Repetitive sequence are stretches of DNA with repeated bases many times of in a genome but.
(a) These sequence are of no transcriptional function.
(b) These are associated with euchromatin region .
(c) These helps to identify a person on the basis of its DNA specificity.

Options

A. All are correct
B. Only (b) is incorrect
C. Both (a) & (b) are correct
D. Both (b) & (c) are incorrect

Answer

To solve the question regarding repetitive sequences in DNA, we will analyze each statement provided and determine its validity.

### Step-by-Step Solution:

1. **Understanding Repetitive Sequences**:
- Repetitive sequences are stretches of DNA where certain base sequences are repeated multiple times. They are found throughout the genome and can vary in length and composition.

2. **Analyzing Statement (a)**:
- **Statement**: "These sequences are of no transcriptional function."
- **Analysis**: This statement is correct. Repetitive sequences typically do not code for proteins and are not involved in the transcription process. They do not contribute to the formation of RNA or proteins.

3. **Analyzing Statement (b)**:
- **Statement**: "These are associated with euchromatin region."
- **Analysis**: This statement is also correct. Euchromatin is a less condensed form of chromatin that is actively involved in transcription. Repetitive sequences can be found in euchromatin, which is more accessible for transcriptional machinery.

4. **Analyzing Statement (c)**:
- **Statement**: "These help to identify a person on the basis of its DNA specificity."
- **Analysis**: This statement is correct as well. Repetitive sequences, particularly those that show variation among individuals (such as microsatellites or short tandem repeats), are crucial for DNA fingerprinting and forensic analysis. They help in identifying individuals based on their unique DNA profiles.

5. **Conclusion**:
- All three statements (a), (b), and (c) are correct. Therefore, the answer is that all the statements about repetitive sequences are valid.

### Final Answer:
All statements about repetitive sequences are correct:
(a) These sequences are of no transcriptional function.
(b) These are associated with euchromatin region.
(c) These help to identify a person on the basis of its DNA specificity.

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