1. Standard
S7L2 a.
Students will explain that cells take in nutrients in order to grow and divide and to make needed materials.

2. Standard
S7L2b.
Students will relate cell structures to basic cell functions.

3. Mitosis & Cell Division

4. There are over 100 trillion cells in the body!
We all started out as a single cell, so how did we get so many????

5. Cells Division or Reproduction
Why is this important?
This is important for growth.
This is important for repair.
This is important for replacement of cells.
Some one-celled organisms reproduce by cell division.

6. How do cells divide? By going through the cell cycle.
The cell’s life cycle is called the cell cycle.
The amount of time for this is different for different types of cells.
There are three parts.

7. First Phase of the Cell Cycle:
Interphase
This is the longest phase of the cell cycle.
This is a period of growth and development of the cell.

9. Interphase

10. Interphase under a microspcope

11. Chromosomes
are structures in the nucleus that contains DNA, the hereditary material of life.
During interphase each chromosome is copied.

12. The duplicated strands
are identical.
are called “sister chromatids.”

13. The center of a chromosome is called the centromere, it joins the two chromatids together to form a chromosome.

14. Stop & Share Interphase & Chromosomes
Interphase is the first stage of the cell cycle.
Interphase is the longest phase of the cell cycle.
Interphase is a period of growth and development.
During interphase the chromosomes duplicate.
The chromosomes are now identical sister chromatids connected by a centromere.

15. The nucleus divides in two ways….
Mitosis
&
Meiosis

16. Mitosis
happens when body or somatic cells make exact copies of each other with the same number of chromosomes.

17. Prophase
Nuclear membrane begins to disassemble (come apart).

19. Picture of Prophase

20. Metaphase

22. Mataphase under the Microscope

23. Anaphase

25. Anaphase

26. Telophase
Nuclear membrane begins to form.

28. Telophase

29. Stop & Share Mitosis
The phases of mitosis are prophase, metaphase, anaphase, and telophase.
Prophase---spindle fibers form
Metaphase---Spindle Fibers Attached, Middle of Cell
Anaphase---Chromatids Separate; Away or Apart
Telophase---Two Nuclei

34. Trick for Remembering Phases
Interphase: Inner Growth
PMAT
Prophase: Poles
Metaphase: Middle of Cell
Anaphase: Apart or Away
Telophase: Two Nuclei
Finally, Cytokinesis

35. How do plant cells divide after mitosis?
In plant cells, a cell plate forms in the middle of the cell.
The cell plate divides the cytoplasm into two parts.
New cell walls form along the cell plate.
New cell membranes form inside the cell walls.

36. Cell Plate

37. Results of Mitosis Each cell in body has same number of chromosomes
Allows growth and replacement of damaged or worn out cells.
Asexual Reproduction:
Binary Fission-mitosis
Budding---growing from side of parent
Regeneration---regrow parts

38. Asexual Reproduction
Regeneration
Budding

39. Bacterial Reproduction
Binary Fission
Reproduction
for Prokaryotic Cells (Bacteria)