Microtubules play a critical role in cell division, particularly during mitosis. Their main importance lies in the formation and function of the mitotic spindle, which is essential for the proper segregation of chromosomes. Here are the key points regarding the importance of microtubules in cell division:
-
Organizing Chromosomes: Microtubules help organize the replicated chromosomes during metaphase by attaching to kinetochores (protein structures on the chromosome) and aligning the chromosomes at the metaphase plate.
-
Separating Chromosomes: During anaphase, microtubules shorten, pulling the sister chromatids apart toward opposite poles of the cell. This ensures that each new daughter cell receives an identical set of chromosomes.
-
Forming the Mitotic Spindle: The mitotic spindle is largely composed of microtubules and is responsible for the movement of chromosomes. It is formed from the centrosomes (microtubule-organizing centers) and is crucial for the accurate division of genetic material.
-
Cytokinesis Support: While microtubules primarily focus on chromosome movement, they also assist in cytokinesis, the process of cytoplasmic division, by providing structural support and guiding the separation of the cell into two new daughter cells.
In summary, microtubules organize, pull apart, and facilitate the movement of chromosomes during cell division, ensuring that the process occurs correctly and efficiently. Hence, the best answer from your provided options is:
They organize and pull apart the chromosomes.