PASSAGE 1: Genetically Engineered Crops
By Tony Esplanade
More than 11,000 years ago, humans began to alter plants. Farmers picked plants with certain traits and bred them to make new types of plants. In time, farmers cultivated plants that differed from plants that grew in the wild. Here is one example. About 10,000 years ago in an area that would become Mexico, farmers chose a type of grass called the teosinte plant. The plant produced grains of starch stored in small seedpods. Over time, farmers picked and grew plants that made more starch. The end result was the corn plant.
In modern times, scientists alter plants by genetic engineering. The word “engineering” refers to the science of designing and constructing things.
Genetic engineering uses science to isolate, analyze, and modify genes. Plants that have altered genes are called genetically engineered (GE) plants. U.S. farmers planted the first large-scale GE crop in 1996. Since then, people have argued about whether GE crops are harmful or helpful.
Those who oppose GE crops argue that the plants pose possible risks to human health and the environment. One argument against GE crops is that changing a plant’s genes might accidentally cause the plant to produce a toxin that would harm humans. After almost 20 years of experience, this problem has not occurred.
Another argument against GE crops is that GE plants may spread beyond their fields. GE plants that grow in the wild might breed to produce new types of plants. This problem has happened. The canola plant produces seeds that are used to create canola oil. In 2010, scientists showed that GE canola plants were growing outside of their original fields. They also found evidence that the plants bred in the wild to produce new types of GE canola plants. The study highlighted the need to restrict GE plants inside their fields with chemicals. These chemicals are not only costly for farmers but also harmful to the environment.
Other types of GE crops provide unique advantages to farmers. One type of GE crop can resist viruses that cause diseases. As an example, a serious outbreak of ringspot virus threatened Hawaii’s papaya crops during the 1990s. Today, most papayas sold in Hawaii are GE plants that resist the virus. Another type of GE crop is designed to enable farmers to decrease the amounts of chemical herbicides used to kill weeds. Yet another type of GE crop is designed to enable plants to survive under harsh conditions. For example, corn is a widely grown staple crop in Africa. African farmers often face the problem of drought. One type of GE corn tolerates these dry conditions.
2. According to Passage 1, what is the concern regarding genetically engineered foods?
A Plants with altered genes were first planted in 1996 in the first large-scale GE crop.
B In Mexico, the teosinte grass produced grains of starch that eventually created the corn plant.
C Farmers can use GE crops that resist viruses that may cause disease.
D There are possible risks to the environment and to people’s health.