Shuttle vectors are not exemplified by

Options

A. Yep
B. Ti plasmid
C. BAC
D. Both (2) & (3)

Answer

**Step-by-Step Solution:**

1. **Understanding Shuttle Vectors**:
- Shuttle vectors are specialized vectors designed to replicate in two different host organisms, typically one eukaryotic and one prokaryotic. This allows for the transfer of genetic material between different types of cells.

2. **Identifying Examples of Shuttle Vectors**:
- Common examples of shuttle vectors include:
- **YEP (Yeast Episomal Plasmid)**: This vector can replicate in both *E. coli* (a prokaryote) and yeast (a eukaryote), making it a shuttle vector.
- **Ti-Plasmid (Tumor-inducing plasmid)**: This binary vector can replicate in *Agrobacterium* (a prokaryote) and *E. coli* (another prokaryote), thus it is also considered a shuttle vector.

3. **Evaluating BAC (Bacterial Artificial Chromosome)**:
- BACs are designed to replicate only in bacterial cells, specifically in *E. coli*. Since they do not replicate in a eukaryotic host, they do not qualify as shuttle vectors.

4. **Conclusion**:
- Based on the definitions and examples provided, the correct answer to the question "Shuttle vectors are not exemplified by" is **BAC (Bacterial Artificial Chromosome)**, as it does not propagate in two different host species.

**Final Answer**: Shuttle vectors are not exemplified by BAC (Bacterial Artificial Chromosome).

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