Length of the DNA with 23 base pairs įs:

Options

A. 78.4 Å
B. 78.2 Å
C. 78 Å
D. 74.8 Å

Explanation

To find the length of DNA with 23 base pairs, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Distance Between Base Pairs**:
- In double-stranded DNA, the distance between each base pair is known to be 3.4 angstroms (Å).

2. **Identify the Number of Base Pairs**:
- The question states that we have 23 base pairs.

3. **Calculate the Total Length of DNA**:
- To find the total length of DNA, we multiply the number of base pairs by the distance between each base pair.
- Formula:
\[ \text{Total Length} = \text{Number of Base Pairs} \times \text{Distance per Base Pair} \]
- Substituting the values:
\[ \text{Total Length} = 23 \text{ base pairs} \times 3.4 \text{ Å} \]

4. **Perform the Calculation**:
- Calculate:
\[ 23 \times 3.4 = 78.2 \text{ Å} \]

5. **Select the Correct Option**:
- From the given options (78.4 Å, 78.2 Å, 78 Å, 74.8 Å), the correct answer is 78.2 Å.

### Final Answer:
The length of DNA with 23 base pairs is **78.2 angstroms (Å)**.

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