how are elephants able to grow to such a large size?
TRANSCRIPT
How are elephants able to grow to such a large size?
The process of mitosis begins after a sperm
fertilizes an egg.
The Cell Cyclehttp://www.cellsalive.com/mitosis.htm
• Interphase
• Prophase
• Metaphase
• Anaphase
• Telophase
• Cytokinesis
• G1 (Gap 1) phase – Cells grow to a mature size.
• S (Synthesis) phase – DNA is copied. The number of chromosomes double.
• G2 (Gap 2) phase – Cells prepare for cell division.CELL MEMBRANENucleus
Cytoplasm
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
• Cell division begins. Chromatin condenses and changes form into rod shaped chromosomes.
• Centrioles appear and move to opposite poles.
• Spindle fibers form around the centrioles.• The nuclear membrane and the nucleolus
break down.
CentriolesSister chromatids
Spindle fibers
• Each chromosome was duplicated during the
• S phase of interphase. The two copies are now joined at the center. This area is called the centromere.
• Each half is referred to as a chromatid. The two together are sister chromatids.
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Spindle fibers
Chromosomes
• Sister chromatids attach to the spindle fibers at the centromere.
• Centrioles are attached to the other end of the spindle fiber.
• Sister chromatids move and line up at the middle or equator of the cell.
Centrioles
Spindle fibers
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
• Sister chromatids separate at the centromere and begin to move to the opposite poles.
Centrioles
Spindle fibers
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
• Two distinctive cells begin to form.• Two new nuclei form. • Chromosomes transform back to chromatin
(threads rather than rods).• Mitosis ends.
NucleiNuclei
Chromatin
Animal Cell Plant Cell
Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
• Cell membrane pinches in to create two daughter cells – each with its own nucleus with identical chromosomes.
• The pinched area is referred to as the cleavage furrow in animal cells.
• In plant cells, a cell plate forms instead to form a cell wall and separate the two new cells.
Animal Mitosis -- Review
Interphase
Prophase
Metaphase
Anaphase
Telophase
Interphase
Plant Mitosis -- ReviewInterphase
Prophase
Metaphase
Anaphase
Telophase
Interphase
IInterphasePProphaseMMetaphaseAAnaphaseTTelophaseCCytokinesis
IPMATIPMATCC
II PPlaylay MMore ore AAtt TThe he CCourtourt