Assertion : All expression vectors are cloning vectors and vise versa.
Reason : Expression vectors have at least the regulatory sequences i.e., promotes, operators, ribosomal binding sites, etc having optimum function in the chosen control but not origin of replication.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understand the Assertion
The assertion states: "All expression vectors are cloning vectors and vice versa."
- **Cloning vectors** are designed to replicate and maintain recombinant DNA in host cells. They are primarily used for cloning DNA fragments.
- **Expression vectors**, on the other hand, are designed to express a gene of interest in a host organism. They contain necessary regulatory elements like promoters and ribosomal binding sites to facilitate gene expression.

**Conclusion for Step 1**: The assertion is incorrect because not all expression vectors can function as cloning vectors, and vice versa.

### Step 2: Understand the Reason
The reason states: "Expression vectors have at least the regulatory sequences i.e., promoters, operators, ribosomal binding sites, etc., having optimum function in the chosen control but not origin of replication."
- While it is true that expression vectors contain regulatory sequences, the statement that they do not have an origin of replication (Ori) is incorrect. An origin of replication is essential for any vector, including expression vectors, to ensure that the DNA is replicated within the host cell.

**Conclusion for Step 2**: The reason is also incorrect because expression vectors must include an origin of replication to function properly.

### Step 3: Evaluate the Options
Based on our conclusions:
- Both the assertion and the reason are false.
- Therefore, the correct option is D: "Both assertion and reason are false."

### Final Answer
The correct answer is **Option D: Both assertion and reason are false.**

---