Cell-Cycle-and-Stage-of-Mitosis_compressed

Page 3: Introduction to Cells

  • Definition of a Cell: Basic structural, functional, and reproductive unit of all organisms

Page 4: Overview of the Cell Cycle

  • Definition: A series of events that occurs in a cell as it grows and divides

Page 5: Structure of the Cell Cycle

  • Divided into Two Main Stages:

    • I. Interphase

    • II. M Phase (Mitosis)

Page 6: Details of the Cell Cycle

  • Interphase:

    • Preparation and growth for M Phase

    • Stages: G1, S, G2

  • M Phase:

    • Actual process of cell division

Page 7: Interphase Stages

  • Stage 1: G1 (Gap 1) Phase

    • Longest phase

    • Rapid growth until normal cell size is attained

    • Organelles formed; proteins produced (e.g., enzymes for S phase)

    • Non-dividing cells (e.g., muscle, nerve) remain in this stage

Page 8: S Phase (Synthesis Phase)

  • Key Process:

    • Replication of DNA occurs

    • Each chromosome consists of two sister chromatids attached at the centromere

Page 9: G2 Phase

  • Preparation for Cell Division:

    • Assembly of proteins like microtubules for chromosome movement during division

Page 10: M Phase (Mitosis/Meiosis)

  • Division of the cell:

    • Karyokinesis: Division of the nucleus

    • Cytokinesis: Division of the cytoplasm

Page 11: Introduction to Mitosis

  • Definition: A type of cell division where the nucleus divides into two identical nuclei

  • Resulting daughter cells have the same number of chromosomes (e.g., body cells)

    • Example: Body cell with 46 chromosomes produces two daughter cells, each with 46 chromosomes

Page 12: Stages of Mitosis

  • Stages known as PMAT:

    • Prophase

    • Metaphase

    • Anaphase

    • Telophase

Page 13: Stages of Mitosis - Prophase

  • Key Events:

    • Chromatin condenses into chromosomes

    • Nuclear membrane dissolves

    • Spindle fibers form

    • Centrioles migrate to opposite poles

    • Nucleolus disappears as starting signal

Page 14: Stages of Mitosis - Metaphase

  • Key Events:

    • Chromosomes align at the center (metaphase plate)

    • Spindle fibers connect to kinetochores on the centromeres

Page 15: Stages of Mitosis - Anaphase

  • Key Events:

    • Sister chromatids segregate

    • Chromosomes move towards opposite poles via spindle fiber shortening

Page 16: Stages of Mitosis - Telophase

  • Key Events:

    • Chromosomes decondense

    • Nuclear membranes reform at both poles

    • Spindle fibers disappear

    • Completion of karyokinesis

Page 17: Cytokinesis

  • Definitions:

    • Karyokinesis: Division of the nucleus

    • Cytokinesis: Division of the cytoplasm

  • Cytokinesis in Animal Cells:

    • Begins at the cell exterior and moves inward (cleavage furrow)

  • Cytokinesis in Plant Cells:

    • Starts in the middle and moves outward (cell plate formation)

Page 18: Conclusion

  • Questions invited

Page 19: Activity Instruction

  • Task: On paper, draw, label, and describe each stage of mitosis

  • Format:

    • Phase of Mitosis: __________

    • Description: _______________

Page 20: Acknowledgments

  • Expression of thanks.