Which component of the cytoskeleton provides structure and support to the cell?

• A. Microtubules
• B. Keratin
• C. Mitochondria
• D. Lysosome

Answer: (B)

Keratin is a protein that makes up intermediate filaments, a key part of the cytoskeleton that gives cells mechanical strength. These filaments form a supportive network that resists pulling and bending forces, helping cells keep their shape and stay intact under stress. In tissues, keratin filaments link to desmosomes, strengthening connections between cells and supporting overall tissue integrity. Microfilaments (actin) and microtubules also play roles in shape and movement, but the structural backbone most linked to sustained mechanical support is provided by intermediate filaments like keratin. Mitochondria and lysosomes are organelles, not filaments, so they don’t provide this structural framework.