What is the main distinction between anaphase and metaphase in cell division?

• A. Metaphase involves chromosomal separation.
• B. Metaphase features chromosomes lining up at the equatorial plane.
• C. Anaphase occurs before cytokinesis.
• D. Anaphase is when sister chromatids align at the equator.

Answer: (B)

The main distinction between anaphase and metaphase in cell division is that metaphase is characterized by chromosomes aligning at the equatorial plane, also known as the metaphase plate. During this stage, the chromosomes are maximally condensed and are attached to the spindle apparatus via their kinetochores. This alignment is crucial for ensuring that, during the subsequent stage of anaphase, sister chromatids can be pulled apart evenly to opposite poles of the cell.

In contrast, anaphase is when the actual separation of sister chromatids occurs. The proteins holding the sister chromatids together are cleaved, allowing them to move toward opposite poles of the cell due to the shortening of microtubules attached to them. Understanding this distinction is essential for grasping the entire process of mitosis, as proper alignment during metaphase ensures that each daughter cell receives an identical set of chromosomes.