One of the central public debates of the coming years may well be over what we should eat for dinner. Or more specifically, whether we should be eating (and growing and selling) genetically modified plants.

One side claims genetically modified plants can end world hunger and do away with pesticides. The other side protests that the risks are still unclear, speaks of "frankenfoods," and warns of superpests.

Who's right? The jury is still out.  

What is clear is that we're already eating these plants. Estimates suggest that at least 60 percent of the processed food we eat contains genetically modified ingredients. By the year 2000 about 60 percent of the soybean crop and 25 percent of the corn crop in the United States was genetically modified. Although government agencies responsible for regulating food and agriculture assure the public that these bioengineered foods are safe, critics claim the risks have not yet been properly assessed. This backgrounder presents both sides of the controversy surrounding genetically modified plants.

What are GMOs?
Genetic modification involves inserting a gene from one organism into another. The result is considered a genetically modified organism (GMO). The transferred gene, known as a transgene, carries the instructions for making a protein, as all genes do. These proteins control the organism's biological processes and determine its characteristics. The purpose of genetic modification is to transfer a gene responsible for a particular desirable trait to another organism so that it will then share that trait.

Although the term GMO can refer to a genetically modified plant or animal, it is used most often in discussing plants. Genetically modified plants are sometimes described as bioengineered or transgenic.

Scientists have traditionally bred plants for desirable traits. But conventional breeding is slower and far less accurate than genetic modification in producing the desired characteristics. Nearly 150 years ago Austrian monk Gregor Mendel laid the foundation for modern genetics through his experiments in cross-breeding pea plants. Genetically modified plants were first created in the early 1980s.

These articles from Encarta Encyclopedia provide more information about genetic processes and techniques:

• Heredity explains the processes by which biological traits are transmitted through genes. 
• Genetics explains the techniques scientists have developed for rearranging and transferring genetic material.
• Genetic Engineering explains the principles of selective breeding and the techniques of gene splicing. 
• Gene discusses the basic unit of heredity that determines an organism's physical characteristics. Genes are the "software" for genetic modification. 
• Clone describes organisms that are identical genetic copies of other organisms.

The following Encarta Encyclopedia articles and special reports are available to those with access to MSN Encarta Premium:

• The Debate Over Genetically Modified Food explores some of the issues and controversies related to genetic modification of plants.
• "Does Genetic Engineering Benefit Society?" presents arguments for and against genetic engineering of plants and animals. 
• Engineering Disease Resistance reports on progress at introducing disease-resistant genes in high-yield rice.
• Plant Propagation discusses conventional breeding methods as well as genetic engineering.
• Plant Breeding explains how the practical application of genetic principles can be used to develop improved strains of plants.