Cell Division pg. 67Cell Division pg. 67

• Cell life cycle - changes a cell goes through from when formed to division

1. Interphase - cell grows, metabolic activities

2. Cell Division - cell reproduces

• Cell life cycle - changes a cell goes through from when formed to division

1. Interphase - cell grows, metabolic activities

2. Cell Division - cell reproduces

Cell DivisionCell Division• DNA replicates before Mitosis

• Mitosis• division of the nucleus• Forms two daughter nuclei

• Cytokinesis - division of cytoplasm, begins when mitosis is almost completed

• DNA replicates before Mitosis

• Mitosis• division of the nucleus• Forms two daughter nuclei

• Cytokinesis - division of cytoplasm, begins when mitosis is almost completed

Cell DivisionCell Division

Prophase1. chromatin coil and

shorten to chromosomes, 2 chromatids, held together by centromere

2. Centrioles separate and move to opposite sides

3. Mitotic spindle forms, scaffolding

4. End - nuclear membrane and nuclei broken down, attach to spindle fibers

Prophase1. chromatin coil and

shorten to chromosomes, 2 chromatids, held together by centromere

2. Centrioles separate and move to opposite sides

3. Mitotic spindle forms, scaffolding

4. End - nuclear membrane and nuclei broken down, attach to spindle fibers

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Cell DivisionCell Division

Metaphase1. Sister chromatids

align midway between centrioles

Metaphase1. Sister chromatids

align midway between centrioles

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Cell DivisionCell Division

Anaphase1. Centromeres split2. Chromatids move

slowly apart, become chromosomes

3. Finished when chromosomes have stopped

Anaphase1. Centromeres split2. Chromatids move

slowly apart, become chromosomes

3. Finished when chromosomes have stopped

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Cell DivisionCell Division

Telophase1. Reverse prophase2. Chromosomes uncoil,

become chromatin3. Spindle breaks down4. Nuclear membrane

forms around mass of chromatin

5. Nuclei appear in each daughter nuclei

Telophase1. Reverse prophase2. Chromosomes uncoil,

become chromatin3. Spindle breaks down4. Nuclear membrane

forms around mass of chromatin

5. Nuclei appear in each daughter nuclei

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Cell DivisionCell Division

Cytokinesis1. Division of

cytoplasm2. Late anaphase-

telophase3. Cleavage furrow -

midline of spindle, pinches cytoplasmic mass into two parts

Cytokinesis1. Division of

cytoplasm2. Late anaphase-

telophase3. Cleavage furrow -

midline of spindle, pinches cytoplasmic mass into two parts

QuickTime™ and a decompressor

are needed to see this picture.