Interphase
-Not part of mitosis
Three distinct periods of interphase
G1-The centrioles begin replicating
S- DNA is replicated
G2- Final preparations for mitosis are completes and centrioles finish replicating
Prophase- Early prophase
-Chromatin condenses forming barlike chromosomes
-Each duplicated chromosome consists of two identical threads called sister chromatids, held together at the centromere
-As chromosomes appear, the nucleoli disappear, and the two centrosomes separate from one another
-Centrosomes allow for the growth of mitotic spindles
-Asters "stars" extend from the centrosome matrix
Late prophase
-Nuclear envelope breaks up, allowing spindle to interact with the chromosomes
-Spindle fibers attach to kinetochores
-Kinetochores pull on chromosomes, pulling them further apart
Metaphase
-Two centrosomes are at opposite poles of the cell
-The chromosomes align at the equator (metaphase plate)
-Enzymes act to separate the chromatids from each other
Anaphase
-Shortest phase
-Each chromatid splits and each become its own chromosome
-The kinetochores pull each chromosome toward the pole it faces
Telophase
-A new nuclear envelope forms around each chromatin mass
-Nucleoli reappear within the nuclei, and the spindle breaks down and disappears
-End of mitosis
Cytokinesis
-A contractile ring of actin microfilaments forms the cleavage furrow and pinches the cell apart