When a mature mRNA was hybridized to its gene, certain loops were observed. These loops represent

Options

A. introns in DNA
B. introns in rRNA
C. exons in tRNA
D. exons in DNA

Answer

To solve the question regarding the observation of loops when a mature mRNA hybridizes to its gene, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding mRNA and Gene Structure**:
- Mature mRNA is formed after the processing of pre-mRNA, which includes the removal of non-coding sequences called introns and the joining of coding sequences called exons.

2. **Hybridization Process**:
- When mature mRNA hybridizes with its corresponding DNA gene, it pairs with the exons of the gene. The introns, which are present in the DNA but not in the mature mRNA, will not have complementary sequences to hybridize with.

3. **Formation of Loops**:
- The regions of the DNA that correspond to the introns will not hybridize with any part of the mature mRNA. As a result, these non-hybridized regions will appear as loops during the hybridization process.

4. **Conclusion**:
- Therefore, the loops observed in the hybridization represent the introns in the DNA. These loops indicate the segments of the DNA that are not included in the mature mRNA, as they have been spliced out during mRNA processing.

### Final Answer:
The loops observed when a mature mRNA is hybridized to its gene represent **introns in DNA**.

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