The structure of DNA resembles a twisted ladder. Which structural components form the rungs of the ladder? phosphate groups nitrogenous base pairs ribosomes

The structural components that form the rungs of the DNA ladder are the **nitrogenous base pairs**. Here's a brief explanation of the components: 1. **Phosphate groups**: These are part of the backbone of the DNA structure, along with sugar molecules, but they do not form the rungs. 2. **Nitrogenous base pairs**: These are the actual rungs of the ladder, consisting of pairs of nitrogenous bases (adenine with thymine, and cytosine with guanine) that are connected by hydrogen bonds. 3. **Ribosomes**: These are not a component of DNA; they are involved in protein synthesis and are found in the cytoplasm of cells. Thus, the correct answer is **nitrogenous base pairs**.