12.6 Consider This: Checking All Bases

The structural features of a DNA molecule are more apparent if you can look at a three-dimensional (3-D) representation.: To view the DNA molecule, you will need to install CHIME.

1. How is a 3-D structure of DNA shown at that site similar to the one shown in the text? How is it different?
2. Look carefully at the structures of the four bases that comprise DNA. What are their structural common features? How do they differ?
3. Look again at the large DNA molecule. Can you find the bases? How are they aligned?

12.7 Consider This: Discovering Rosalind Franklin

In 1958, Rosalind Franklin died an untimely death from ovarian cancer at age 37. Thus, she did not live long enough to add her own account to the history that was written (and rewritten) about the discovery of DNA. Because her work was long minimized or ignored, some historians now assert that both DNA and Rosalind Franklin were discovered. To set the record straight, several excellent biographies of Franklin are now available. You can find reviews of these books as well as other accounts of her life on the Web by searching for Rosalind Franklin. What were her contributions to the structure of DNA? Why was her work not given full credit during her time? What questions would you ask her if you could interview her?

12.12 Consider This: Where Does Insulin Come From?

If a person must take insulin daily, how would that person determine the source of the insulin? Does the source make a difference in how the insulin acts in the body? Use the resources of the Web or consult a pharmacist to answer these questions.

12.19 Consider This: Where in the World Is BGH?

In 1985, the U.S. FDA approved the use of BGH in cows for boosting milk production. Although regulatory agencies around the world have reached the same conclusion, the debate over whether BGH should be used this way is far from over. Search the Web for "bovine growth hormone" (or its synonyms "bovine somatotropin" or "BST") to check the current situation and report the arguments on both sides. If you can, document the situation in countries other than the United States.

12.21 Consider This: The Human Genome Project

In 2000, the Human Genome Project completed the sequence for all of the base pairs at least to the level of a "rough draft." What are likely to be some of the problems with the early version? Are there any ways to know if there were mistakes? In 2001, scientists completed the genetic maps of a weed, the thale cress plant, and the bacterium that causes cholera. Are any of these accomplishments useful to the sequence data for humans?

12.22 Consider This: The "Frankenfood" Frenzy

The European Union is pushing for stricter controls over the importation of genetically modified foods. Opposition to GM foods was a major theme of American protesters at the 2000 World Trade Organization meeting in Seattle and IMF/World Bank meetings in Washington, DC.

Recent tactics by transgenic food opponents have included a class-action suit against Monsanto, a producer of seeds. The Food and Drug Administration announced a new initiative to engage the public about bioengineered products. Search for and describe articles about recent developments in the "Frakenfood" controversy. Try to establish the bases for concerns by critics, and any evidence refuting them.