how are elephants able to grow to such a large size?

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

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