Which is different in related species

Options

A. (a) Position of centromeres
B. (b) Position of NOR
C. (c) Satellite DNA
D. (d) All the above.

Answer

To solve the question "Which is different in related species?", we will analyze the provided options step by step.

### Step-by-Step Solution:

1. **Understanding Related Species**:
- Related species share a common ancestor and often have similar genetic makeups. However, certain genetic characteristics can vary among them.

2. **Evaluating Option A: Position of Centromere**:
- The centromere is the region of a chromosome where the two sister chromatids are joined. The position of centromeres is generally conserved among related species, meaning it does not vary significantly.
- **Conclusion**: This option is incorrect.

3. **Evaluating Option B: Position of NOR (Nucleolus Organizer Region)**:
- The Nucleolus Organizer Region is a chromosomal region crucial for the formation of the nucleolus. Similar to centromeres, the position of NORs is also relatively consistent across related species.
- **Conclusion**: This option is also incorrect.

4. **Evaluating Option C: Satellite DNA**:
- Satellite DNA consists of repetitive sequences that can vary significantly between individuals, even among related species. These variations are due to the unique patterns of short tandem repeats (STRs) that can differ from one individual to another.
- **Conclusion**: This option is correct as satellite DNA is different in related species.

5. **Final Answer**:
- The correct answer is **C: Satellite DNA**.