Chapter 11: Inferences
Lab Activity 55: Inferences in Texts and Visuals tbskils_small.gif
 

tbskils.gifObjective
To make inferences about a selection from a textbook.


arrow.gifStep 2: Read the following selection from a college biology textbook and then answer the questions that follow.

Case Study: Food Fight

1     The spring sun shines brightly on the Mississippi countryside as a tractor crawls slowly across a field. A farmer is planting his soybean crop. But some critics see the farmer's seemingly harmless activity as extremely dangerous. In this view, the farmer's activity threatens our health, our food supply, and the environment. According to writer Jeremy Rifkin, the farmer and others like him are "spreading chaos throughout the biological world, drowning out the ancient language of creation." Around the world, impassioned protestors demand protection from the farmer's crops.

2     Why does something as ordinary as farming inspire such intense opposition? Because more and more farmers are growing genetically altered, bio-engineered crops. These genetically modified foods have been singled out for especially harsh attack by critics of biotechnology, in part because, unlike most nonagricultural applications of biotechnology, genetic engineering in agriculture is already widespread and common; its products are used by farmers everywhere. You've almost certainly consumed a bioengineered food; such foods are widely sold in the United States and no law requires that they be specially labeled.

3     Agricultural biotechnology is based on the introduction of foreign genes into crop plants. The purpose of such gene transfers is often to confer resistance to a disease, pest, or herbicide. For example, farmers are now planting corn, cotton, and potatoes that contain a gene that helps the plants repel insect pests, reducing the farmers' need to apply pesticides. New, bio-engineered strains of squash, potatoes, and tomatoes resist infection by viral diseases. Cotton, corn, soybeans, and sugar beets have been altered so that they are resistant to particular herbicides; farmers who grow these altered plants can use the herbicides to control weeds without worrying that the herbicides will kill the crops. Other fruits, vegetables, and even farm animals have been genetically engineered for improved yields, better nutritive value, or better resistance to the stress of shipping and handling.

4     The genes that are used to confer desirable qualities on crops are typically drawn from fungi or bacteria.

—Audersirk, Andersirk, and Byers, Life on Earth, 3rd ed., p. 187.


      4. "According to writer Jeremy Rifkin, the farmer and others like him are ‘spreading chaos throughout the biological world, drowning out the ancient language of creation.’"

From this statement, the reader would conclude that bioengineering  

 
 
 
 
      5. Which is not a detail from paragraph 2 that would help the reader conclude why critics are condemning bioengineering? 

 
 
 
 
      6. The author suggests that bioengineering is already being done for all of the following reasons except  

 
 
 
 
      7. Genes that are used to provide desirable traits in crops are typically drawn from  

 
 
 
 
     

Case Study Revisited

1     To many people, the improvements gained through agricultural biotechnology represent advances that are crucial to human well-being. Robert Shapiro, a former executive of Monsanto, a company that sells bioengineered seeds, believes technology is necessary to feed a growing population. He asks, "How are you going to feed 10 to 12 billion people a decent diet when in fact there will not only be no more acreage available to produce that food, there may very well be less?" To Shapiro, the answer is obvious. But critics of transgenic foods are equally certain that the potential benefits of biotechnology are dwarfed by the risks.

2     The critics worry that introducing new genes to food may also inadvertently introduce new substances that are toxic or that cause allergic reactions. They are concerned that herbicide-resistant crops encourage farmers to use excessive amounts of dangerous herbicides. They believe that farmers will come to regret their increasing dependence on the large corporations that produce bioengineered seeds. They also fear that bioengineered organisms could escape from farm fields, establish a foothold in the wild, and disrupt ecosystems.

—Audesirk, Audesirk, and Byers, Life on Earth, 3rd ed., p. 202

8. The topic of this selection is  

 
 
 
 
      9. From the information in paragraph 1, which statement from the list best states an accurate conclusion? 

 
 
 
 
      10. From the information in paragraph 2, you could accurately conclude that  

 
 
 
 





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