Charon 34 and Charon 35 are examples of which type of cloning vectors derived from bacteriophage systems?

Introduction / Context:
Historically important lambda vectors, such as the Charon series, enabled efficient cloning and library construction. Recognizing vector families by name is useful when reading older literature or troubleshooting legacy protocols.

Given Data / Assumptions:

• Charon vectors are associated with bacteriophage lambda.
• They exploit lambda packaging and infection to deliver recombinant DNA into E. coli.
• They are not cosmids, plasmids, or modern BACs.

Concept / Approach:
Lambda vectors come in insertion and replacement forms, each with specific insert capacities and map features. The Charon series, like other lambda vectors, leverages headful packaging constraints and cos sites for efficient transduction and plaque formation to identify recombinants.

Step-by-Step Solution:

Verification / Alternative check:
Reference maps list Charon vectors with lambda arms, selectable markers, and sites engineered for replacement cloning strategies.

Why Other Options Are Wrong:

• A: Plasmids replicate by ori-based replication; Charons rely on phage lambda life cycle features.
• B: Cosmids are plasmids with cos sites; Charon vectors are bona fide lambda phage derivatives.
• D: Phagemids are plasmids with filamentous phage origins, not lambda.
• E: BACs are large plasmid systems based on F-factor replicons.

Common Pitfalls:
Confusing cosmids (cos-containing plasmids) with clear lambda phage vectors due to the shared “cos” term.

Final Answer:
Lambda (phage λ) vectors