The coding strand of a transcriptional unit starts with sequence AGTCTAAG CTGAGACT.Which of the following sequences represents the mRNA transcribed from this transcriptional unit?

Options

A. AGUCUAAGCUGAGACU
B. UCAGAUUCGACUCUGA
C. AGUCUAACGACUGACU
D. AGTCTAAGCTGAGACT

Answer

To determine the mRNA sequence transcribed from the given coding strand of DNA, we need to follow these steps:

### Step 1: Identify the Coding Strand
The coding strand provided is:
**AGTCTAAGCTGAGACT**

### Step 2: Understand Transcription
During transcription, the coding strand of DNA serves as a template for the synthesis of mRNA. The mRNA sequence is complementary to the template strand and matches the coding strand, except that thymine (T) in DNA is replaced by uracil (U) in RNA.

### Step 3: Transcribe the Sequence
We will transcribe the coding strand into mRNA by replacing T with U:
- A → A
- G → G
- T → U
- C → C
- A → A
- T → U
- G → G
- A → A
- C → C
- T → U

Now, let's write out the transcribed mRNA sequence:
1. A → A
2. G → G
3. T → U
4. C → C
5. T → U
6. A → A
7. A → A
8. G → G
9. C → C
10. T → U
11. G → G
12. A → A
13. G → G
14. A → A
15. C → C
16. T → U

Thus, the mRNA sequence becomes:
**AGUCUAAGCUGAGACU**

### Step 4: Match with Options
Now we need to compare this mRNA sequence with the provided options to find the correct one.

### Final Answer
The mRNA transcribed from the coding strand **AGTCTAAGCTGAGACT** is:
**AGUCUAAGCUGAGACU**