Which organelle is responsible for forming the fibers required for cell division?

• A. Ribosomes
• B. Centrioles
• C. Lysosomes
• D. Plasma

Answer: (B)

During cell division, the fibers that pull chromosomes apart form the mitotic spindle, which is made of microtubules. The organizer of these fibers in animal cells is the centrosome, containing a pair of centrioles. These cylindrical structures help organize and stabilize the growing microtubules that extend to form the spindle poles, guiding chromosomes to opposite sides of the cell. Ribosomes synthesize proteins, lysosomes digested waste, and the plasma membrane defines the cell boundary—none of these create the spindle fibers. So, centrioles are the organelles most involved in forming the fibers needed for cell division.