What type of bond holds the two strands of DNA together?

The two strands of DNA are held together primarily by hydrogen bonds, which form between the nitrogenous bases on each strand. Each base on one strand pairs specifically with a complementary base on the opposite strand; adenine pairs with thymine, and cytosine pairs with guanine. The hydrogen bonds that form between these paired bases are relatively weak compared to covalent bonds, which allows the DNA strands to separate during processes like DNA replication and transcription.

The presence of hydrogen bonds is crucial for the stability and integrity of the DNA double helix structure while enabling functionality, as the strands can easily uncoil and separate when needed. This characteristic of hydrogen bonding is fundamental to the mechanisms of genetic information transfer and the processes of life.