Question

In the DNA double helix how are the two strands of DNA held together

Answer 1

Hydrogen bonds between the base pairs hold the two strands of DNA together.

Step-by-step explanation:

Watson and Crick used Rosalind Franklin's important work imaging DNA molecules to make several observations.

Answer 2

H bonding between the nitrogen bases of the two strands

Step-by-step explanation:

There are two types of nitrogen bases found in DNA: purines and pyrimidines.

Purines are Adenine and Guanine.

Pyrimidines are Thyamine and Cytosine.

Adenine of one strand bonds with Thyamine of other strand by 2 hydrogen bonds. Likewise, guanine and cytosine of opposite strands bind by 3 hydrogen bonds. In this way two strands of DNA are held together.