The reverse order of nucleotide sequence found in the opposite DNA strands recognized by RE's are called

Options

A. Plasmids
B. Cosmids
C. Vectors
D. Palindromes

Answer

### Step-by-Step Solution:

1. **Understanding Restriction Enzymes (REs)**:
- Restriction enzymes, also known as restriction endonucleases, are proteins that cut DNA at specific sequences. They recognize specific nucleotide sequences in the DNA.

2. **Identifying the Nucleotide Sequence**:
- The nucleotide sequences recognized by restriction enzymes are often specific and can be found in both strands of the DNA.

3. **Defining Palindromic Sequences**:
- A palindromic sequence in DNA is a sequence that reads the same in the 5' to 3' direction on one strand and in the 3' to 5' direction on the complementary strand. This means that if you read the sequence from one end to the other, it will be identical to the sequence read in reverse on the opposite strand.

4. **Example of a Palindromic Sequence**:
- An example is the sequence 5' - GAATTC - 3' on one strand, which has a complementary strand of 3' - CTTAAG - 5'. If you read the first strand from left to right, it reads GAATTC, and if you read the complementary strand from right to left, it also reads GAATTC.

5. **Conclusion**:
- The reverse order of nucleotide sequences found in opposite DNA strands recognized by restriction enzymes is referred to as **palindromic sequences** or **palindromes**.

### Final Answer:
The reverse order of nucleotide sequence found in the opposite DNA strands recognized by restriction enzymes (REs) are called **palindromes**.

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