The small rounded knob like fragment in a chromosome lying beyond the secondary constriction is

Options

A. Centromere
B. Kinetochore
C. Satellite
D. Telomere

Answer

To solve the question regarding the small rounded knob-like fragment in a chromosome lying beyond the secondary constriction, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Chromosome Structure**:
- Begin by familiarizing yourself with the basic structure of a chromosome, which includes the centromere, chromatids, and various other components.

2. **Identifying Key Terms**:
- The question presents four options: centromere, kinetochore, satellite, and telomere. It is essential to understand what each term represents in the context of chromosome structure.

3. **Analyzing the Options**:
- **Centromere**: This is the region of the chromosome that links sister chromatids. It is located at the center of the chromosome and is not beyond the secondary constriction.
- **Kinetochore**: This is a protein structure that forms on the centromere during cell division. It is responsible for the movement of chromosomes but is also not located beyond the secondary constriction.
- **Telomere**: These are the end caps of chromosomes that protect them from deterioration. They are located at the ends of the chromatids, not beyond the secondary constriction.
- **Satellite**: This refers to small, rounded knob-like structures that can be found on chromosomes, specifically beyond the secondary constriction.

4. **Conclusion**:
- Based on the analysis, the correct answer is **satellite**, as it is the only option that describes the small rounded knob-like fragment located beyond the secondary constriction in a chromosome.

### Final Answer:
The small rounded knob-like fragment in a chromosome lying beyond the secondary constriction is **satellite**.