1 / 15

Cell division

Cell division . Biology 106. Outline. - Types of cell division - Mitosis Phases of mitosis Diagram shows how mitosis works - Meiosis Phases of meiosis Diagram shows how meiosis works. Mitosis. - This type of cell division allows multicellular organism to grow and repair damage tissue.

vidar
Download Presentation

Cell division

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Cell division Biology 106

  2. Outline • - Types of cell division • - Mitosis • Phases of mitosis • Diagram shows how mitosis works • - Meiosis • Phases of meiosis • Diagram shows how meiosis works

  3. Mitosis • - This type of cell division allows multicellular organism to grow and repair damage tissue. • - Mitosis produce two daughter cells that are identical to the parent cell.

  4. Mitosis subdivided into 5 phases • Interphase: takes about 90% of the cell cycle • The cell can grow and copy its chromosomes. • 1- Prophase • 2-Prometaphase • 3-Metaphase • 4-Anaphase • 5-Telophase • Cytokinasis

  5. 1- Prophase -Chromosome condensed and become shorter -Nucleoli disappear -The centrosomes duplicate and mitotic spindle fibers begin to form. • 2-Prometaphase -The nuclear envelope fragmented. -The chromosomes become shorter and attached to spindle fibers.

  6. 3-Metaphase • The centrosomes are at the opposite poles of the cell. • The chromosomes arranged on the metaphase plate. • 4-Anaphase • Tow sister chromatids are separated. • Chromatids moving toward the opposite poles

  7. 5-Telophase • Tow daughter nuclei are formed • Nuclear envelope arises • Chromosomes become less condensed. • Spindle fibers disappear • Cytokinesis: Cytoplasm begins to divide in order to give tow daughter cells that have the same number of chromosomes and genetically identical to the mother cells.

  8. Mitosis

  9. Meiosis • Enable the organisms to reproduce sexually. • Occurs only in the gonad (Ovary & testis) • Gives rise to male and female gametes. • Involves tow nuclear division producing 4 daughter cells.

  10. Meiosis Meiosis I • (Reduction division) 1- Prophase I 2- metaphase I 3- Anaphase I 4- Telophase I • Cytokinesis Meiosis II • (Mitotic division) - See mitotic division

  11. Meiosis I(Reduction division) 1- Prophase I A)Chromosomes condensed & become shorter. B)Disappearance of nucleolus & nuclear envelope C)Formation of spindle fibers D)Homologues pairs of chrmosomes are united together E)Crossing over occures….

  12. 2- metaphase I • Pair of homologues chromosomes arrange at equator (Metaphase plate) • Chromosomes attach to the spindle fibers. • 3- Anaphase I - Separation of homologues pairs of chrmosomes. • 4- Telophase I • Nucleolus & nuclear membranes reappear. • Spindle fiber disappear.

  13. Cytokinesis : • Occurs by dividing the cell into tow daughter cells. • The producing cells have half chromosomal of mother cells and differ genetically from them

  14. Mitosis vs meiosis

More Related