The Cell Cycle and Mitosis

Mr. Meringolo

The Cell Cycle The cell cycle is divided into three stages: interphase, mitosis,

and cytokinesis. During the cell cycle, a parent cell divides into two cells. The new

cells are identical to the parent cell.

• Reproduction –Cell division is important for asexual reproduction, which involves only one parent organism. Sexual reproduction involves two parents. In single-celled organisms, the parent cell divides into two identical offspring.

Growth and Repair- One characteristic of all livings things is growth. Most growth occurs in organisms happens because cell division produces new cells.

Why do cells divide?

What happens to genetic material during cell division?

DNA- The genetic material in cells that contains the information that determines the traits that a living thing inherits.

DNA contains the instructions for an organisms growth, development, and activities.

Chromatin- A complex material consisting of DNA and proteins Chromatid- Two identical structures that develop after a

chromosome duplicates. Centromere- Holds the chromatids together.

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MitosisMitosis- The part of the cell cycle during which the nucleus divides

• Prokaryotes do not undergo mitosis because they do not have a nucleus

• Mitosis results in two identical nuclei that are identical to the original nucleus

• At the end of Mitosis, the cell has two identical sets of chromosomes intwo separate nuclei.

The Phases of Mitosis

• Interphase• Prophase• Metaphase• Anaphase• Telophase & Cytokinesis

Interphase occurs before mitosis begins

• The part of the cell cycle during which the cell is not dividing• During Interphase, the cell grows to about twice the size it was when it

was first produced and produces various organelles.• Changes that occur during interphase prepare a cell for division.• DNA is duplicated during interphase

CELL MEMBRANENucleus

Cytoplasm

InterphaseAnimal Cell Plant Cell

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

Prophase 1st step in Mitosis

• Mitosis begins (cell begins to divide)• During prophase, the chromatin in the nucleus of a cell

condenses and becomes visible and the membrane around the nucleus begins to break down.

ProphaseAnimal Cell Plant Cell

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

Spindle fibers

Centrioles

Metaphase 2nd step in Mitosis

• During Metaphase, chromosomes line up in the middle of the cell. The Centromeres of the chromosomes are the same distance from each side of the cell.

MetaphaseAnimal Cell Plant Cell

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

Anaphase 3rd step in Mitosis

• During Anaphase, the chromatids separate and they are pulled to opposite sides of the cell. Each side of the cell ends up with a complete set of chromosomes.

AnaphaseAnimal Cell Plant Cell

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

Telophase 4th step in Mitosis (Last Phase)

• The last phase of mitosis• A new nuclear membrane forms around each group of

chromosomes and the cell has two identical nuclei.• Chromosomes become less condensed• Cytokinesis begins during this phase

TelophaseAnimal Cell Plant Cell

Cytokinesisoccurs after Mitosis

• Cytokinesis- the division of the parent cell’s cytoplasm. Occurs when the cell membrane pinches inward towards the new nuclei until two complete cells are formed.

• Begins during the last step of mitosis

REMEMBER!InterphaseProphaseMetaphaseAnaphaseTelophaseCytokinesis

IPMATC

I Prefer Meatloaf At Tennis Camp

Cell Cycle

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