1. Cell Division By: Amber Tharpe

2. Activation  Humans make 2 trillion new cells per day

3. Cell Cycle  2 main parts Interphase- Cell is normal Mitosis- Cell is dividing  Cytokinesis- occurs at the end of mitosis

4. Mitosis  Divides DNA into 2 nuclei  Makes 2 daughter cells with a diploid number  Used for growth and repair  Also used in some asexual reproduction

5. 4 stages (P-M-A-T) 1. Prophase 2. Metaphase 3. Anaphase 4. Telophase

6. Stages of Mitosis (P-M-A-T) Interphase Early Prophase Metaphase Early Anaphase Prophase AnaphaseTelophase http://micro.magnet.fsu.edu/micro/gallery/mitosis/mitosis.html

7. Prophase  DNA condenses  Nuclear envelope dissolves  Spindle fibers start to form

8. Prophase (in animal cell and onion cell)

9. Metaphase  Chromosomes align in the middle of the cell (equator)  Spindle fibers attach to the chromosomes to move them

10. Metaphase

11. Anaphase  Chromosomes separate to opposite poles  Spindle fibers split chromosomes in half

12. Anaphase

13. Telophase  2 nuclear envelopes form around the separated DNA  Spindle fibers dissolve  In animal cells Cell membrane pinches in  In plant cells Cell plate forms which later becomes 2 cell walls

14. Telophase

15. Cytokinesis  Cytoplasm and organelles divide  2 cells form

16.  http://www.classzone.com/cz/books /bio_07/get_chapter_group.htm?cin =2&rg=animated_biology&at=anim ated_biology&var=animated_biolog y

17. Animation of Stages of Mitosis http://biology.about.com/library/blmitosisanim.htm

18. Asexual Reproduction  1 parent  Offspring is identical to parent  Less genetic diversity

19. Binary Fission  Asexual reproduction for bacteria  DNA is copied in 1 cell  The cell divides into 2 cells with the same DNA

20. Binary Fission

21.  http://www.classzone.com/cz/books /bio_07/get_chapter_group.htm?cin =2&rg=animated_biology&at=anim ated_biology&var=animated_biolog y

22. Chromosome  Long thread of DNA containing many genes  X- shaped

23. Somatic cells  Body cells  All cells not involved in reproduction  Diploid cells (2N) Contains 2 copies of each chromosome In humans 46 chromosomes  Made by mitosis

24. Gametes  Sex cells  Egg (female) or sperm (male)  Haploid cells (1N) Contains 1 copy of each chromosome In humans 23 chromosomes  Made by meiosis  Used in sexual reproduction

25.  Sex Chromosomes Chromosome pair 23 for gender Either X or Y XX is female XY is male

26. Sexual Reproduction  Offspring are a mixture of both parents  Occurs by meiosis then fertilization  Meiosis Formation of gametes Makes haploid cells from diploid cells  Fertilization The actual fusion of the 2 gametes First cell is called a zygote

27. Asexual Reproduction Sexual Reproduction advantages1 parent, requires less energy, fast Increases genetic diversity, increasing the ability to adapt disadvantages Decreases genetic diversity, Less likely to adapt 2 parents, requires more energy, slow

28. Meiosis  Process of making gametes for sexual reproduction  Events that occur during meiosis allows for greater genetic diversity

29. Meiosis  Meiosis I Makes 2 unique diploid cells Prophase I – Telophase I  Interphase without duplicating DNA  Meiosis II Makes 4 unique haploid cells Prophase II – Telophase II

30. Crossing Over  Occurs in Prophase I Homologous chromosomes line up and sections of the chromosomes overlap and become incorporated into the other Allows for genetic diversity

31. Independent Assortment  Occurs in Metaphase I  Independent Assortment Allows for genetic variation When homologous chromosomes line up in the middle, some chromosomes from the mother and father line up on either side

32. Telophase II  Produces 4 haploid cells with unique combinations of chromosomes  Females produce 1 ovum (egg) and 3 polar bodies  Males produce 4 sperm cells