Biology Biotechnology SZABMU 2025
PMDC Verified Question 63 of 65
In gel electrophoresis, how do molecules migrate through the gel?
A
By diffusion
B
Under the influence of an electric field
C
Active transport
D
Under the influence of agar
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: Under the influence of an electric field
Concept:

Electrophoretic mobility of charged biological macromolecules.

Solution:

Gel electrophoresis separates biomolecules (DNA, RNA, proteins) based on size and charge as an applied external electric field forces negatively charged molecules (such as polyanionic DNA) to migrate toward the positive anode.

Why other options are incorrect:

  • By diffusion: Passive random molecular movement down concentration gradients does not achieve directional separation.


  • Active transport: ATP-dependent cellular transport mechanisms are absent in inanimate agarose/polyacrylamide gel matrices.


  • Under the influence of agar: The porous gel matrix acts as a molecular sieve; it does not supply the driving force for migration.

Quality & Fidelity Assurance: Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.

Previous Question All Biotechnology MCQs Next Question

Want to solve full-length papers under timed exam conditions?

Practice with zero-scroll lockdown sprints, dynamic latency zone timers, live peer selection telemetry, and the automated Amber mistake recovery loop.

Enter Arena Sprint iOS App Android App