One strand of the given segment of DNA codes for mRNA having the sequence AUC, GCG, UCA needed for the synthesis of proteins. Tne strand by which DNA molecule will be responsible for the above mRNA sequence is

Options

A.
B.
C.
D.

Answer

To determine the DNA strand responsible for the given mRNA sequence (AUC, GCG, UCA), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Base Pairing Rules**:
- In RNA, adenine (A) pairs with uracil (U), and guanine (G) pairs with cytosine (C).
- In DNA, adenine (A) pairs with thymine (T), and guanine (G) pairs with cytosine (C).

2. **Write Down the mRNA Sequence**:
- The given mRNA sequence is: AUC, GCG, UCA.

3. **Determine the Template DNA Strand**:
- For each mRNA nucleotide, we find the corresponding DNA nucleotide:
- A (in mRNA) pairs with T (in DNA).
- U (in mRNA) pairs with A (in DNA).
- C (in mRNA) pairs with G (in DNA).
- G (in mRNA) pairs with C (in DNA).

- Using this information, we can convert the mRNA sequence to the template DNA strand:
- AUC (mRNA) → TAG (DNA)
- GCG (mRNA) → CGC (DNA)
- UCA (mRNA) → AGT (DNA)

- Therefore, the template DNA strand is: TAG, CGC, AGT.

4. **Determine the Non-Template DNA Strand**:
- The non-template strand is the complementary strand to the template strand:
- TAG → ATC
- CGC → GCG
- AGT → TCA

- Thus, the non-template DNA strand is: ATC, GCG, TCA.

5. **Identify the Correct Option**:
- Now we need to check the options provided in the question to find the one that matches the template strand (TAG, CGC, AGT).

### Conclusion:
The DNA strand responsible for the mRNA sequence AUC, GCG, UCA is the template strand: **TAG, CGC, AGT**.