The minimum and maximum number of hydrogen bonds
found in a coil of ds-DNA respectively are

Options

A. 10 and 10
B. 20 and 20
C. 30 and 20
D. 20 and 30

Answer

To solve the question regarding the minimum and maximum number of hydrogen bonds found in a coil of double-stranded DNA (ds-DNA), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Structure of DNA**:
- DNA is composed of two strands that coil around each other, forming a double helix. Each strand is made up of nucleotides, which include a sugar, a phosphate group, and a nitrogenous base.

2. **Identify the Nitrogenous Bases**:
- The nitrogenous bases in DNA are adenine (A), thymine (T), guanine (G), and cytosine (C).
- Adenine pairs with thymine (A-T) through 2 hydrogen bonds.
- Guanine pairs with cytosine (G-C) through 3 hydrogen bonds.

3. **Determine the Number of Base Pairs**:
- For this question, we will assume there are 10 base pairs in the DNA coil.

4. **Calculate the Minimum Number of Hydrogen Bonds**:
- The minimum number of hydrogen bonds occurs when all base pairs are A-T pairs.
- Each A-T pair has 2 hydrogen bonds. Therefore, for 10 base pairs:
\[ \text{Minimum hydrogen bonds} = 10 \text{ base pairs} \times 2 \text{ bonds/base pair} = 20 \text{ hydrogen bonds} \]

5. **Calculate the Maximum Number of Hydrogen Bonds**:
- The maximum number of hydrogen bonds occurs when all base pairs are G-C pairs.
- Each G-C pair has 3 hydrogen bonds. Therefore, for 10 base pairs:
\[ \text{Maximum hydrogen bonds} = 10 \text{ base pairs} \times 3 \text{ bonds/base pair} = 30 \text{ hydrogen bonds} \]

6. **Conclusion**:
- The minimum number of hydrogen bonds in a coil of ds-DNA is 20, and the maximum number is 30.
- Therefore, the answer is: Minimum = 20, Maximum = 30.

### Final Answer:
The minimum and maximum number of hydrogen bonds found in a coil of ds-DNA are 20 and 30, respectively.

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