DNA is the genetic material. Put simply, DNA holds the plan for the development of the Cell or Organism. It gives the instructions. The characteristics that a cell or organism inherits are based on the DNA. Whether the person is tall or short, whether the peas are wrinkled to round, whether the flower is pink or red: it all depends on the DNA.
Proof that DNA is the genetic material:
The experiment of Frederick Griffith, which took place in 1928, was an essential first step to prooving that DNA is the genetic material. Still, it was thanks to Colin MacLeod, Oswald Avery, and Maclyn McCarty that it was finally proven that DNA is in fact the genetic material. They were able to come up with a way for isolating DNA, which wasn't perfect as there were some traces of RNA and Proteins, but it is plausible to say that the DNA was almost pure. So, they isolated almost pure DNA from smooth Streptococcus pneumoniae and added it to rough Streptococcus pneumoniae. After that Transformation took place. What was interesting and what proved that DNA is the genetic material was that, when treated with substances that destroy RNA and protein, the transformation was not altered. When treated with substance that target DNA, though, the transforming activity was eliminated .
- ↑ L. Hartl D, W. Jones E. Genetics: Analysis of Genes and Genomes. 7th ed. Sudbury: Jones and Bartlett Publishers; 2009.