Frederick Griffith is known for discovering transformation in bacteria. Which term describes that phenomenon?

• A. Transduction
• B. Transformation in bacteria
• C. Mutation
• D. Conjugation

Answer: (B)

Transformation in bacteria is the uptake of extracellular DNA by a competent cell, resulting in a heritable change in traits. Griffith showed that nonvirulent bacteria could become virulent after exposure to DNA released from dead virulent bacteria, demonstrating that genetic material can move from one organism to another and change its phenotype. This uptake-and-change process is what we call transformation in bacteria.

Transduction involves bacteriophages carrying DNA from one bacterium to another, and conjugation requires direct cell-to-cell contact to transfer DNA, often via a pilus. Mutation, on the other hand, is a change in the DNA sequence within a cell, not a transfer of DNA between cells. So the phenomenon Griffith described is transformation in bacteria.