Mitosis

Mitosis = nuclear division in which each daughter cell receives an exact copy of chromosomes in parent cell. 4 phases

Prophase

Nuclear envelope breaks down Centrosomes with centrioles move to opposite sides (poles) of cell Spindle fibers (made of microtubules) form from centrosomes

(spindle fibers) 2 types of spindle fibers - Kinetochore fibers – attach to kinetochore protein at centromere - Polar fibers – connected pole to pole

Metaphase Chromosomes line up in center of cell Spindle fibers attach to centromeres

Anaphase Spindle fibers shorten pulling sister chromatids to opposite sides of cell

Telophase Nuclear envelope re-forms around each new set of chromosomes Chromosomes spread out into chromatin Spindle fibers disappear

Cytokinesis = division of cytoplasm In animals – membrane pinches in b/t 2 new nuclei forming a cleavage furrow

In plants, cell plate forms in between 2 nuclei Cell plate develops into membrane New cell wall forms between 2 new membranes