Hydrogen bonds link the bases together in DNA and RNA base pairs.

Quick Scoop: What type of bond links bases together?

When people ask “what type of bond links bases together,” they are almost always talking about the nitrogenous bases in the DNA double helix (A with T, and C with G) or in RNA (A with U, and C with G). These paired bases are held together by hydrogen bonds, which are relatively weak intermolecular attractions, not strong covalent links.

  • In DNA:
    • Adenine (A) pairs with thymine (T) via 2 hydrogen bonds.
* Guanine (G) pairs with cytosine (C) via 3 hydrogen bonds.
  • In RNA:
    • Adenine (A) pairs with uracil (U), also via hydrogen bonds.

These hydrogen bonds are just strong enough to hold the two strands together, but weak enough that the strands can separate during processes like DNA replication and transcription.

Extra context (in case your teacher asks “which bonds where?”)

To avoid a classic exam trick, it helps to distinguish two different “holding together” ideas in DNA:

  1. Between bases across the two strands (your question):
    • Linked by hydrogen bonds (A–T and G–C pairs).
  1. Along each strand (backbone of DNA):
    • Bases are attached to sugars; sugars are linked to phosphates.
    • These are covalent bonds (specifically phosphodiester bonds) and they strongly hold the strand itself together.

So if the question is specifically “what type of bond links bases together in base pairs?” the expected answer is hydrogen bonds.

Information gathered from public forums or data available on the internet and portrayed here.