Cell Division

Cell Division

• Mitosis – Occurs in BODY cells only!!

• Every cell must first copy its genetic information before cell division begins.

• ***Each daughter cell then gets an exact, complete copy of that information from the parent cell***

The Cell Cycle• Series of events

that cells go through as they grow and divide

• The “parent” cell grows, divides, and forms two “daughter” cells that each begin the cycle again

G2 phase

S phase

G1 phase

includes

is divided into is divided into

Cell Cycle

M phase (Mitosis)

Interphase

G1 phase S phase ProphaseG2 phase Metaphase TelophaseAnaphase

The Cell Cycle

Events of the Cell Cycle

• Interphase – time when cell isn’t dividing – can be long. Made up of 3 phases:– G1 – cells grow and create new proteins and

organelles– S – chromosomes replicated and make DNA– G2 – shortest of the three phases and

organelles required for cell division made– (Interphase is NOT part of Mitosis!)

Interphase

M-Phase: Mitosis

• Takes place quicker than Interphase, Occurs in somatic (body) cells only. Mitosis has four phases:– Prophase– Metaphase– Anaphase– Telophase

Prophase

• 1st and longest phase – chromosomes become visible. The centrioles separate and send spindles (tube-like structures) out to attach to chromosomes. Nuclear membrane breaks down.

Prophase

Metaphase

• 2nd and pretty short phase – chromosomes line up at center of cell

Metaphase

Anaphase

• 3rd phase – chromosomes separate and become individual chromosomes. They move to the poles of the spindle.

Anaphase

Telophase

• 4th phase – chromosomes begin to disperse into a tangle of dense material. Nuclear membrane re-forms around chromosomes and spindle breaks down.

Telophase

Cytokinesis

• At the end of Telophase, two nuclei are within cytoplasm of one cell. Cytokinesis divides the cytoplasm and occurs at the same time as Telophase

• Cytoplasm pinched in two to create ***two daughter cells genetically identical to one another***

Centrioles

Chromatin

Interphase

Nuclear envelope

Cytokinesis

Nuclear envelope reforming

Telophase

Anaphase

Individual chromosomes

Metaphase

Centriole

Spindle

CentrioleChromosomes

(paired chromatids)

Prophase

Centromere

Spindle forming

Mitosis and Cytokinesis

Centrioles

Chromatin

Interphase

Nuclear envelope

Cytokinesis

Nuclear envelope reforming

Telophase

Anaphase

Individual chromosomes

Metaphase

Centriole

Spindle

CentrioleChromosomes

(paired chromatids)

Prophase

Centromere

Spindle forming

Mitosis and Cytokinesis

Centrioles

Chromatin

Interphase

Nuclear envelope

Cytokinesis

Nuclear envelope reforming

Telophase

Anaphase

Individual chromosomes

Metaphase

Centriole

Spindle

CentrioleChromosomes

(paired chromatids)

Prophase

Centromere

Spindle forming

Mitosis and Cytokinesis

Centrioles

Chromatin

Interphase

Nuclear envelope

Cytokinesis

Nuclear envelope reforming

Telophase

Anaphase

Individual chromosomes

Metaphase

Centriole

Spindle

CentrioleChromosomes

(paired chromatids)

Prophase

Centromere

Spindle forming

Mitosis and Cytokinesis

Centrioles

Chromatin

Interphase

Nuclear envelope

Cytokinesis

Nuclear envelope reforming

Telophase

Anaphase

Individual chromosomes

Metaphase

Centriole

Spindle

CentrioleChromosomes

(paired chromatids)

Prophase

Centromere

Spindle forming

Mitosis and Cytokinesis

Centrioles

Chromatin

Interphase

Nuclear envelope

Cytokinesis

Nuclear envelope reforming

Telophase

Anaphase

Individual chromosomes

Metaphase

Centriole

Spindle

CentrioleChromosomes

(paired chromatids)

Prophase

Centromere

Spindle forming

Mitosis and Cytokinesis

Summary of Mitosis

• Occurs in body cells

• Makes 2 genetically identical cells with the same amount of chromosomes as parent cells

• PMAT – four stages of mitosis