In the polynucleotide chain of DNA, a nitrogenous base is linked to the -OH of:

Options

A. 2'C pentose sugar
B. 3'C pentose sugar
C. 5'C penotse sugar
D. 1'C pentose sugar

Answer

To solve the question "In the polynucleotide chain of DNA, a nitrogenous base is linked to the -OH of:", we will break down the components of DNA and identify where the nitrogenous base is attached.

### Step-by-Step Solution:

1. **Understand the Structure of DNA**:
- DNA (deoxyribonucleic acid) consists of three main components: a nitrogenous base, a pentose sugar (deoxyribose), and a phosphate group.

2. **Identify the Components**:
- The nitrogenous bases can be classified into two categories: purines (adenine and guanine) and pyrimidines (cytosine and thymine).
- The sugar in DNA is deoxyribose, which is a five-carbon sugar.

3. **Locate the -OH Group**:
- In the structure of deoxyribose, the carbons are numbered from 1' to 5'. The -OH group is specifically attached to the 3' carbon and the 5' carbon has a phosphate group attached.

4. **Determine the Linkage**:
- The nitrogenous base is linked to the 1' carbon of the deoxyribose sugar. This is where the base attaches to the sugar, forming a nucleoside.

5. **Conclusion**:
- Therefore, in the polynucleotide chain of DNA, the nitrogenous base is linked to the -OH group of the **first carbon** of the pentose sugar.

### Final Answer:
The nitrogenous base is linked to the -OH of the **first carbon of pentose sugar**.