Kinetochore is a protein structure that is formed on the centromere of a chromatid during mitosis and meiosis. It plays a crucial role in the proper segregation of chromosomes during cell division.

Formation of Kinetochore:
The formation of kinetochore involves the following steps:

1. Centromere Formation: During the S-phase of the cell cycle, the DNA replicates and the two identical chromatids are joined together at the centromere region.

2. Chromosome Condensation: As the cell prepares for mitosis, the chromosomes undergo condensation, becoming more compact and visible under a microscope.

3. Kinetochore Formation: As the chromosomes condense, the kinetochore proteins are assembled at the centromere region. These proteins form a complex structure that attaches to spindle fibers during cell division.

4. Spindle Fiber Attachment: The spindle fibers, which are made up of microtubules, attach to the kinetochore proteins at the centromere region. This attachment allows the spindle fibers to pull the chromosomes apart during cell division.

Functions of Kinetochore:
The kinetochore plays several important roles during cell division, including:

1. Chromosome Segregation: The kinetochore helps to ensure that each chromatid is properly aligned and separated during cell division, resulting in the formation of two identical daughter cells.

2. Error Correction: The kinetochore can detect and correct errors in chromosome alignment, ensuring that the correct number of chromosomes is passed on to each daughter cell.

3. Cell Cycle Control: The kinetochore is also involved in regulating the timing of cell division, ensuring that it only occurs after the cell has completed all necessary processes, such as DNA replication.

In conclusion, the kinetochore is a complex protein structure that plays a crucial role in chromosome segregation during cell division. Its formation involves the assembly of kinetochore proteins at the centromere region, followed by spindle fiber attachment. The kinetochore also performs important functions such as error correction and cell cycle control.