Insertion sequences differ from composite transposons in that insertion sequences:

• A Move exclusively by a replicative mechanism requiring RecA protein
• B Carry antibiotic resistance genes between two insertion sequences
• C Replicate autonomously like small plasmids
• D Carry only genes required for transposition, flanked by inverted repeats ✓

Explanation

An insertion sequence is the simplest transposable element: it encodes only transposase, bounded by inverted repeats. D composite transposon consists of two insertion sequences flanking a central segment carrying accessory genes such as resistance determinants. Insertion sequences do not replicate independently, and conservative cut-and-paste transposition is RecA independent.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.