Genetically modified plantsSpec 5.15
Genetically modified plants can be used to improve food production. A gene for a useful characteristic is transferred into a crop plant, so the crop has that characteristic.
A well-known example is the gene from the bacterium Bacillus thuringiensis (Bt) put into crop plants. The gene codes for a toxin that kills many insect pests. The plants make the toxin themselves and so have insect resistance.
| Advantages | Disadvantages |
|---|---|
| Less crop is lost to pests, so yields are higher | Possible risk to human health, which some people worry about |
| Less insecticide needs to be sprayed, which saves money and reduces damage to other organisms | Genes may spread to wild plants, and the toxin might harm other insects |
| Crops can be given extra characteristics, such as greater nutritional value or resistance to disease | GM seeds can be expensive |
| More food can be produced for a growing population | Concerns that it is wrong or unnatural to change the genes of organisms |
Structure 'advantages and disadvantages' answers as a balanced argument. Link each point to the crop, the farmer, people or the environment.
Quick check
What is selective breeding?
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Humans choosing which organisms to breed so that desired characteristics are passed on to the next generation.
Which enzyme cuts DNA at specific sites?
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A restriction enzyme.
Which enzyme joins pieces of DNA together?
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Ligase.
What does transgenic mean?
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The transfer of genetic material from one species to a different species.
Where are GM bacteria grown to make large amounts of insulin?
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In a fermenter.