The cytoskeleton of eukaryotic cells primarily consists of microtubules and microfilaments, making option 1 [(B) and (D) only] the correct answer.

Option Analysis

• (A) Peptidoglycans: Incorrect; these are bacterial cell wall components, not part of eukaryotic cytoskeletons.​

• (B) Microtubules: Correct; hollow tubes of tubulin proteins that maintain cell shape, aid mitosis, and enable intracellular transport.

• (C) Chitin: Incorrect; a polysaccharide in fungal cell walls and arthropod exoskeletons, absent from cytoskeletons.​

• (D) Microfilaments: Correct; actin filaments involved in cell motility, cytokinesis, and structural support.

• (E) Cellulose: Incorrect; a plant cell wall polymer, not found in eukaryotic cytoskeletons.​

The cytoskeleton of eukaryotic cells forms a dynamic protein network essential for structure, motility, and division. Unlike prokaryotes, eukaryotic cytoskeletons rely on three main protein filaments: microtubules, microfilaments (actin), and intermediate filaments. This setup supports intracellular transport and adapts rapidly to cellular needs.

Core Components

• Microtubules provide rigidity and tracks for vesicle movement; they are tubulin-based and key in mitosis.​

• Microfilaments drive contraction and shape changes via actin polymerization.​

• Intermediate filaments offer tensile strength, though not listed in the options.​

Why Other Options Fail

Peptidoglycans define bacterial walls, chitin strengthens fungi/insects, and cellulose rigidifies plants—none integrate into eukaryotic cytoplasmic scaffolds.​

For GATE Life Sciences aspirants in India, mastering the cytoskeleton of eukaryotic cells distinguishes it from cell walls, aiding PYQ success like this one.​