The genetic material must store genetic information and accurately transmit that information from parents to offspring, generation after generation: the phenotypic function, gene expression. The genetic material must control the development of the phenotype of the organism. That is, the genetic material must dictate the growth of the organism from the single- celled zygote to the mature adult: the evolutionary function, mutation. Key points: the genetic material must perform three essential functions: replication, gene expression, and mutation. Proof that genetic information is stored in dna. Proof that dna mediates transformation: chapter 8 something from the heat-killed cells the transforming principle had converted the live type iir cells to type iiis. Iiis cells required to transform type iir cells to type iiis: the most definitive experiments involved the use of enzymes that degrade. Proof that rna stores the genetic information in some viruses: many viruses contain rna and proteins, but no dna.