History of DNA Discovery CH 11 Section 1

History of DNA Discovery ► British biologist Frederick Griffith discovered “transforming factor” when doing an experiment w/ bacterial pneumonia on mice in (p. 226) British biologist Frederick Griffith discovered “transforming factor” when doing an experiment w/ bacterial pneumonia on mice in (p. 226) British biologist Frederick Griffith discovered “transforming factor” when doing an experiment w/ bacterial pneumonia on mice in (p. 226) ► American scientist Oswald Avery conducted experiments that showed DNA had to be the “transforming factor” (p. 227) American scientist Oswald Avery conducted experiments that showed DNA had to be the “transforming factor” (p. 227) American scientist Oswald Avery conducted experiments that showed DNA had to be the “transforming factor” (p. 227) ► Alfred Hershey & Martha Chase conducted a series of experiments using bacteriphages to help solidify that DNA must carry genetic information. (p. 228) Alfred Hershey & Martha Chase conducted a series of experiments using bacteriphages to help solidify that DNA must carry genetic information. (p. 228) Alfred Hershey & Martha Chase conducted a series of experiments using bacteriphages to help solidify that DNA must carry genetic information. (p. 228)

► Griffith showed that although a deadly strain of bacteria could be made harmless by heating it, some factor in that strain is still able to change other harmless bacteria into deadly ones. He called this the "transforming factor."

► Hershey and Chase offered further evidence that DNA, not proteins, is the genetic material. Only the DNA of the old generation of viruses is incorporated into the new generation.

Concept Check How did Griffith's experiments indicate the presence of a "transforming factor" in bacteria? 2. What did Avery's experiments add to the knowledge gained from Griffith's experiments? 3. Describe the experimental design that allowed Hershey and Chase to distinguish between the two options for genetic material.