Number of nitrogen bases in a single strand of B-DNA with 100 turns is

Options

A. 500
B. 1000
C. 2000
D. 250

Answer

To find the number of nitrogen bases in a single strand of B-DNA with 100 turns, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of B-DNA**:
- B-DNA is a double helix structure where two strands are coiled around each other. Each complete turn of the helix contains a specific number of nitrogenous bases.

2. **Identify the Number of Bases per Turn**:
- In B-DNA, one complete turn of the helix contains approximately 10 base pairs. Since we are considering a single strand, we will still count the bases in terms of pairs.

3. **Calculate the Total Number of Bases for 100 Turns**:
- If there are 10 bases in one turn, then for 100 turns, we multiply the number of bases per turn by the number of turns:
\[ \text{Total Bases} = \text{Number of Bases per Turn} \times \text{Number of Turns} \]
\[ \text{Total Bases} = 10 \text{ bases/turn} \times 100 \text{ turns} = 1000 \text{ bases} \]

4. **Conclusion**:
- Therefore, the number of nitrogen bases in a single strand of B-DNA with 100 turns is **1000**.

### Final Answer:
The number of nitrogen bases in a single strand of B-DNA with 100 turns is **1000**.

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