Metaphase is a stage in mitosis where the chromosomes align along the equator of the cell. Each chromosome is made up of two identical sister chromatids that are connected at a point called the centromere.

Explanation:

• Chromosomes in Metaphase: During metaphase, the chromosomes become highly condensed and are visible under a microscope. They line up along the metaphase plate, which is an imaginary plane equidistant from the two poles of the cell.

• Sister Chromatids: Each chromosome consists of two identical sister chromatids that are held together by a centromere. Sister chromatids are exact copies of each other and contain the same genetic information.

• Two Sister Chromatids: During metaphase, each chromosome is made up of two sister chromatids that are still attached to each other at the centromere.

• Role of Spindle Fibers: The spindle fibers, which are microtubules that extend from the centrosomes at opposite poles of the cell, attach to the kinetochores of the sister chromatids. The kinetochores are protein structures located at the centromere that help to move the chromosomes during cell division.

• Chromosome Separation: Once the spindle fibers attach to the kinetochores, they pull the sister chromatids apart and towards opposite poles of the cell. This separation occurs during anaphase, which follows metaphase in the cell cycle.

In conclusion, during the metaphase stage of mitosis, each chromosome is made up of two identical sister chromatids that are joined together at the centromere. The spindle fibers attach to the kinetochores of the sister chromatids to align the chromosomes along the metaphase plate.