Question

Comment upon the following:
Plasmid Vector

Hint:

Plasmids are the most commonly used vectors in recombinant DNA technology due to their easy replication and modification.

Answer 1

A plasmid vector is a small, circular, double-stranded DNA molecule found in bacteria, separate from the chromosomal DNA. It can replicate independently and is widely used in genetic engineering as a vehicle to transfer foreign DNA into host cells. 

Key Features of Plasmid Vectors: \[\begin{array}{rl} 1. & \text{Origin of Replication (Ori): Ensures independent replication inside host cells.} \\ 2. & \text{Selectable Marker: Genes such as antibiotic resistance markers (e.g., ampicillin resistance) help in identifying transformed cells.} \\ 3. & \text{Cloning Sites: Multiple Cloning Sites (MCS) allow easy insertion of foreign DNA.} \\ 4. & \text{Size: Small size makes them easy to manipulate in the laboratory.} \\ \end{array}\]

Example: pBR322, pUC19.