GM Plants & Food Production (Edexcel IGCSE Biology (Modular))
Revision Note
Genetic Engineering: Crops
Genetically modified plants are plants that have had foreign DNA inserted into their genome
This is usually done to improve food production in some way
Crops can be genetically modified (they are known as GM crops)
Crop plants, such as wheat and maize, have been genetically modified to contain a gene from a bacterium that produces a poison that kills insects, making them resistant to insect pests such as caterpillars. This can improve crop yields
Crop plants have also been genetically modified to make them resistant to certain herbicides (chemicals that kill plants), meaning that when the herbicide is sprayed on the crop it only kills weeds and does not affect the crop plant
Some crops have been genetically modified to produce additional vitamins and improved nutritional value, e.g. ‘golden rice’ contains genes from another plant and a bacterium which make the rice grains produce a chemical that is turned into vitamin A in the human body, which could help prevent deficiency diseases in certain areas of the world
Some have been genetically modified to be drought-resistant (to grow better in very dry conditions). This can also improve crop yields
Concerns about GM crops include the effect on populations of wildflowers and insects
Some people feel the effects of eating GM crops on human health have not been fully explored
Advantages & disadvantages of GM crops table
Advantages | Disadvantages |
|---|---|
Reduced use of chemicals such as herbicides and pesticides – better for the environment | Increased costs of seeds – companies that make GM seeds charge more for them to cover the cost of developing them. This can mean smaller, poorer farmers cannot compete with larger farms |
Cheaper / less time-consuming for farmers | Increased dependency on certain chemicals, such as the herbicides that crops are resistant to – often made by the same companies that produce the seed and more expensive to buy |
Increased yields from the crops as they are not competing with weeds for resources or suffering from pest damage | Risk of inserted genes being transferred to wild plants by pollination, which could reduce the usefulness of the GM crop (e.g., if weeds also gain the gene that makes them resistant to herbicide) |
| Reduced biodiversity as there are fewer plant species when herbicides have been used – this can impact insects and insect-eating birds |
| Some research has shown that plants that have had genes inserted into them do not grow as well as non-GM plants |
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