Cell Division

Mitosis

Mitosis

Prophase 1

• DNA coils tightly.

  • Chromosomes are thus shortened and thickened.

• Microtubules organize into a spindle.

• Nuclear membrane breaks down.

• Nucleolus is no longer visible.

Metaphase 1

• Chromosomes attach to the spindle at their centromeres.

  • Align along the cell
    R

Anaphase 1

• Plasma membrane indents at the center.

• Centromeres divide, which releases the tension.

• Chromatids separate and become independent chromosomes.

  • Move to opposite ends of the cell.

• During this very brief phase, a cell fleetingly contains twice the normal number of chromosomes.

Telophase 1

• The cell looks like a dumbbell with a set of chromosomes at each end.

• Spindle falls apart.

• Nucleoli and membranes around the nuclei re-form at each end of the elongated cell.

• Division of the genetic material is now complete.

Cytokinesis

• Cytoplasmic division occurs after nuclear division is complete.

• Organelles and macromolecules are distributed between the two daughter cells.

• Microfilament band contracts, separating the two cells.