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 answer the question about the loops observed when a mature mRNA is hybridized to its gene, we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Understanding mRNA and Genes**:
- Mature mRNA is the final product of gene expression after transcription and RNA processing. It contains only the coding sequences (exons) that are expressed in proteins.

2. **Identifying Components of a Gene**:
- A gene consists of both exons (coding sequences) and introns (non-coding sequences). During the process of RNA splicing, introns are removed from the pre-mRNA, leaving only exons.

3. **Hybridization Process**:
- When mature mRNA hybridizes with its corresponding gene, the complementary sequences will bind together. However, since introns are not present in the mature mRNA, they will not hybridize.

4. **Observation of Loops**:
- The loops observed during hybridization represent the regions of the gene that correspond to introns. These introns do not have a complementary sequence in the mature mRNA, leading to the formation of loops.

5. **Conclusion**:
- Therefore, the loops observed in the hybridization of mature mRNA to its gene represent the introns in DNA.

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

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