Which of the following are components of the cytoskeleton?

• A. Nucleic acids and ribosomes
• B. Enzymes and hormones
• C. Proteins, centrioles and centrosome matrix, microfilaments, microtubules, intermediate filaments
• D. Chloroplasts and mitochondria

Answer: (C)

The cytoskeleton is the cell’s internal framework, built from protein filaments that give shape, support, and organization, and that also drive movement and transport inside the cell. It includes three main filament systems: microfilaments (actin filaments), intermediate filaments, and microtubules. These filaments are dynamic, constantly assembling and disassembling to adapt to the cell’s needs. Structures such as centrioles and the centrosome matrix act as organizing centers that help assemble and organize the microtubules, which is especially important during cell division. Together, these protein filaments and organizing components make up the cytoskeleton. The other options describe molecules or organelles not forming the cytoskeletal network.