In a DNA strand the nucleotides are linked together by

Options

A. glycosidic bonds
B. phosphodiester bonds
C. peptide bonds
D. hydrogen bonds

Explanation

To answer the question "In a DNA strand, the nucleotides are linked together by," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding DNA Structure**:
- DNA (deoxyribonucleic acid) is a double-stranded molecule composed of nucleotides. Each nucleotide consists of a sugar (deoxyribose), a phosphate group, and a nitrogenous base.

2. **Identifying Nucleotide Linkage**:
- In a DNA strand, nucleotides are connected to each other to form a long chain. This connection is crucial for the stability and integrity of the DNA structure.

3. **Recognizing the Type of Bond**:
- The linkage between nucleotides occurs through a specific type of bond. This bond is formed between the phosphate group of one nucleotide and the 3' carbon of the sugar of the next nucleotide.

4. **Naming the Bond**:
- The bond that links the nucleotides together is known as a **phosphodiester bond**. This bond is formed through a dehydration reaction, where a water molecule is released.

5. **Conclusion**:
- Therefore, the correct answer to the question is that in a DNA strand, the nucleotides are linked together by **phosphodiester bonds**.

### Final Answer:
The nucleotides in a DNA strand are linked together by **phosphodiester bonds**.

---