Genetically Engineered Corn
An insect pest
Whenever a new technique is developed in science, people immediately begin asking, how can this be applied to solve human problems? In the case of genetic engineering, a logical application was to make new strains of farm crops resistant to diseases and pests and able to grow in unfavorable conditions.
Farmers who grew corn had long battled an insect pest known as the European corn borer. This insect is a major destructive force working against farmers trying to get the best yields from their corn crops. Therefore, the corn borer was a natural target for scientists to try to eradicate using genetic engineering.
Explore the use of genetic engineering to battle the European corn borer. Click on the link below to read the Grolier Multimedia Encyclopedia™ article “Genetic Engineering.” Read the final paragraph of the “Agricultural Uses” section of the article. Then answer the following questions.
- What type of organism is Bacillus thuringiensis?
- What is Bt toxin and how does it affect insects?
- What did biologists do with the gene for Bt toxin and why?
- Have farmers planted much engineered corn?
Click on the Show Answer button to check your answers.
- a type of bacteria
- Bt toxin is a molecule produced by Bacillus thuringiensis. Bt toxin kills insects if they ingest it.
- They inserted the gene for Bt toxin into corn to kill insect pests that destroy corn crops.
- Yes. In 2006, more than 60% of the corn planted was engineered.
Bt Corn and Monarch Butterflies
A monarch caterpillar
Genetic engineering research proved successful in ridding corn of insect pests through the development of Bt corn. However, researchers at Cornell University had concerns about possible unintended consequences of the engineered corn. They wondered if the corn might kill insects that were not pests but lived in the same area as the corn. The scientists raised the question: Could Bt corn harm monarch butterflies?
Learn how Cornell University scientists tested Bt corn’s effects on monarch butterflies. Access the “Killer Corn” EBSCOhost databases article using the directions below. Read the article. Then answer the following questions.
- If monarch caterpillars do not eat corn, how would they come into contact with Bt toxin?
- What experiment did the Cornell scientists carry out?
- What were the results of the experiment?
- What does this suggest about a potential problem concerning Bt corn?
Click on the link below to access the EBSCOhost databases. Follow the directions below to access the article.
- Select EBSCOhost Research Databases.
- Check the box for Select all and click on the Continue button.
- Type "killer corn" in the search box, and click on the Search button.
- Select the article “Killer Corn” by Sharon Guynup.
Click on the Show Answer button to check your answers. Answers:
- The monarch caterpillars eat milkweed plants. Scientists were concerned that pollen from the Bt corn might land on milkweed plants and be eaten along with the milkweed.
- They fed monarch caterpillars with milkweed dusted by Bt corn pollen and with normal corn pollen.
- Half of the caterpillars feeding on the Bt corn pollen died, while all caterpillars feeding on normal corn pollen lived.
- The monarch butterfly population may be in danger if Bt corn is planted in large quantities in the areas where it lives.