* Centrioles are small, cylindrical structures that are involved in the formation of the spindle fibers that separate the chromosomes during mitosis. They are duplicated during the S phase of interphase, the period before mitosis.
* Chromosomes are structures that carry the genetic information of the cell. Each chromosome is composed of a single, long DNA molecule that is tightly wound around proteins. Before mitosis, the chromosomes are duplicated, creating two identical copies of each chromosome. These copies are held together at a structure called the centromere.
During mitosis, the spindle fibers attach to the centromeres of the chromosomes and pull the sister chromatids (the two copies of each chromosome) apart, ensuring that each daughter cell receives a complete set of chromosomes.
