Chapter 6, Sections 2 and 3

How do little elephants grow up to be BIG elephants?

WHY DO ANIMALS SHED THEIR SKIN?

The process of asexual reproduction begins

after a sperm fertilizes an egg.

Animated Mitosis Cycle

• Interphase

• Prophase

• Metaphase

• Anaphase

• Telophase & Cytokinesis

Process where nucleus of Cell Divides in two

Will have the same number and kinds of chromosomes as parent cell

Occurs in somatic cells=BODY cells (helps you grow and heal)

Every second in your body – 2 million RBC’s are made through mitosis!

Process by which the nucleus divides forming 2 distinct cells=DAUGHTER CELLS

Contains DNA Different organisms contain different

numbers of chromosomes called the DIPLOID NUMBER (2N) Humans=46 Dog=78 Lettuce=18 Goldfish=94

Made of chromatin Composed of DNA

and Protein 2 chromatids (pair)

attached by centromere=SISTER CHROMATIDS

DNA is copied in DNA Replication

INTERPHASE OCCURS BEFORE MITOSIS BEGINS

“INTERMISSION”

CELL MEMBRANENucleus

Cytoplasm

INTERPHASEINTERPHASE

Animal Cell Plant Cell

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

Prophase (Prepare): Chromosomes coil up and become visible in the nucleus. Nuclear membrane dissolves.

PROPHASE 1ST STEP IN MITOSIS

“PREPARE”

CentriolesSister chromatids

Spindle fibers

Animal Cell Plant Cell

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

Spindle fibers

Centrioles

Metaphase (middle): Chromosomes line up on equator, spindle fibers attach.

METAPHASE 2ND STEP IN MITOSIS

“MIDDLE”

Centrioles

Spindle fibers

Animal Cell Plant Cell

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

Anaphase (away): Centromeres divide, chromosomes separate and move toward poles.

ANAPHASE 3RD STEP IN MITOSIS

“AWAY”

Centrioles

Spindle fibers

Animal Cell Plant Cell

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

Telophase (tell me when it’s over): New nuclear membrane grows around each bundle of Chromosomes

TELOPHASE 4TH STEP IN MITOSIS

“TELL ME WHEN IT’S OVER”

NucleiNuclei

Chromatin

Animal Cell Plant Cell

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

Cytoplasm is divided in ½, taking organelles with it.

Cell Membrane encloses all. Animal cell: pinched in ½, called “cleavage

furrow.” Plant cell: Cell plate grows between the

two new cells. Mitosis video Thread of Life

CYTOKINESISOCCURS AFTER MITOSIS

2 DAUGHTER CELLS ARE FORMED .

with the exact same genetic info as the parent cell

Animal Mitosis -- Review

Interphase

                                              

              

Prophase

                                             

               

Metaphase

                                              

              

Anaphase

                                             

               

Telophase

                                              

              

Interphase

                                             

               

Plant Mitosis -- ReviewInterphase

                                                        

    

Prophase

                                                       

     

Metaphase

                                                        

    

Anaphase

                                                       

     

Telophase

                                                        

    

Interphase

                                                       

     

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http://www.cellsalive.com/mitosis.htm