MitosisMitosis

MitosisMitosis

The process of cell reproductionThe process of cell reproduction It is the basis for growth and tissue repairIt is the basis for growth and tissue repair

Takes place in regular body cells (Takes place in regular body cells (somatic somatic cellscells))

The physical division of one parent cell into The physical division of one parent cell into two daughter cellstwo daughter cells Parent cell provides each daughter cell with Parent cell provides each daughter cell with

enough DNA (hereditary information) and enough DNA (hereditary information) and cytoplasm (and organelles) to properly cytoplasm (and organelles) to properly function on their ownfunction on their own

From one to TwoFrom one to Two

The Cell CycleThe Cell Cycle Each cell undergoes a “regular” cell cycle, Each cell undergoes a “regular” cell cycle,

that starts from the moment they are that starts from the moment they are createdcreated

The cycle is mostly made up of the phase: The cycle is mostly made up of the phase: interphase interphase Dedicated to normal cell functions, and cell Dedicated to normal cell functions, and cell

growth and DNA replication in preparation for growth and DNA replication in preparation for mitosismitosis

Mitosis only plays a small partMitosis only plays a small part

Phases of the Cell CyclePhases of the Cell Cycle

InterphaseInterphase ProphaseProphase MetaphaseMetaphase AnaphaseAnaphase TelophaseTelophase CytokinesisCytokinesis

Mitosis

InterphaseInterphase

Longest stage in a cells lifeLongest stage in a cells life Time spent between divisionsTime spent between divisions Preparation for divisionPreparation for division

Replication of all the necessary materialsReplication of all the necessary materials

InterphaseInterphase3 phases of Interphase3 phases of Interphase

G1: Growth phase G1: Growth phase (duplication of cell (duplication of cell contents, excluding contents, excluding chromosomes)chromosomes)

S: Synthesis phase S: Synthesis phase (duplication of each of (duplication of each of the 46 chromosomes)the 46 chromosomes)

G2: Check phase (cell G2: Check phase (cell checks the duplicated checks the duplicated chromosomes for chromosomes for errors before errors before proceeding to division)proceeding to division)

ChromosomesChromosomes

Mitosis: ProphaseMitosis: Prophase First phaseFirst phase1. The nucleus disappears1. The nucleus disappears2. The nuclear membrane 2. The nuclear membrane

breaks apartbreaks apart3. The chromosomes become 3. The chromosomes become

visiblevisible4. 4. The spindle apparatus forms

and attaches to the centromeres of the chromosomes

Mitosis: MetaphaseMitosis: Metaphase

Nuclear membrane now Nuclear membrane now completely gonecompletely gone

Duplicated Duplicated chromosomes align at chromosomes align at the center of the cell the center of the cell (along the cells equator)(along the cells equator)

Mitosis: AnaphaseMitosis: Anaphase

The separation of the The separation of the diploid set of diploid set of chromosomes chromosomes (separation of the sister (separation of the sister chromatids)chromatids)

The are pulled to The are pulled to opposite poles of the opposite poles of the cell by the spindle cell by the spindle fibresfibres

Mitosis: TelophaseMitosis: Telophase

Begins when the Begins when the chromatids arrive at chromatids arrive at the opposite polesthe opposite poles

Nuclear membrane Nuclear membrane and nucleoli and nucleoli (nucleus) reform(nucleus) reform

Chromasomes Chromasomes uncondenseuncondense

CytokinesisCytokinesis The cytoplasmic divisionThe cytoplasmic division The cytoplasm, organelles, and nuclear

material are evenly split and two new cells are formed.

Cleavage of the cellCleavage of the cell

Final ProductFinal Product

At the end of At the end of mitosis, the mitosis, the two products two products are called are called daughter daughter cells. They cells. They are identical, are identical, each with 46 each with 46 chromosomeschromosomes