Both the arms of DNA helix are joined with ..... bonds.

Explanation

To answer the question "Both the arms of DNA helix are joined with ..... bonds," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding DNA Structure**: DNA is structured as a double helix, which consists of two long strands that twist around each other. Each strand is made up of a sugar-phosphate backbone and nitrogenous bases.

2. **Identifying the Bonds**: The two strands of DNA are held together by interactions between the nitrogenous bases that are attached to the sugar-phosphate backbone.

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