Which of the following features (P-S) can be observed in the eukaryotic chromosome?
P-Telomeres, Q-Centromere, R- Euchromatin, S-Origin of DNA replication

Options

A. P and Q
B. P, Q and S
C. P and S
D. P, Q, R, and S

Answer

To solve the question regarding the features that can be observed in a eukaryotic chromosome, we will analyze each feature listed (P-S) one by one.

### Step-by-Step Solution:

1. **Understanding Telomeres (P)**:
- Telomeres are the protective caps located at the ends of linear chromosomes. They consist of repetitive nucleotide sequences and play a crucial role in maintaining chromosome stability and preventing degradation.
- **Conclusion**: Telomeres are present in eukaryotic chromosomes.

2. **Understanding Centromeres (Q)**:
- The centromere is the constricted region of a chromosome that links sister chromatids together. It is essential for proper segregation of chromosomes during cell division.
- **Conclusion**: Centromeres are present in eukaryotic chromosomes.

3. **Understanding Euchromatin (R)**:
- Euchromatin is a form of chromatin that is less condensed and is transcriptionally active. It is where most of the gene expression occurs, allowing for the transcription of DNA into RNA.
- **Conclusion**: Euchromatin is present in eukaryotic chromosomes.

4. **Understanding the Origin of DNA Replication (S)**:
- The origin of DNA replication is the specific sequence where DNA replication begins. This is crucial for the duplication of the genetic material before cell division.
- **Conclusion**: The origin of DNA replication is present in eukaryotic chromosomes.

### Final Conclusion:
Since all four features (P, Q, R, and S) are observed in eukaryotic chromosomes, the correct answer is:
**P, Q, R, and S**.