1. Cell Reproduction:
The Cell Cycle

2. Dust off that memory… Discuss with your partner mitosis.
1. What was the end result?
2. How many stages were there?
3. What order did they happen in?
4. How many pairs of chromosomes to humans have anyway?
5. Why are they arranged in pairs?

3. Recall Mitosis Results in 2 daughter cells Process has 4 stages
prophase, metaphase, anaphase, telophase and cytokinesis
Humans have 23 PAIRS of chromosomes

4. Remember: IPMAT!

5. Can that be right!?!?!
If the end result of mitosis is two identical daughter cells, then when a male gamete(sperm) and a female gamete(egg) come together during fertilization there must be 92 chromosomes!!!
Mom (23 pairs) + Dad (23 pairs) = Baby with 46 pairs!!!!

6. Meiosis!
Meiosis is a second round of cell division that separates sister chromatids in sex cells allowing the offspring to have the same number of chromosome pairs as their parents!
Males: Sperm
23 chromosomes
Females: Egg
23 chromosomes

7. Half from Dad, half from Mom combine in offspring for 23 PAIRS!

8. What is Meiosis?
Cell division with two divisions of the nucleus, resulting in 4 unique haploid gametes.
Where does it occur?
In the cells which produce gametes: sex cells
Mom (23 pairs) + Dad (23 pairs) = Baby with 23 pairs!!!!

9. Talking like a scientist…scientific vocabulary.
Haploid: cell containing one of each kind of chromosome (n)
Diploid: cell with 2 of each kind of chromosome (2n)

10. Scientific Vocabulary continued…
In a diploid cell chromosomes of each pair are called homologous chromosomes
Contain the same traits, but different forms of a gene called alleles for example brown hair vs. blonde hair

11. Turn notes over! No peeking!
Quick!
How many individual chromosomes do humans have? 46
A chimpanzee has a diploid number of 48, what is its haploid number? 24

12. Foundational Facts Recall from mitosis:
IPMAT =interphase, prophase, metaphase,anaphase, telophase
Chromosome: tightly wound DNA
Sister Chromatids: two halves of the doubled chromosome structure

13. Meiosis Starts with two homologous chromosomes
Two stages of nuclear division:
Meiosis I = P.M.A.T.
Meiosis II = P.M.A.T.
Creates 4 unique haploid cells

14. Phase review
Prophase:

15. Phase Review
Metaphase

16. Phase Review
Anaphase-
Telophase-

17. The first five stages look identical to mitosis…however it is the further separation of