1. How do little elephants grow up to be BIG elephants?

3. MITOSIS
The process in which the nucleus divides to form two identical nuclei
All human body cells, except sex cells, divide through mitosis

4. Mitosis Cycle Interphase (before mitosis begins) Prophase Metaphase
Interphase (before mitosis begins)
Prophase
Metaphase
Anaphase
Telophase & Cytokinesis (after mitosis)

5. Interphase is a long period of growth and development
Chromosomes are copied (# doubles)
CELL MEMBRANE
Nucleus
Cytoplasm

6. Plant Cell
Animal Cell

7. Mitosis begins (cell begins to divide)
A duplicated chromosome has two identical tightly coiled DNA strands, called chromatids, that are held together at a region called the centromere.
Centrioles (or poles) appear and begin to move to opposite end of the cell.
Spindle fibers form between the poles
Nuclear membrane disappears. .
Centrioles
Sister chromatids
Spindle fibers

8. Plant Cell
Animal Cell
Spindle fibers
Centrioles

9. Chromatids (or pairs of chromosomes) attach to the spindle fibers and line up in the middle of the cell.
Centrioles
Spindle fibers

10. Plant Cell
Animal Cell

11. Spindle fibers shorten and Chromatids(or pairs of chromosomes) separate and begin to move to opposite ends of the cell.
The chromatids are now separated and are called chromosomes.
Centrioles
Spindle fibers

12. Plant Cell
Animal Cell

13. Spindle fibers disappear. Chromosomes uncoil. Mitosis ends.
Two new nuclei form.
Spindle fibers disappear.
Chromosomes uncoil.
Mitosis ends.
Nuclei
Nuclei
Chromosome

14. Plant Cell
Animal Cell

15. Cell membrane moves inward to create two daughter cells – each with its own nucleus with identical chromosomes.

16. Animal Mitosis -- Review
Interphase                                                             
Prophase                                                             
Metaphase                                                             
Anaphase                                                             
Telophase                                                             

17. Plant Mitosis -- Review
Interphase                                                             
Prophase                                                             
Metaphase                                                             
Anaphase                                                             
Telophase                                                             

18. Cell Cycle

19. Mitosis Animation

20. MEIOSIS Cell division for sex cells (sperm and egg)
TWO divisions of the nucleus
Meiosis I
Two cells form
Meiosis II
Both of the cells from Meiosis I form two cells for a total of four sex cells.
Each sex cell has one-half the number of chromosomes in its nucleus that was in the original nucleus. From a human cell with 46 paired chromosomes, meiosis produces four sex cells each with 23 unpaired chromosomes.

21. Meiosis I
Meiosis II

22. http://highered. mcgraw-hill