Cell Division Cell Division Mitosis Mitosis Reasons for Mitosis - PowerPoint PPT Presentation

Cell Division Cell Division Mitosis Mitosis

Reasons for Mitosis Reasons for Mitosis There are three main reasons There are three main reasons A. growth growth A. B. repair/healing repair/healing B. C. asexual reproduction asexual reproduction C.

Cell Division by mitosis Cell Division by mitosis  Some cells divide Some cells divide constantly: cells in the constantly: cells in the embryo, skin cells, gut embryo, skin cells, gut lining cells, etc. lining cells, etc. 7 week old embryo Intestinal Cell Epithelial Cell

Cell Division Cell Division  Other cells divide rarely or Other cells divide rarely or never. never. Spinal Cord Cell- Nerve cell Cardiac Cell Brain Cell – Nerve cell (Heart Muscle)

Cell Division Cell Division Pancreatic  2 kinds of cell division: 2 kinds of cell division: cells  1. Mitosis: division of somatic cells 1. Mitosis: division of somatic cells  2. Meiosis: creation of new sex cells 2. Meiosis: creation of new sex cells Sperm cells Human egg cell

Cell Division Vocabulary Cell Division Vocabulary  Somatic cell Somatic cell – a body cell; a cell whose – a body cell; a cell whose genes will not be passed on to future genes will not be passed on to future generations. generations.  Germ cell Germ cell - a cell that is destined to - a cell that is destined to become a gamete (egg or sperm); a cell become a gamete (egg or sperm); a cell whose genes can be passed on to whose genes can be passed on to future generations future generations

Cell Division Vocabulary Cell Division Vocabulary  diploid (2N) diploid (2N) – a cell with 2 chromosome – a cell with 2 chromosome sets in each of its cells; all body sets in each of its cells; all body (somatic) cells (somatic) cells  haploid (N) haploid (N) – a cell with 1 chromosome – a cell with 1 chromosome set in each of its cells; all gametes set in each of its cells; all gametes (sperm, eggs) (sperm, eggs)

Characteristics of Characteristics of Mitosis Mitosis  A A dipl oid cel l w il l g iv e r ise t o a dipl oid cel l dipl oid cel l w il l g iv e r ise t o a dipl oid cel l  C C hr omosome number r ema ins t he sa me hr omosome number r ema ins t he sa me  T T he DN A r ema ins ident ica l l y t he sa me he DN A r ema ins ident ica l l y t he sa me  O O ne cel l ( 2N ) g iv es r ise t o t w o cel l s ( 2N ) ne cel l ( 2N ) g iv es r ise t o t w o cel l s ( 2N )

Cell Cycle Cell Cycle  A typical cell goes A typical cell goes through a process through a process INTERPHASE of growth, of growth, development, and development, and reproduction called reproduction called the cell cycle. the cell cycle.  Most of the cycle is Most of the cycle is called interphase. called interphase.

Cell Cycle Cell Cycle  The longest The longest phase in the phase in the cell cycle is cell cycle is interphase. interphase.  The 3 stages of The 3 stages of interphase are interphase are called G 1 , S, called G 1 , S, and G 2 . and G 2 .

Cell Division Cell Division  All living cells come from other living All living cells come from other living cells. cells.  During mitosis, the nucleus of the cell During mitosis, the nucleus of the cell divides, forming two nuclei with divides, forming two nuclei with identical genetic information. identical genetic information.

Mitosis Mitosis  Mitosis produces Mitosis produces two genetically two genetically identical cells. identical cells.  Mitosis is referred Mitosis is referred to in the following to in the following stages: prophase, stages: prophase, metaphase, metaphase, anaphase, and anaphase, and telophase. telophase.

Prophase Prophase  In prophase, the cell begins the process of In prophase, the cell begins the process of division. division.  The chromosomes condense. The chromosomes condense.

duplicated chromosom e chromatin

Prophase Prophase  Nuclear envelope disappears. Nuclear envelope disappears.

Prophase Prophase  Centrioles Centrioles migrate to migrate to opposite poles of opposite poles of the cell. the cell.  Asters and Asters and spindle fibers spindle fibers form. form. Aster and the mitotic apparatus in an animal cell

Draw Prophase Draw Prophase

Prophase Prophase Spindle fibers Aster Centriole Sister chromatids Centromere

Metaphase Metaphase  The The Centriole chromosomes chromosomes line up at the line up at the Spindle fibers Metaphase equator of the cell equator of the cell plate (metaphase plate), (metaphase plate), with the centrioles with the centrioles at opposite ends at opposite ends and the spindle and the spindle fibers attached to fibers attached to the centromeres. the centromeres. Centriole

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Anaphase Anaphase  In anaphase, the In anaphase, the centromeres divide. centromeres divide.  At this point, each At this point, each chromosome goes chromosome goes from having 2 sister from having 2 sister chromatids to being chromatids to being 2 separate 2 separate chromosomes chromosomes

Anaphase Anaphase  The spindle fibers The spindle fibers contract and the contract and the chromosomes are chromosomes are pulled to opposite pulled to opposite poles. poles.

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Telophase Telophase  In telophase the In telophase the nucleus actually nucleus actually divides. divides.  The chromosomes are The chromosomes are at the poles of the cell. at the poles of the cell.  The nuclear envelope The nuclear envelope re-forms around the re-forms around the two sets of two sets of chromosomes. chromosomes.

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Cytokinesis Cytokinesis  The division of the The division of the cytoplasm. cytoplasm.  In animal cells, a In animal cells, a Cleavage Furrow Cleavage Furrow forms and forms and separates Daughter separates Daughter Cells Cells Cleavage furrow in a dividing frog cell.

Cytokinesis Cytokinesis  In plant cells, a Cell Plate In plant cells, a Cell Plate forms and separates forms and separates Daughter Cells. Daughter Cells. Cell Plate forming

ANIMAL VS. PLANT MITOSIS ANIMAL VS. PLANT MITOSIS  ANIMAL CELL  PLANT CELL ANIMAL CELL PLANT CELL  Centriole and Centriole and  No visible No visible aster present centriole or aster present centriole or aster aster  Daughter cells Daughter cells separated by  Daughter cells Daughter cells separated by cleavage furrow separated by cleavage furrow separated by cell plate cell plate

M it osis: C a n y ou na me t he st a ges? M it osis: C a n y ou na me t he st a ges? 1 2 3 4 5

M it osis: C a n y ou na me t he st a ges? M it osis: C a n y ou na me t he st a ges? Prophase 2 3 4 5

M it osis: C a n y ou na me t he st a ges? M it osis: C a n y ou na me t he st a ges? Prophase Metaphase 3 4 5

M it osis: C a n y ou na me t he st a ges? M it osis: C a n y ou na me t he st a ges? Prophase Metaphase Anaphase 4 5

M it osis: C a n y ou na me t he st a ges? M it osis: C a n y ou na me t he st a ges? Prophase Metaphase Anaphase Telophase 5

M it osis: C a n y ou na me t he st a ges? M it osis: C a n y ou na me t he st a ges? Prophase Metaphase Anaphase Telophase Cytokinesis

 P P ha ses of cel l cy cl e- IP M A T C ha ses of cel l cy cl e- IP M A T C Interphase Cytokinesis

 Phases of cell cycle - IPMATC Phases of cell cycle - IPMATC I mportant I mpatient P eople P eople M ust M ay A nalyze A ttack T asks T eachers C orrectly C onstantly