Whereas old dependency theory was Marxist in presentation, but nationalist in orientation, seeking to combine a theory of class struggle with a nationalist âthird worldistâ ideology, the new dependency theory is institutionalist in its analysis and political orientation.
Griffith concluded that the type II-R had been transformed into the lethal III-S strain by a transforming principle that was somehow part of the dead III-S strain bacteria. Today, we know that the transforming principle Griffith observed was the DNA of the III-s strain bacteria. While the bacteria had been killed, the DNA had survived the heating process and was taken up by the II-R strain bacteria. The III-S strain DNA contains the genes that form the protective polysaccharide capsule.
The team added extract enzymes known to break down proteins, the extract still transformed the R bacteria to the S form. Transformation failed to occur when they added an enzyme that destroys DNA How did Avery and his group identify the transforming principle? In their first experiment bacteria was infected with phages that had radioactive sulfur atoms in their protein molecules and when they separated the proteins from the bacteria they found no radioactivity on the bacteria