Centromeres split apart during what?
Centromeres are specialized regions of chromosomes that play a critical role
in cell division. Specifically, they are responsible for dividing the genetic
material between the daughter cells during mitosis and meiosis.
During mitosis, the centromeres split apart during the metaphase stage of cell
division. This occurs when the spindle fibers, which are microtubules that help
separate the chromosomes, attach themselves to the kinetochores (protein
structures found on centromeres) and begin to pull the chromosomes towards
opposite poles of the cell. As the chromosomes move apart, the centromeres
split apart, allowing each daughter cell to receive an equal copy of the genetic
material.
The same process occurs during meiosis, which is a specialized form of cell
division that produces gametes (e.g. sperm and egg cells). However, during
meiosis, the centromeres split apart twice - once during the first stage of
meiosis (meiosis I) and again during the second stage (meiosis II). This
results in the production of four genetically diverse daughter cells, each with
half the number of chromosomes of the original parent cell.
In summary, centromeres split apart during both mitosis and meiosis, as part
of the process of dividing genetic material between daughter cells. This
process is essential for the maintenance of genetic stability and the production
of new cells.
References:
- Alberts B, Johnson A, Lewis J, et al. Molecular Biology of the Cell. 4th edition. New York:
Garland Science; 2002. Centrosomes and the Formation of Mitotic Spindles. Available from:
https://www.ncbi.nlm.nih.gov/books/NBK26867/
- Lodish H, Berk A, Zipursky SL, et al. Molecular Cell Biology. 4th edition. New York: W. H.
Freeman; 2000. Mitosis: The Mechanics of Cell Division. Available from:
https://www.ncbi.nlm.nih.gov/books/NBK21506/