each year.

7. 7

   Why is selective breeding usually less controversial than genetic engineering?

   1. AIt is faster
   2. BIt is more precise
   3. CIt uses GM organisms
   4. DIt uses natural variation within a species
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   D: It uses natural variation within a species

   It uses the natural variation in a species, and does not move genes between species.

8. 8

   Which statement is a good conclusion to an evaluation?

   1. AGM crops exist
   2. BOn balance the benefits outweigh the risks because yields are higher, as long as there is regulation
   3. CGenes are made of DNA
   4. DSelective breeding takes many generations
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   B: On balance the benefits outweigh the risks because yields are higher, as long as there is regulation

   A conclusion states a judgement and gives a reason for it, based on the evidence.

9. 9

   A new GM crop increases yield by 20% but may harm wild plants. How should a scientist decide whether to approve it?

   1. AWeigh the benefits and risks using evidence and testing
   2. BApprove it because yield is higher
   3. CReject it because genes are involved
   4. DAsk only the company that made it
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   A: Weigh the benefits and risks using evidence and testing

   Decisions should weigh the evidence of benefits against the possible risks, test the crop carefully, and consider ethical views.