Which organelle is essential for pulling apart chromosomes during animal cell division?

• A. Endoplasmic Reticulum
• B. Centrioles
• C. Lysosome
• D. Chloroplast

Answer: (B)

The key idea is how chromosomes are pulled apart during animal cell division and which organelle helps organize the spindle that does the pulling. In animal cells, the spindle apparatus is built by centrosomes at opposite poles, and centrioles are part of those centrosomes. They help organize the microtubules that reach out to each chromosome at the kinetochores. As cell division progresses, these microtubules shorten and pull the sister chromatids toward opposite poles, separating them into two new cells. The other organelles listed don’t drive this process: the endoplasmic reticulum is for protein and lipid synthesis, the lysosome digests waste and invaders, and chloroplasts carry out photosynthesis in plants.