1. DO NOW!!!
True or False:
Single–celled organisms can reproduce by cell division.
The only function of cell division is reproduction.
In multicellular organisms, cell division can help repair injured areas.
Cell division produces two cells that are different from each other.
T, F, T, F

2. Mitosis
Unit 2 Lesson 1

3. Why do cells divide? Different reasons: Asexual reproduction
Growth in a multicellular organism
Repair of cells 3

4. Asexual Reproduction
Single celled organism - parent divides to produce two identical offspring.
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6. Growth in multicellular organisms
All living things grow
Body grows - cells in your body produce new cells through cellular division

7. Cell Division for Repair
Cut your hand or break a bone - damaged cells are replaced by new cells (form during cell division)
Some organisms - cell division repairs body parts that have been removed.

8. Cell Division for Repair

9. Genetic Material Form: Double Helix Parts: Adenine Thymine Cytosine
DNA = deoxyribonucleic acid.
Eukaryotic cells - found in the nucleus.
Contains - information that determines the traits living thing inherits from parents and needs to live.
Form: Double Helix
Parts:
Adenine
Thymine
Cytosine
Guanine 9

10. Chromatin Most of Cells life - DNA exists as chromatin.
When the DNA Duplicates, you have 46 duplicated chromosome. They are considered one duplicated chromosome. When they separate during anaphase then one duplicated chromosome becomes two chromosomes. 10

11. Before Mitosis
Before cell division – DNA (chromatin) - duplicates. =

12. Chromosome (Condensed DNA)
As Mitosis begins - duplicated chromatin (DNA)  Sister chromatids  sister chromatids condense = Duplicated Chromosome

13. Chromosomes under the Microscope

14. Different levels of DNA condensation: (1) Single DNA strand
Different levels of DNA condensation: (1) Single DNA strand. (2) Chromatin strand (3) Chromatin during interphase with centromere (4) Chromatin Duplicated  Sister Chromatids (5) Sister Chromatids Condense = Duplicated Chromosome

15. Chromosome DNA Chromatin
Chromatin  Chromatin Duplicates = Sister Chromatids  Sister Chromatids Condense = Duplicated Chromosome
Chromosome
DNA
Chromatin 15

16. HW
Turn to page 92 and 93 and Complete Questions 5 to 7

17. DO NOW!!! Highlight Definition for: Interphase Mitosis Cytokinesis
On pages 94 and 95!!!
Then do question #10.

18. Stages of the cell cycle
Life cycle of a eukaryotic cell - cell cycle - divided into three stages:
Interphase
Mitosis
Cytokinesis. 18

19. Interphase Interphase - stage of cell cycle when cell is not dividing.
Cell spends 90% of its life here
Cell engages in normal life activities
transporting materials
getting rid of waste 19

20. Interphase Before Cell Division
Cell grows - 2x its size -producing more organelles and cytoplasm.
DNA is duplicated
Changes prepare cell for division.

21. Mitosis – Cell Division
Eukaryotic cells - part of cell cycle where nucleus divides.
4 phases:
Prophase
Metaphase
Anaphase
Telophase
Prokaryotes – No nucleus = No Mitosis 21

22. Mitosis (Cell Division)
Creates:
2 identical nucleuses
2 identical sets of chromosomes in in each nucleus
During – Duplicated chromatin  sister chromatids condense  Duplicated chromosomes

23. Cytokinesis Cytokinesis - division cytoplasm.
Starts - last step of mitosis (telophase)
Forms – 2 identical cells 23

24. Cytokinesis in Animal Cells
Animal cells - cell membrane pinches inward between 2 nucleuses.
Pinches all the way - forming two complete cells

25. Cytokinesis in Plant Cells
Cell wall – No Pinch – Cell Plate forms between 2 nucleuses and separates cell into 2 identical cells

28. HW
Read page 96 and 97 then fill out the table on page 97, #13.

29. DO NOW!!!
gy/mitosis.html Mitosis video : Lets watch what is really happening!

30. The 4 Phases of Mitosis Prophase Metaphase Anaphase Telophase
By the end of the four phases, the cell will have two identical nuclei. 30

31. Prophase Spindle fibers attach to the centromeres of every chromosome.
Duplicated Chromatin = Sister Chromatids  Sister Chromatids Condense = Duplicated Chromosomes
Each Chromosome = two chromatids held together by a centromere.
Nuclear membrane – breaks
down
Spindle fibers attach to the centromeres of every chromosome. 31

32. Metaphase Chromosomes line up in the middle of the cell.
Centromeres of chromosomes - same distance from each side of the cell. 32

33. Anaphase
Duplicated Chromatids of each chromosome are pulled apart to opposite sides of the cell.
Note on it pinching in during this picture and ask students about it. 33

34. Telophase + Cytokinesis
New nuclear membrane forms around each group of chromosomes
Chromosomes - become less condensed.
Cytokinesis begins 34

35. Cytokinesis After mitosis - cytokinesis forms two new identical cells
Cycle starts again for each cell 35

38. Activity + HW
Listen to the Mitosis Song to Learn more about this topic:
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In Class Complete the Visual summary on page 98 and the Unit 2 Lesson 1 Review on Page 99

39. Class Activity Create a Picture Poster Showing: .
What happens to genetic material (DNA) in a cell before cell division (Mitosis)
Use these Labels – Chromatin  chromatin duplicates  sister chromatids  sister chromatids condense = Duplicated chromosome
What happens to that genetic material (DNA) and the cell once cell division occurs (Mitosis)
Use Mitosis labels – Interphase, Prophase, Anaphase, Telophase, & Cytokinesis – Explain what happens in each stage