Read the following statements and choose the correct option.
A. Nitrogenous base is linked to the pentose sugar through a N-glycosidic linkage.
B. Phosphate group is linked to 5'-OH of a nucleoside through phosphoester linkage.
C. Two nucleosides are linked through 3'-5' N-glycosidic linkage.
Negatively charged DNA is wrapped around positively charged histone octamer to form nucleosome.
E. The chromatin that is more densely packed and stains dark is called euchromatin.

Options

A. A, B and C alone are wrong
B. D along is wrong
C. C and E alone are wrong
D. A alone is wrong

Answer

To solve the question, we need to evaluate each statement provided and determine whether it is correct or incorrect. Let's analyze each statement step by step.

### Step-by-Step Solution:

1. **Statement A**: "Nitrogenous base is linked to the pentose sugar through a N-glycosidic linkage."
- **Analysis**: This statement is correct. In nucleotides, the nitrogenous base is indeed linked to the pentose sugar (ribose or deoxyribose) via an N-glycosidic bond.

2. **Statement B**: "Phosphate group is linked to 5'-OH of a nucleoside through phosphoester linkage."
- **Analysis**: This statement is also correct. The phosphate group attaches to the 5' hydroxyl group of the sugar in a nucleoside through a phosphoester bond, forming a nucleotide.

3. **Statement C**: "Two nucleosides are linked through 3'-5' N-glycosidic linkage."
- **Analysis**: This statement is incorrect. Nucleosides are linked by phosphodiester bonds, not N-glycosidic linkages. The correct linkage between nucleotides is through a 3'-5' phosphodiester bond.

4. **Statement D**: "Negatively charged DNA is wrapped around positively charged histone octamer to form nucleosome."
- **Analysis**: This statement is correct. DNA is negatively charged due to its phosphate backbone, and it wraps around positively charged histone proteins to form nucleosomes.

5. **Statement E**: "The chromatin that is more densely packed and stains dark is called euchromatin."
- **Analysis**: This statement is incorrect. The densely packed chromatin that stains dark is called heterochromatin, while euchromatin is less densely packed and stains lightly.

### Summary of Statements:
- **Correct Statements**: A, B, D
- **Incorrect Statements**: C, E

### Conclusion:
The correct option is that statements C and E are the only incorrect ones.

### Final Answer:
The correct option is C: "C and E alone are wrong."