Biology Cell ETEA 2023 Retake
PMDC Verified Question 40 of 143
____ regulates the selective permeability of the plasma membrane, allowing movement of molecules according to the needs of the cells.
A
Membrane cholesterol
B
Membrane carbohydrates
C
Membrane glycolysis
D
Membrane proteins
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option D: Membrane proteins
Concept: While lipids provide the barrier, proteins act as the selective gates.

Solution: Membrane proteins (acting as channels, carriers, and pumps) dynamically regulate the selective permeability of the membrane. They selectively facilitate the movement of specific ions and polar molecules into or out of the cell based on cellular requirements.

Distractor Autopsy: Cholesterol regulates fluidity. Carbohydrates handle cell recognition. The lipid bilayer itself is a non-selective barrier to polar substances.

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.

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