Which of the following sequence is palindromic ?

Options

A. GAATTC
CTTAAG
B. ATGCAG
TACGTC
C. CTTAGC
GAATCG
D. TGCATC
ACGTAG

Answer

To determine which of the provided sequences is palindromic, we need to follow these steps:

### Step 1: Understand the Definition of a Palindromic Sequence
A palindromic sequence is one that reads the same in both directions. For DNA sequences, this means that if you read the sequence from the 5' end to the 3' end, it should be identical to reading it from the 3' end to the 5' end.

### Step 2: Analyze Each Sequence
We will analyze the sequences provided in the question to check if they are palindromic.

1. **Sequence 1: g a a g a a t t c**
- Reading from 5' to 3': g a a g a a t t c
- Reading from 3' to 5': c t t a a g g a
- Not the same, so this is not palindromic.

2. **Sequence 2: a t c t**
- Reading from 5' to 3': a t c t
- Reading from 3' to 5': t c t a
- Not the same, so this is not palindromic.

3. **Sequence 3: c t t a**
- Reading from 5' to 3': c t t a
- Reading from 3' to 5': t a t c
- Not the same, so this is not palindromic.

4. **Sequence 4: g a a g**
- Reading from 5' to 3': g a a g
- Reading from 3' to 5': g a a g
- The same in both directions, so this is a palindromic sequence.

### Step 3: Conclusion
The palindromic sequence among the options provided is **g a a g**.

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