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

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5 Lesson #1.3a - Mitosis

6 Identical Daughter Cells Parent Cell Two identical daughter cells

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

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

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 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 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 Sexual reproduction involves two cells (egg & sperm) joining to make a new cell (zygote) that is NOT identical to the original cells Meiosis is an example Meiosis is an example

13 Cell Cycle Daughter Cells DNA Copied Cells Mature Cells prepare for Division 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 Division of the nucleus Only occurs in eukaryotes Only occurs in eukaryotes Produces somatic cells (ALL but sex cells) Produces somatic cells (ALL but sex cells) Has four stages Has four stages Doesn’t occur in some cells such as brain cells Doesn’t occur in some cells such as brain cells

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

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

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

20 Late Prophase Nucleus & Nucleolus have disintegrated Chromosomes

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

22 Metaphase Chromosomes, attached to the centromeres and move to the center of the cell Chromosomes, attached to the centromeres and move to the center of the cell Chromosomes are now lined up in the middle Chromosomes are now lined up in the middle

23 Metaphase Chromosomes lined up in the middle Spindle Fibers

24 Metaphase Chromosomes

25 Review of Metaphase What the cell looks like

26 Anaphase Occurs rapidly Occurs rapidly Sister chromatids are pulled apart to opposite poles of the cell by spindle fibers Sister chromatids are pulled apart to opposite poles of the cell by spindle fibers Cell elongates (gets wider) 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 Sister chromatids are now at opposite poles Spindle disassembles Spindle disassembles Nuclear envelope forms around each set of sister chromatids Nuclear envelope forms around each set of sister chromatids Nucleolus reappears Nucleolus reappears CYTOKINESIS begins at the end of this stage CYTOKINESIS begins at the end of this stage Chromosomes reappear as chromatin Chromosomes reappear as chromatin

30 Comparison of Anaphase & Telophase

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

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34 Cytokinesis Means division of the cytoplasm Means division of the cytoplasm Division of cell into two, identical halves called daughter cells 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 other and as the parent cell from which they were formed Have the same number of chromosomes as each other and as the parent cell from which they were formed Identical to each other, but smaller than parent cell Identical to each other, but smaller than parent cell Must grow in size to become mature cells (G 1 of Interphase) Must grow in size to become mature cells (G 1 of Interphase)

37 Identical Daughter Cells Chromosome number the same

38 Review of Mitosis

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

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

REMEMBER…  PMAT + Cytokinesis = Mitotic Phase PMATPMAT 41

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: Interphase prophase Prophase Metaphase Anaphase Telophase, cytokinesis

46 Identify the Stages Prophase Prophase MetaphaseAnaphase AnaphaseTelophase Telophase ? ? ?? ? ??

47 1.“Activity: Mitosis Practice” worksheet (back side) 2.CELL CYCLE worksheet and questions 3.Mitosis Worksheet #1-24 & # Mitosis QUIZ practice