Phases of the Cell Cycle • Interphase • Mitosis – Prophase – Metaphase – Anaphase – Telophase • Cytokinesis
Interphase • • Longest phase of the cell cycle Cell grows to mature size Replicates DNA Prepares for division
Mitosis • Mitosis is the process of cell division. • Mitosis is split into four separate phases.
Mitosis: Prophase • The chromatin in the nucleus condenses to form chromosomes. • Pairs of centrioles move to opposite sides of the nucleus. • Spindle fibers form a bridge between the ends of the cell. • Nuclear envelope breaks down.
Mitosis: Metaphase • Chromosomes line up along the center of the cell. • Each chromosome attaches to a spindle fiber at its centromere.
Mitosis: Anaphase • Centromeres split. • Two chromatids separate. • One chromatid is drawn by its spindle fiber to one end of the cell, the other moves to the opposite end. • The cell stretches out as opposite ends are pushed apart.
Mitosis: Telophase • Chromosomes spread out and lose rod-like appearance. • New nuclear envelope forms around each region of chromosomes.
Cytokinesis • Cell membrane pinches in around middle of the cell, cytoplasm splits. • Two new cells are formed. • Each cell ends up with identical set of chromosomes and about half the organelles. • In plants because of the cell wall, a cell plate is used during cytokinesis.