Question

what is the defining event in metaphase? nuclear membrane forms around the two sets of chromatids at the far ends of the cell. dna condenses to chromosomes. the nuclear membrane breaks down. sister chromatids break apart and move to the opposite ends of the cell. chromosomes line up in the middle of the cell.

Explanation:

To determine the defining event of metaphase, we analyze each option:

• The first option describes telophase (nuclear membrane formation at cell ends).
• The second option describes prophase (DNA condensation, nuclear membrane breakdown).
• The third option describes anaphase (sister chromatids separating and moving to poles).
• The fourth option: In metaphase, chromosomes align at the cell's equatorial plate (middle), which is its defining event.

Answer:

D. Chromosomes line up in the middle of the cell.