MITOSIS

Mitosis

The process of cell division which results in the production of two daughter cells

from a single parent cell.

The daughter cells are identical to one another and to the original parent

cell.

Mitosis can be divided into stages

• Interphase

• Prophase

• Metaphase

• Anaphase

• Telophase & Cytokinesis

InterphaseThe cell prepares for division

• Animal & Plant Cells – Nucleus clearly defined– Chromosomes not yet

visible

– DNA replicated– Organelles replicated– Cell increases in size

Interphase

Animal Cell Plant Cell

Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

ProphaseThe cell prepares for nuclear division

• Animal & Plant Cells– DNA packaged in to

chromosomes– Nuclear envelope

disappears

– Centrioles move to opposite sides of the cell

Prophase

Animal Cell Plant Cell

Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

MetaphaseThe cell prepares chromosomes for

division• Animal & Plant Cells

– Chromosomes line up at the center of the cell

– Spindle fibres attach to centromeres on the chromosomes

– Centrioles reach the opposite poles of the cell

Metaphase

Animal Cell Plant Cell

Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

AnaphaseThe chromosomes divide

• Animal & Plant Cells– Spindle fibers contract

and pull chromosomes apart

– ½ of each chromosome (called a chromatid) moves to each hemisphere

– Unattached spindle fibres push against each other or the sides of the cell, and it begins to elongate

Anaphase

Animal Cell Plant Cell

Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

TelophaseThe cytoplasm divides

• Animal Cell– DNA spreads out– 2 nuclei form– Contractile ring causes

a cleavage furrow to form the 2 new daughter cells

• Plant Cell– DNA spreads out– 2 nuclei form– Cell plate forms new

cell wall between the nuclei to form the 2 new daughter cells

Telophase

Animal Cell Plant Cell

Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

Mitosis Animations

Mitosis.exe

Mitosis Animation

Animal Mitosis -- Review

Interphase

                                              

              

Prophase

                                             

               

Metaphase

                                              

              

Anaphase

                                             

               

Telophase

                                              

              

Interphase

                                             

               

Plant Mitosis -- ReviewInterphase

                                                        

    

Prophase

                                                       

     

Metaphase

                                                        

    

Anaphase

                                                       

     

Telophase

                                                        

    

Interphase

                                                       

     

Summary of Mitosis• Prophase:

• Chromosomes condense• Nuclear envelope disappears• centrosomes move to opposite sides of the cell• Spindle forms and attaches to centromeres on the chromosomes

• Metaphase• Chromosomes lined up on equator of spindle• centrosomes at opposite ends of cell

• Anaphase• Centromeres divide: each 2-chromatid chromosome becomes

two 1-chromatid chromosomes• Chromosomes pulled to opposite poles by the spindle

• Telophase• Chromosomes de-condense• Nuclear envelope reappears• Cytokinesis: the cytoplasm is divided into 2 cells