Cell Division. Mitosis – Occurs in BODY cells only!! Every cell must first copy its genetic...

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

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

Cell Division. Mitosis – Occurs in BODY cells only!! Every cell must first copy its genetic...

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