What technique involves the transfer of DNA segments from one organism to another using plasmids?

• A. Gene cloning
• B. Polymerase chain reaction
• C. Gene therapy
• D. Transformation

Answer: (D)

The technique that involves the transfer of DNA segments from one organism to another using plasmids is transformation. In this process, plasmids—small, circular pieces of DNA—are introduced into a host organism, typically bacteria. When bacteria take up these plasmids, they can express the genes carried on them. Transformation is a natural process that some bacteria can perform, allowing them to acquire new genetic traits, which can be beneficial for adapting to new environments or acquiring antibiotic resistance.

Gene cloning involves creating copies of a particular gene or segment of DNA, but it doesn’t necessarily indicate the transfer of DNA into another organism. Instead, it usually refers to replicating the DNA within a host organism. Polymerase chain reaction (PCR) is a method used to amplify DNA, making millions of copies of a specific segment, but it does not involve transferring DNA between organisms. Gene therapy is a technique used to treat or prevent disease by inserting genes into a patient's cells, often to replace faulty genes, but it does not specifically focus on the use of plasmids as a general mechanism for transferring DNA between organisms.

Transformation effectively embodies the concept of transferring genetic material from one organism to another, particularly in research and biotechnology, making it the correct answer.