NEET BIOLOGY

Detailed explanation-1: -Metaphase. During metaphase, spindle fibers attach to the centromere of each pair of sister chromatids (see Figure below). The sister chromatids line up at the equator, or center, of the cell. This is also known as the metaphase plate.

Detailed explanation-2: -Metaphase follows prophase. During metaphase, the chromosomes align in the center of the cell at the equatorial plate and the spindle fibers attach to the centromeres of the chromosomes.

Detailed explanation-3: -Anaphase I: In anaphase I, the attachment of the spindle fibers is complete. The homologous chromosomes are pulled apart and move towards opposite ends of the cell. Do not confuse this with the pulling apart of sister chromatids!

Detailed explanation-4: -The first step of cell division is prophase, during which the nucleus dissolves and the chromosomes begin migration to the midline of the cell. (Some biology textbooks insert a phase called “prometaphase” at this point.)

Detailed explanation-5: -During metaphase, the kinetochore microtubules pull the sister chromatids back and forth until they align along the equator of the cell, called the equatorial plane.