Advanced Placement (AP) Biology Practice Exam

What role does the mitotic spindle play during cell division?

1. It synthesizes DNA

2. It helps in the movement of chromosomes

3. It condenses chromatin

4. It produces cellular energy

The correct answer is: It helps in the movement of chromosomes

The mitotic spindle plays a crucial role during cell division by facilitating the movement of chromosomes during mitosis and meiosis. It is composed of microtubules that extend from the centrosomes at opposite poles of the dividing cell. As the cell prepares to split, the spindle fibers attach to the kinetochores located at the centromeres of the chromosomes. This attachment allows the spindle fibers to generate forces that align the chromosomes along the metaphase plate and subsequently pull the sister chromatids apart toward opposite poles of the cell during anaphase. This mechanism ensures that each daughter cell receives an identical set of chromosomes, which is essential for maintaining genetic stability during cell division. Thus, the mitotic spindle is fundamental to accurate chromosome segregation and the overall success of the division process.