Biology Biomolecules NUMS 2019
PMDC Verified Question 125 of 142
Which of the following are the most prominent part of cell membranes in living organisms?
A
Terpenoids
B
Waxes
C
Phospholipids
D
Acylglycerols
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option C: Phospholipids
Concept:

The physical boundary of every living cell on Earth relies on the spontaneous self-assembly of specific amphipathic molecules.

Solution:

  • Phospholipids are uniquely structured with a hydrophilic head and hydrophobic tails.


  • When placed in an aqueous environment, they spontaneously arrange themselves tail-to-tail to form the lipid bilayer, effectively hiding their hydrophobic tails from water.


  • This bilayer forms the primary, ubiquitous structural matrix (the most prominent part) of all plasma membranes across all domains of life.


Why other options are incorrect:

  • Acylglycerols (Triglycerides) & Waxes: Wholly non-polar molecules used primarily for energy storage and waterproofing, respectively; they cannot form a bilayer.


  • Terpenoids: While some derivatives (like cholesterol) exist in membranes, they act as minor fluid-modifiers, not the prominent structural matrix itself.

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 Biomolecules 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