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:
1. L. Hartl D, W. Jones E. Genetics: Analysis of Genes and Genomes. 7th ed. Sudbury: Jones and Bartlett Publishers; 2009.