Kinetochore

Definition

A kinetochore is a protein complex assembled on the centromere of a chromosome during cell division. It plays a crucial role in chromosome segregation by attaching chromosomes to spindle microtubules.

5 Must Know Facts For Your Next Test

1. Kinetochores are essential for accurate chromosome alignment and segregation during mitosis and meiosis.
2. Each sister chromatid has its own kinetochore, which attaches to spindle fibers from opposite poles of the cell.
3. The kinetochore is composed of multiple proteins, including the Ndc80 complex, which directly interacts with microtubules.
4. Errors in kinetochore function can lead to aneuploidy, where cells have abnormal numbers of chromosomes.
5. Kinetochores are involved in the spindle assembly checkpoint, ensuring that all chromosomes are properly attached before proceeding with cell division.

Review Questions

• What role does the kinetochore play in cell division?
• How do kinetochores contribute to chromosome segregation?
• What could be the consequences of malfunctioning kinetochores?

Related terms

Centromere:

The region of a chromosome where the kinetochore forms and where sister chromatids are held together.

Spindle Microtubules: Structures composed of tubulin that attach to kinetochores and help segregate chromosomes during cell division.

Ndc80 Complex: A core component of the kinetochore that connects it to spindle microtubules.