The distance between two consecutive base pairs in DNA is

Options

A. `0.34 times 10^(-9)m`
B. `3.4 times 10^(-9) m`
C. `34 times 10^(-9)m`
D. `34 times 10^(-6)m`

Answer

To solve the question regarding the distance between two consecutive base pairs in DNA, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Structure of DNA**: DNA is composed of two strands that form a double helix. Each strand consists of a sequence of nucleotides, and each nucleotide contains a base (adenine, thymine, guanine, or cytosine).

2. **Identifying Base Pairs**: In DNA, bases pair specifically (A with T and G with C). Each pair of bases forms a base pair.

3. **Pitch of the DNA Helix**: The pitch of the DNA helix refers to the distance it takes for the helix to complete one full turn. This is typically around 10 base pairs per turn.

4. **Calculating the Distance for One Turn**: The pitch length of the DNA helix is approximately 34 Ångströms (Å), which is equivalent to 3.4 nanometers (nm).

5. **Calculating Distance Between Consecutive Base Pairs**: Since there are 10 base pairs in one complete turn of the helix, the distance between two consecutive base pairs can be calculated by dividing the pitch length by the number of base pairs per turn:
\[ \text{Distance between consecutive base pairs} = \frac{\text{Pitch length}}{\text{Number of base pairs}} = \frac{34 \, \text{Å}}{10} = 3.4 \, \text{Å} \]

6. **Converting Ångströms to Nanometers**: Since 1 Ångström is equal to \(10^{-10}\) meters, we can convert 3.4 Å to nanometers:
\[ 3.4 \, \text{Å} = 3.4 \times 10^{-10} \, \text{m} = 0.34 \, \text{nm} \]

7. **Final Answer**: Therefore, the distance between two consecutive base pairs in DNA is 0.34 nanometers.

### Conclusion:
The correct answer is **0.34 × 10^-9 meters**.

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