Answer:
Nitrogenous Bases.
Step-by-step explanation:
Adenine, Thymine, Guanine and Cytosine are the four number of nitrogenous bases that are found in DNA. These are the chemical units which form DNA and further their specific sequences become the unit of heredity which is called gene. All the information that lies in DNA is due to the different sequence of these nitrogenous bases. These bases are arranged in different manner in the DNA. Some long or short sequences of the bases are specific and perform specific functions in our body. These are the genes.