The 4 stages of m !+0$!$

1. START Prophase Metaphase Telophase The 4 stages of m!+0$!$ Anaphase

3. Prophase • The chromosomes coil. • The nuclear membrane disintegrates. • The spindle apparatus forms. • The nucleolus disappears. • Each centrosome  of an animal cell contains two centrioles. Plant cells do not have centrioles but they do form spindle fibers. 

4. Photographs of Prophase Animal cell (early prophase) Plant (onion)

5. Metaphase • The nuclear membrane disappears completely. • In animal cells, the two pair of centrioles align at opposite poles of the cell. • Polar fibers continue to extend from the poles to the center of the cell. • Chromosomes move randomly until they attach to polar fibers from both sides of their centromeres. • Chromosomes align at the metaphase plate at right angles to the spindle poles. • Chromosomes are held at the metaphase plate by the equal forces of the polar fibers pushing on the centromeres of the chromosomes.

6. Photographs of Metaphase Animal cell (whitefish) Plant cell (onion)

7. Anaphase • The paired centromeres in each distinct chromosome begin to move apart. • Once the paired sister chromatids separate from one another, each is considered a "full" chromosome. They are referred to as daughter chromosomes. • Through the spindle apparatus, the daughter chromosomes move to the poles at opposite ends of the cell. • The daughter chromosomes migrate centromere first and the kinetochore fibers become shorter as the chromosomes near a pole. • In preparation for telophase, the two cell poles also move further apart during the course of anaphase. At the end of anaphase, each pole contains a complete compilation of chromosomes.

8. Photographs of Anaphase Early Anaphase Plant Cell (onion) Animal Anaphase Late Anaphase Plant Cell (onion)

9. Telophase • The polar fibers continue to lengthen. • Nuclei begin to form at opposite poles. • The nuclear envelopes of these nuclei are formed from remnant pieces of the parent cell's nuclear envelope and from pieces of the endomembrane system. • Nucleoli (plural form of nucleolus) also reappear. • Chromatin fibers of chromosomes uncoil. • After these changes, telophase/mitosis is largely complete and the genetic "contents" of one cell have been divided equally into two.

10. Photographs of Telophase Early Telophase Plant Cell (onion) Telophase Animal Cell (whitefish) Late Telophase Plant Cell (onion)

11. Glossary • Spindle Apparatus (spindle fibers)- A collection of microtubules attached to a centromere during mitosis and meiosis that are responsible for the movement of the chromosomes to opposite poles. • Centrosome- A small region of cytoplasm adjacent to the nucleus that contains the centrioles and serves to organize microtubules. • Centromere- a region of a chromosome where it attaches to a spindle fiber during mitosis and meiosis • Centriole- One of two cylindrical cellular structures that are composed of nine triplet microtubules and form the asters during mitosis. • Polar fibers-microtubules that make up the spindle fibers • Chromatids- Either of the two daughter strands of a replicated chromosome that are joined by a single centromere and separate during cell division to become individual chromosomes. • Kinetochore- Either of two submicroscopic attachment points for chromosomal microtubules, present on each centromere during the process of cell division b

12. Works Cited • http://student.ccbcmd.edu/~gkaiser/biotutorials/dna/mitosis/acprophaseB.html • http://biology.about.com/od/mitosis/ss/mitosisstep_3.htm • http://student.ccbcmd.edu/~gkaiser/biotutorials/dna/mitosis/acmetaphase.html • http://iknow.net/cell_div_education.html\ • http://www.cellsalive.com/mitosis.htm • http://student.ccbcmd.edu/~gkaiser/biotutorials/dna/mitosis/actelophase.html • http://www.biologycorner.com/resources/cell_cycle.jpg