Final answer:
The type of bond between nitrogen bases of DNA is hydrogen bond. Each hydrogen bond is weak but they add up to a strong overall effect in a DNA molecule. This allows for the DNA to exist in its double helix structure, and for it to be replicated accurately.
Step-by-step explanation:
The chemical bond present between nitrogen bases of DNA is known as a Hydrogen bond. DNA structure is a double helix made up of two strands running in opposite directions. Each strand is formed by four nitrogen bases: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G). Adenine always pairs with Thymine by two hydrogen bonds, and Cytosine always pairs with Guanine by three hydrogen bonds.
Hydrogen bonds are weak bonds but when many hydrogen bonds are together as in a DNA molecule, they can be very strong. These hydrogen bonds enable the DNA to exist in its double helix structure and they are easily broken and reformed during replication, allowing the DNA to be copied precisely.
Learn more about Hydrogen bonds in DNA