Questions: Chromatin fibers condense and become visible chromosomes The centromeres of all of the chromosomes are lined up in the center of the cell Microtubules not attached to kinetochores lengthen, causing the cell to elongate

To answer the question, we need to match each description with the correct phase of mitosis.

1. "Chromatin fibers condense and become visible chromosomes" - This description corresponds to Prophase. During prophase, chromatin fibers condense into visible chromosomes, and the mitotic spindle begins to form.

2. "The centromeres of all of the chromosomes are lined up in the center of the cell" - This description corresponds to Metaphase. In metaphase, chromosomes are aligned at the metaphase plate, which is the center of the cell.

3. "Microtubules not attached to kinetochores lengthen, causing the cell to elongate" - This description corresponds to Anaphase. During anaphase, the sister chromatids are pulled apart, and the non-kinetochore microtubules lengthen, pushing the poles of the cell apart and causing the cell to elongate.

In summary:

• Chromatin fibers condense and become visible chromosomes: Prophase
• The centromeres of all of the chromosomes are lined up in the center of the cell: Metaphase
• Microtubules not attached to kinetochores lengthen, causing the cell to elongate: Anaphase