1. Cell Reproduction and Heredity
USV: Mitosis and Meiosis
Ask them to get down the 5 phases and what happens in each.

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

3. Why do animals shed their skin?

4. Three reasons why cells reproduce by asexual reproduction:
Growth
2. Repair
3. Replacement

5. Animated Mitosis Cycle
Interphase
Prophase
Metaphase
Anaphase
Telophase & Cytokinesis

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

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

8. Plant vs. Animal ANIMAL Cell membrane pinches apart Has centrioles
Rigid cell walls do not pinch apart
Cell plate forms between 2 new nuclei
No centrioles

9. Asexual Reproduction Organisms produced from one parent like mitosis
FISSION = division of organism into parts (bacteria)
Body cells do this

10. Asexual Reproduction
REGENERATION = whole organism may develop from piece of organism or when organism is injured (sponges, planaria, sea stars)
BUDDING = organism grows from body of parent (hydra)

11. Meiosis 46
Sexual Reproduction = new organism produced when sex cells from 2 parents combine
Sperm and Egg cell (104)
Meiosis = process of nuclear division that produces sex cells in the reproductive organs 46 46 23 23 23 23 46 46 46 23 23 23 23

12. Meiosis Human cells have 23 pairs of chromosomes 46 total
Sex cells have 23 chromosomes
Why??
Diploid = cell that has 2 of every kind of chromosome
Haploid = Sex cell with 1 chromosome from each pair

13. Meiosis Fertilization = joining of egg and sperm23 46 23
Fertilization = joining of egg and sperm
Zygote = cell that forms during fertilization
The zygote will then undergo mitosis to develop
Picture handout

14. Meiosis l & ll Please look at your handout What do you see happening?
Begins with 1 cell
Meiosis l forms 2 cells
Meiosis ll results in 4 cells

15. Differences Mitosis Meiosis 2 nuclear divisions 1 nuclear division
Chromosomes line up in pairs
½ number of chromosomes
4 cells
Crossing over during Prophase I
Mitosis
1 nuclear division
Chromosomes line up singly
Same # of chromosomes
2 cells
No crossing over