During mitosis and cell division, spindle fibers are associated with what organelle?

Spindle fibers are structures formed during cell division that play a crucial role in separating chromosomes to ensure each new daughter cell receives the correct number of chromosomes. These spindle fibers are associated with the centrosomes, which are organelles that serve as the main microtubule organizing centers in animal cells.

During mitosis, the centrosomes duplicate and move to opposite poles of the cell, where they help to organize the spindle fibers. The microtubules that make up the spindle fibers extend from the centrosomes and attach to the kinetochores of the chromosomes, facilitating their alignment and eventual separation. This association between spindle fibers and centrosomes is essential for the proper distribution of genetic material during cell division.

In contrast, lysosomes are involved in breaking down waste materials and cellular debris, mitochondria are known as the powerhouses of the cell because they produce energy, and vacuoles serve various roles such as storage and maintaining turgor pressure in plant cells. These organelles do not play a direct role in the formation or function of spindle fibers during mitosis.