Question

Sol.(a) [Key Concept: Induced Mutations — High-energy Radiation] Mutations can be induced in bacteria by exposure to high energy radiations (UV radiation, X-rays, gamma rays) or chemical mutagens. High-energy radiation causes DNA damage — it can break phosphodiester bonds, cause pyrimidine dimers (UV), or ionise DNA bases, leading to base substitutions, insertions, or deletions (mutations).