Cell Cycle…

3. Cell Cycle… • Does your cell cycle look something like this?

5. Lesson #1.3a - Mitosis

6. Identical Daughter Cells Two identical daughter cells Parent Cell

7. Chromosomes

8. Chromosomes in Dividing Cells • Duplicated chromosomes are called sister chromatids & are held together by the centromere Called Sister Chromatids

9. Karyotype • A picture of the chromosomes from a human cell arranged in pairs by size • First 22 pairs are called autosomes • Last pair are the sex chromosomes • XX female or XY male

10. Boy or Girl? The Y Chromosome Decides Y - Chromosome X - Chromosome

11. Cell Reproduction

12. Types of Cell Reproduction • Asexual reproduction involves a single cell dividing to make 2 new, identical cells, these are called daughter cells • Mitosis & binary fission are examples of asexual reproduction • Sexual reproduction involves two cells (egg & sperm) joining to make a new cell (zygote) that is NOT identical to the original cells • Meiosisis an example

13. Cell Cycle DNA Copied Cells prepare for Division Cells Mature Daughter Cells Cell Divides into Identical cells

14. What’s Happening in Interphase? What the cell looks like Animal Cell What’s occurring

15. Mitosis

16. Mitosis • Division of the nucleus • Only occurs in eukaryotes • Produces somaticcells(ALL but sex cells) • Has four stages • Doesn’t occur in some cells such as brain cells

17. Four Mitotic Stages • Prophase • Metaphase • Anaphase • Telophase

18. Early Prophase • Chromatin in nucleus continues condensing • Mitotic spindleforms from centrioles • Microtubules make up the spindle fibres Cytoplasm Nucleolus Nuclear Membrane Chromosomes

19. Late Prophase • Nuclear membrane & nucleolus are broken down • Chromosomes continue condensing & are clearly visible • Spindle fibers attach to the centromere of each chromosome • Spindlebegin to move to the opposite ends of the cell, stretching out the cell

20. Late Prophase Chromosomes Nucleus & Nucleolus have disintegrated

21. Review of Prophase What the cell looks like Centromeres What’s happening

22. Metaphase • Chromosomes, attached to the centromeresand move to the center of the cell • Chromosomes are now lined up in the middle

23. Metaphase Spindle Fibers Chromosomes lined up in the middle

24. Metaphase Chromosomes

25. Review of Metaphase What the cell looks like

26. Anaphase • Occurs rapidly • Sister chromatids are pulled apart to opposite poles of the cell by spindle fibers • Cell elongates (gets wider)

27. Anaphase Sister Chromatids being separated

28. Anaphase Review What the cell looks like What’s occurring

29. Telophase • Sister chromatids are now at opposite poles • Spindle disassembles • Nuclear envelopeforms around each set of sister chromatids • Nucleolusreappears • CYTOKINESIS begins at the end of this stage • Chromosomes reappear as chromatin

30. Comparison of Anaphase & Telophase

31. “Activity: Mitosis Practice” worksheet (front side only)

34. Cytokinesis • Means division of the cytoplasm • Division of cell into two, identical halves called daughter cells

35. Mitotic Stages

36. Daughter Cells of Mitosis • Have the same number of chromosomes as each otherand as the parent cell from which they were formed • Identical to each other, but smaller than parent cell • Must grow in size to become mature cells (G1 of Interphase)

37. Identical Daughter Cells Chromosome number the same

38. Review of Mitosis

39. Name the Mitotic Stages: start Interphase Prophase Telophase Metaphase Anaphase

40. Eukaryotic Cell Division • Used for growth and repair • Produce two new cells identical to the original cell • Cells are diploid (2n) Chromosomes during Metaphase of mitosis Cytokinesis Anaphase Prophase Metaphase Telophase

41. REMEMBER… Cytokinesis  PMAT + Cytokinesis = Mitotic Phase P M A T rophase naphase etaphase elophase

42. Mitosis Animation Name each stage as you see it occur?

43. Mitosis in Onion Root Tips Do you see any stages of mitosis?

44. Test Yourself over Mitosis

45. Name the Stages of Mitosis: prophase Anaphase Metaphase Interphase Telophase, Prophase cytokinesis Prophase Anaphase

46. Identify the Stages ? Prophase ? ? ? Metaphase Anaphase Prophase ? ? ? Telophase Anaphase Telophase

47. “Activity: Mitosis Practice” worksheet (back side) • CELL CYCLE worksheet and questions • Mitosis Worksheet #1-24 & #1-10 • Mitosis QUIZ practice