Distance between two adjacent nitrogenous bases of DNA is

Options

A. `2.4 dotA`
B. `3.4 dotA`
C. `24 dotA`
D. `34 dotA`

Answer

To determine the distance between two adjacent nitrogenous bases in DNA, we can follow these steps:

1. **Understanding DNA Structure**: DNA is structured as a double helix, with nitrogenous bases paired in the center. Each complete turn of the helix is referred to as a "pitch."

2. **Pitch of DNA**: The pitch of the DNA helix is approximately 34 angstroms (Å), which is equivalent to 34 x 10^-10 meters. This distance encompasses the entire length of one complete turn of the helix.

3. **Number of Base Pairs per Pitch**: In one complete pitch of DNA, there are about 10 base pairs. This means that each base pair contributes to the overall distance of the pitch.

4. **Calculating Distance Between Adjacent Bases**: To find the distance between two adjacent nitrogenous bases, we divide the total distance of the pitch by the number of base pairs:
\[ \text{Distance between adjacent bases} = \frac{\text{Pitch}}{\text{Number of base pairs}} = \frac{34 \, \text{Å}}{10} = 3.4 \, \text{Å} \]

5. **Conclusion**: Therefore, the distance between two adjacent nitrogenous bases in DNA is 3.4 angstroms.

### Final Answer:
The distance between two adjacent nitrogenous bases of DNA is **3.4 angstroms**.