Avery's experiment demonstrated that the destruction of DNA led to the loss of the ability to transform R cells into S cells, highlighting DNA as the carrier of heritable information. Here option C is correct.
Avery's experiment, conducted in 1944 along with colleagues Colin MacLeod and Maclyn McCarty, aimed to identify the substance responsible for transforming harmless R strain bacteria into deadly S strain bacteria in the context of pneumococcal bacteria.
The experiment involved treating heat-killed S strain bacteria with enzymes that specifically destroyed different macromolecules, including proteins, RNA, and DNA.
The key observation supporting the idea that DNA transfers heritable information was the result that when the enzyme destroyed DNA, the ability to transform R cells into S cells was lost.
This result strongly suggested that DNA, and not proteins or RNA, carried the heritable information responsible for the transformation. The absence of S strain bacteria in samples with intact DNA indicated that the genetic material in DNA was essential for the transmission of heritable traits, supporting the role of DNA as the carrier of genetic information. Here option C is correct.
Complete question:
He looked for living S bacterial cells in each of the three batches that contained living R cells. How did the results of Avery's experiment show that DNA transfers heritable information?
A. The samples with destroyed DNA did not produce living S strain bacteria.
B. Living S cells did not appear in samples that still had intact RNA.
C. In the samples with intact DNA, no S strain bacteria were found.
D. Living S cells appeared only in the samples with destroyed proteins