Question

Griffith's studies were instrumental in the discovery of DNA as the genetic material because his experiments demonstrated

A. that DNA is made of nucleotides
B. the existence of bacterial viruses
C. transformation in bacteria

Answer 1

In the 1920s, Griffith discovered that a non-virulent strain could become virulent when mixed with heat-killed virulent bacteria, hinting at a 'transforming principle.' Avery, MacLeod, and McCarty later identified DNA as this transforming substance, affirming DNA's role as genetic material, supported by Hershey and Chase's subsequent research.

Step-by-step explanation:

In the 1920s, Griffith's work with Streptococcus pneumoniae strains revealed that a non-virulent R (rough) strain could become virulent when mixed with the heat-killed virulent S (smooth) strain. This indicated that some 'transforming principle' from the S strain changed the R strain's properties. Although Griffith did not identify this principle as DNA, his findings laid the foundation for subsequent research by Avery, MacLeod, and McCarty, who proved that DNA is required for transformation. Their work, together with later studies by Hershey and Chase, established DNA as the genetic material.