Bacterial artificial chromosomes (BACs), cosmids, phages, plasmids and yeast artifical chromosomes (YACs) are all commonly used cloning vectors that differ in their cloning capacities, with a range from approximately 100 bp to 1000 kb. Which of the following is the correct order for these vectors in terms of increasing cloning capacity ?

Options

A. BAC,cosmid,phage,plasmid,YAC
B. YAC,BAC,cosmid,phage,plasmid
C. Plasmid,phage,cosmid,BAC,YAC
D. Plasmid,cosmid,phage,BAC,YAC

Explanation

To determine the correct order of cloning vectors in terms of increasing cloning capacity, we need to know the approximate cloning capacities of each vector mentioned in the question. Here’s a step-by-step breakdown:

1. **Identify the Cloning Capacities**:
- **Plasmids**: Typically can clone DNA fragments up to about 15 kilobases (KB).
- **Phages**: Can accommodate DNA fragments up to about 23 KB.
- **Cosmids**: Have a cloning capacity of approximately 45 KB.
- **Bacterial Artificial Chromosomes (BACs)**: Can clone DNA fragments from 300 to 350 KB.
- **Yeast Artificial Chromosomes (YACs)**: Have the largest capacity, able to clone DNA fragments up to 1 megabase (MB), which is equivalent to 1000 KB.

2. **Arrange the Vectors by Cloning Capacity**:
- Start with the vector that has the smallest capacity and move to the one with the largest.
- The order based on the capacities identified is:
- Plasmids (up to 15 KB)
- Phages (up to 23 KB)
- Cosmids (up to 45 KB)
- BACs (up to 350 KB)
- YACs (up to 1000 KB)

3. **Final Order**:
- Thus, the correct order for these vectors in terms of increasing cloning capacity is:
- Plasmids < Phages < Cosmids < BACs < YACs

4. **Select the Correct Option**:
- Based on the order identified, the correct answer corresponds to option 3.