“Exploring the Cell Cycle and Mitosis: Understanding How Cells Grow, Replicate DNA, and Divide Through Prophase, Metaphase, Anaphase, and Telophase to Produce Identical Daughter Cells for Growth, Repair, and Maintenance in Both Plant and Animal Organisms”

The cell cycle is the process by which cells grow and divide. About 90% of a cell’s life is spent in interphase (G₁, S, and G₂ phases), where it grows and duplicates DNA. The remaining 10% is mitosis, during which one cell divides to form two identical daughter cells. The stages of mitosis—prophase, metaphase, anaphase, and telophase (PMAT)—ensure that each new cell receives an identical set of chromosomes. In plant cells, a cell plate forms during cytokinesis, while animal cells form a cleavage furrow. Mitosis allows organisms to grow, repair tissues, and replace old cells.

1. CELL CYCLE & MITOSIS

2. Cell Cycle 90% of the cell cycle is in interphase, other 10% is mitosis (cellular division) Interphase composed of 3 phases: G1, S, and G2 G1 (Gap 1) phase : cellular growth and protein synthesis, in preparation for the S phase S (Synthesis) phase : DNA synthesis/replication of each chromosome in the cell, forms sister chromatids. G2 (Gap 2) phase : cellular growth as well as protein & lipid synthesis, in preparation for mitosis Ex. Synthesis of proteins used to form mitotic spindle

3. The Cell Cycle and Cancer

4. Mitosis Cellular division of a cell Makes exact copy of mother cell Produces 2 identical daughter cells Each product has same # of chromosomes Purpose of mitosis? To form a multicellular organism from a zygote To replace dead or lost cells, such as skin and red blood cells

5. Phases of Mitosis: (PMAT) + cytokinesis Prophase : chromosomes become visible, begin to condense Prometaphase : nuclear envelope disappears and chromosomes attach to mitotic spindle Metaphase : chromosomes line up at metaphase plate/equatorial plane Anaphase : sister chromatids separate by kinetochores Telophase : two daughter nuclei reform at the 2 poles Cytokinesis (division of the cytoplasm) occurs simultaneously

6. Time-Lapse: Mitosis

7. Interphase Prophase Metaphase Anaphase

8. Mitosis in plant cells differ from mitosis in animal cells Plant cells do not form centrioles during mitosis Plant cell walls are too rigid to form cleavage furrow Forms cell plate instead

9. cell plate Telophase/cytokinesis in a plant cell

10. cleavage furrow Telophase/cytokinesis in an animal cell

11. Some terms Gene : portion of DNA that encodes RNA and protein; determines your characteristics—freckles, height, eye color… Chromosomes : contain DNA and protein; compact way of carrying all genetic info Sister chromatids : copies of chromosomes joined together

12. CHROMOSOMES Humans Chromosomes

13. SOMATIC (Body) VS SEX CELLS (Gametes or Sperm and Egg Cells) SOMATIC CELLS Each one contains 46 chromosomes (23 pairs).  Chromosomes that carry the same set of genes are called homologous (like a pair of shoes). Diploid (2n) cells Skin cells Eye cells Liver cells

14. SEX CELLS (gametes)-formed during Meiosis Each one contains 23 chromosomes, half of the usual. Each sex cell (sperm and egg) has only one of the chromosomes from each homologous pair. Haploid (n) cells: Egg Sperm SOMATIC VS SEX CELLS

15. MITOISIS REVIEW Somatic cells clone themselves with the process of mitosis. Mitosis replicates a cell with a complete set of 23 chromosomes identical to each other.