Stages of mitosis final project itp
- 1. Stages of Mitosis Kimberly J. Luper B.S. M.S.
- 2. Objectives Distinguish the difference between mitosis and meiosis. List the functions of mitosis Define the mitotic phase. Discuss and explain the four stages of mitosis. Define cytokinesis.
- 3. Mitosis v/s Meiosis • Mitosis is the duplication of the chromosomes in the nucleus and their separation into two identical sets in the process of somatic (“of the body”) cell division. • Meiosis is restricted to one purpose, the production of eggs and sperm.
- 4. Functions of Mitosis Growth of all tissues and organs after birth. Replacement of cells that die. Repair of damaged tissues.
- 5. Mitotic Phase The mitotic phase of the cell cycle consists of: Nuclear division (mitosis) Cytoplasmic division (cytokinesis) to form two identical cells.
- 6. Four Stages of Mitosis
- 7. Prophase Prophase is actually divided into two steps: 1. Early prophase 2. Late prophase
- 8. Early Prophase Centrioles (two pairs) “Aster rays” Nuclear envelope containing chromosomes.
- 9. Late Prophases Chromosome with two sisters chromatids Centromere Centrioles Spindle fibers /microtubules
- 13. Daughter cells
- 14. Cytokinesis Cytoplasmic division: contractile ring from cleavage furrow around the center of the cell, dividing cytoplasm into separate and equal portions.
- 15. WHY? Why is the mitotic phase or mitosis phase so important?
- 16. WHY? Cell division or mitosis helps the body to replace dead cells and repair damaged tissue. (Paper cuts to major surgery)
- 17. Check In PMAT
- 18. PMAT 1. Pro(before) phase: Chromatin fibers condense into paired chromatids; nucleus envelope disappears; each centrosome moves to an opposite pole of the cell. 2. Meta( after) phase: Centromeres of chromatid pairs line up at metaphase plate.
- 19. PMAT 3. Ana(apart) phase: Centromeres split; identical sets of chromosomes move to opposite poles of the cell. 4. Telo(end) phase: Nuclear envelopes and nucleoli reappear; chromosomes resume chromatin form; mitotic spindles disappear.
- 20. References Tortora, G.J. & Derrickson, B. (2012). Principles of Anatomy and Physiology (13th ed.). Hoboken, NJ: John Wiley & Sons. Martini, F.H., Nath, J.L. (2012) Fundamentals of Anatomy & Physiology (9th ed.). San Francisco, C.A. Pearson Education, Inc.
Editor's Notes
- #3: Distinguish the difference between mitosis and meiosis. List the functions of mitosis Define the mitotic phase. Discuss and explain the four stages of mitosis.
- #4: Mitosis is the duplication of the chromosomes in the nucleus and their separation into two identical sets in the process of somatic (“of the body”) cell division. Meiosis is restricted to one purpose, the production of eggs and sperm.
- #5: Mitosis serves all the other functions of cell division, including: Growth of all tissues and organs after birth. Replacement of cells that die. Repair of damaged tissues.
- #6: Mitosis separates the duplicated chromosomes of a cell into two identical nuclei. The term mitosis specifically refers to the division and duplication of the cell’s nucleus. The division of the cytoplasm to form two distinct new cells involves a separate but related process known as cytokinesis.
- #9: Prophase (PRŌ-fāz; pro, before) begins when the chromosomes coil so tightly they become visible as single structures under a light microscope. An array of microtubules called spindle fibers extends between the centriole pairs. Smaller microtubules called “astral rays” radiate into the cytoplasm
- #10: The nuclear envelope has disintegrated and the chromosomes with two sister chromatids appear. The mitotic spindle, composed of microtubules and proteins, forms in the cytoplasm. The two pair of centrioles move away from one another toward opposite ends of the cell due to the lengthening of the microtubules that form between them. Chromatin fibers become coiled into chromosomes with each chromosome having two chromatids joined at a centromere.
- #11: Metaphase(MET-a-fāz; meta, after) begins as the chromatids move to a narrow central zone called the metaphase plate. Metaphase ends when all the chromatids are aligned in the plane of the metaphase plate. The nuclear membrane disappears completely. The two pair of centrioles align at opposite poles of the cell. Chromosomes are held at the metaphase plate by the equal forces of the chromosomal microtubules pushing on the centromeres of the chromosomes.
- #12: Anaphase (AN-a-f z; ana-, apart) begins when the centromere of each chromatid pair splits and the chromatids separate. Once the paired sister chromatids separate from one another, each is considered a "full" chromosome. They are referred to as daughter chromosomes. The two daughter chromosomes are now pulled toward opposite ends of the cell along the chromosomal microtubules. 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.
- #13: During telophase (T¯L- -f z; telo-,end), each new cell prepares to return to the interphase state. The polar fibers continue to lengthen. Nuclei (plural form of nucleus) begin to form at opposite poles. The nuclear membranes reform, the nuclei enlarge, and the chromosomes gradually uncoil. After these changes, telophase/mitosis is largely complete and the genetic "contents" of one cell have been divided equally into two. This stage marks the end of mitosis.
- #14: Cytokinesis is the division of the cytoplasm into two daughter cells. Cytokinesis usually begins with the formation of a cleavage furrow and continues throughout telophase. The completion of cytokinesis marks the end of cell division.
- #20: Ana: Remember the Broadway musical “Annie?” She was an orphan and she was “apart” from her parents! Telo-phone your friends and tell them your are finished with mitosis!