CELL CYCLE pt.2.pptx not all mine but I would like to share.

CELL CYCLE pt.2.pptx not all mine but I would like to share.

1. THE CELL CYCLE AND CELL DIVISION

2. M phase G 2 phase S phase G 1 phase CELL CYCLE

3. CELL CYCLE - Interphase Three (3) phases: G 1 Phase Cell increases in size S Phase Replication of DNA Two sister strands of DNA called chromatids are produced G 2 Phase Organelles double New cytoplasm forms All other structures needed for mitosis form

4. M phase G 2 phase S phase G 1 phase

5. CELL DIVISION

6. CELL DIVISION - takes up 20% of the cell life’s span All the regular activities of the cells come to a stop when it starts dividing. The nucleus expands during the cell division. This is also the period when the parent cell completes the set of genetic material that is transferred to the offspring.

7. CELL DIVISION Meiosis – reproductive cells - sex gametes Two Kinds of cell division Mitosis – division of body cells pertaining to epithelial, bone, blood, and muscle cells and etc.

8. MITOSIS - The division of body cells. - It happens in all types of cells, except gametes. - mitosis takes up about 2 out of 24 hours, about 20% of the cell’s life cycle.

9. MITOSIS - Divided into 4 distinguishable stages: prophase, metaphase, anaphase, and telophase, PMAT

10. - Chromatids connected by a centromere . Centrioles Spindle made of microtubules First and longest stage of mitosis. Taking up about half of the time of the entire mitotic cycle. It begins with a cell which has a diploid number of chromosomes. PROPHASE

11. - Chromatids connected by a centromere . Centrioles Spindle made of microtubules Chromatids condense becoming chromosomes Nucleolus disappears Centrioles separate and start moving to opposite ends of the cell Spindle begins to form PROPHASE

12. PROMETAPHASE The nuclear membrane fragments and the microtubules invade the nuclear area Centrioles have moved to the opposite poles The spindle is completely formed centrioles Microtubules form a complete spindle chromatids centrioles

13. Metaphase Second and shortest stage of mitosis. Chromosomes become more conspicuous, emerging to be dark and thick elongated boudes connected to the spindle fibers. Centriole s Chromosomes Spindle composed of microtubules

14. Metaphase Centriole s Chromosomes Spindle composed of microtubules Under the directions of the spindle apparatus, the chromosomes move towards the cell’s equatorial plate known as the metaphase plate. Centrioles move at polar ends and projects spindle fibers to connect each chromosome

15. Anaphase The paired chromosomes (sister chromatids) separate. Separated chromatids move to opposite pole Partial division of cytoplasm begins Chromatids are being pulled to opposite sides of the cell . Shortening of the microtubules

16. Telophase Chromosomes are at the poles Chromosomes uncoil-turn chromatin Nuclear envelops reforms Spindle fiber disappear Nuclear membrane is returning

17. Karyokinesis The completion of telophase is indicated by karyokinesis . Complete division of the nucleus to form two daughter nuclei. It assures the equal distribution of the genetic materials between the newly-produced nuclei.

18. Cells return to interphase Cytokinesis: Occurs at the end of mitosis Animal cells: a cleavage furrow separates the daughter cells Plant cell : a cell plate separates the daughter cells Daughter cells are genetically identical