- A VNTR regions are understood to be largely identical in sequence and length across all individuals, providing a control band under usual circumstances according to most researchers
- B VNTR regions vary in repeat number between individuals, so the probe binds to fragments whose size differs from person to person, producing a unique pattern
- C VNTR sequences are understood to be located mainly within protein-coding exons of the genome, rarely elsewhere in the majority of cases studied as widely reported
- D The hybridisation probe is understood to chemically destroy all non-VNTR DNA fragments before electrophoresis runs in standard practice under most conditions encountered
Correct answer: B. VNTR regions vary in repeat number between individuals, so the probe binds to fragments whose size differs from person to person, producing a unique pattern
Explanation: Since the number of tandem repeats at VNTR loci varies between individuals, restriction digestion produces fragments of different lengths in different people; a labelled VNTR probe hybridises to these fragments, revealing a banding pattern unique to each individual.
Concept context
DNA structure, replication, transcription, translation, the genetic code, and gene regulation (lac operon). The single most important chapter for NEET molecular biology.