If the sequence of nitrogen bases of the coding strand of DNA in a transcription unit is `5'-A T G A A T G -3'`, the sequence of bases in its RNA transcript would be

Options

A. 5'-A U G A A U G-3'
B. 5'- U A C U U A C-3'
C. 5'-C A U U C A U -3'
D. 5'- G U A A G UA -3'

Answer

To determine the RNA transcript from the given DNA coding strand sequence, we will follow these steps:

### Step 1: Identify the DNA coding strand
The given DNA coding strand sequence is:
```
5'-A T G A A T G-3'
```

### Step 2: Understand the transcription process
During transcription, the RNA polymerase reads the DNA template strand and synthesizes a complementary RNA strand. The RNA strand is synthesized in the 5' to 3' direction, and the base pairing rules differ slightly from DNA:
- Adenine (A) pairs with Uracil (U) in RNA (instead of Thymine in DNA).
- Thymine (T) in DNA pairs with Adenine (A) in RNA.
- Cytosine (C) pairs with Guanine (G), and vice versa.

### Step 3: Determine the complementary RNA sequence
Since the coding strand is given, we can directly convert it to the RNA transcript by replacing the bases according to the pairing rules mentioned above.

The coding strand sequence is:
```
5'-A T G A A T G-3'
```
Now we will convert this sequence to RNA:
- A (Adenine) → U (Uracil)
- T (Thymine) → A (Adenine)
- G (Guanine) → C (Cytosine)
- A (Adenine) → U (Uracil)
- A (Adenine) → U (Uracil)
- T (Thymine) → A (Adenine)
- G (Guanine) → C (Cytosine)

Thus, the RNA transcript will be:
```
5'-U A C U U A C-3'
```

### Step 4: Write the final answer
The sequence of bases in the RNA transcript is:
```
5'-U A C U U A C-3'
```

### Final Answer
The RNA transcript sequence is **5'-UAC UUA C-3'**.

---