Cell division (mitotic phase)

Describe the prophase

• Chromosomes condense and become visible

• Spindle fibers emerge from the centrosomes

• Nuclear envelope breaks down

• Nucleolus disappears

• Chromosomes continue to condense

• Kinetochores appear at the centromeres

• Mitotic spindle microtubules attach to kinetochores

• Centrosomes move toward opposite poles

Describe the Metaphase

• Mitotic spindle is fully developed, centrosomes are at opposite poles of the cell

• Chromosomes are lined up at the metaphase plate

• Each sister chromatid is attached to a spindle fiber originating from opposite poles

Describe the Anaphase

• Cohesion proteins binding the sister chromatids together break down

• Sister chromatids (now called chromosomes) are pulled toward opposite poles

• Non-kinetochore spindle fibers lengthen, elongating the cell

Describe the Telophase

• Chromosomes arrive at opposite poles and begin to decondense

• Nuclear envelop material surrounds each set of chromosomes

• The mitotic spindle breaks down

Describe Cytokinesis

• Animal cells: a cleavage furrow separates the daughter cells

• Plant cells: a cell plate separates the daughter cells