Biology Cell NUMS 2022
PMDC Verified Question 78 of 143
A group of ribosomes attached to mRNA is known as polysome and the attachment is controlled by:
A
\(\text{K}^+\)
B
\(\text{Ca}^{+2}\)
C
\(\text{Mg}^{+2}\)
D
\(\text{Na}^+\)
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option C: \(\text{Mg}^{+2}\)
Concept: Ribosomal subunits are typically separate in the cytoplasm and only associate to form an active ribosome during protein synthesis.

Solution: The association of the large and small ribosomal subunits to form a functional ribosome (and subsequently attach to mRNA as a polysome) is strictly dependent on the concentration of magnesium ions, \(\text{Mg}^{+2}\).

Distractor Autopsy: Sodium, Calcium, and Potassium ions are essential for cellular functions like nerve impulses, but are not the primary agents for ribosomal subunit binding.

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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