Final answer:
The Avery-MacLeod-McCarty experiment built on Frederick Griffith's demonstration of bacterial transformation, which identified DNA as the genetic material responsible for this process. They proved that destroying DNA in heat-killed virulent S strain bacteria prevented transformation of the non-virulent R strain.
Step-by-step explanation:
Avery-MacLeod-McCarty Experiment
The experiment that Avery, MacLeod, and McCarty piggybacked off of was Frederick Griffith's 1928 experiment, which demonstrated the phenomenon of transformation. Griffith's work was crucial in understanding that a 'transforming principle' could transfer genetic information from one strain of bacteria (the virulent S strain) to a different, non-virulent strain (the R strain).
In their follow-up work, Avery and his colleagues aimed to identify the chemical nature of the transforming principle. They systematically destroyed different components (proteins, carbohydrates, lipids, RNA, and DNA) of the heat-killed virulent S strain bacteria and tested if the non-virulent R strain could still be transformed. Their experiments showed that only when DNA was destroyed, the transformation did not occur. This indicated that DNA was the genetic material responsible for transformation, therefore identifying DNA as the key component for hereditary transfer.
The discovery made by Avery, MacLeod, and McCarty encountered initial skepticism from the scientific community, which was inclined to view proteins as the genetic material due to their greater complexity and functional diversity. However, their work laid the foundation for future research that conclusively established DNA as the carrier of genetic information.