1. 1/15 Daily Catalyst Pg. 69 Meiosis
1. Predict the effect of a checkpoint existing after S phase that prevents the cell from moving into G2 phase.
2. Describe where in humans we see asexual reproduction.
3. A cell with 10 chromosomes undergoes mitosis. How many daughter cells are created? ___ Each daughter cell has ___ chromosomes.  a. 2, 10 b. 10, 2 c. 1, 10 d. 2, 20

2. 1/15 Daily Catalyst Pg. 69 Meiosis
1. Predict the effect of a checkpoint existing after S phase that prevents the cell from moving into G2 phase.
Cells with abnormal amounts of DNA
2. Describe where in humans we see asexual reproduction.
Mitosis- 2 exact daughter cells
3. A cell with 10 chromosomes undergoes mitosis. How many daughter cells are created? ___ Each daughter cell has ___ chromosomes.  a. 2, 10 b. 10, 2 c. 1, 10 d. 2, 20

3. 1/15 Class Business Pg. 69 Meiosis
Quiz #16 on Friday
Tutoring after school, during 4th period, and during lunch
Schedule tutoring sessions with me
Mitosis packet due on Friday
ALL OF THE PACKET NEEDS TO BE COMPLETED

4. Study Assignment New studying assignment
You are required to study a certain amount of hours per week independently AND with a group/partner per month
Independently= 6 hours per week
Group/partner= 4 hours per month
Sheet is due at the end of each month on the last Friday (Jan. 30th)
Name(s)
Date
Time
Topic(s) Covered
Notes
Signature

5. 1/15 Agenda Pg. 69 Meiosis Daily Catalyst Class Business Meiosis notes
Mitosis worksheet (if time permits)

6. Sexual Reproduction Definition:
Two parents give rise to offspring that have UNIQUE combinations of genes.
Genetic variation

7. Chromosomes in human cells
Homologous Chromosomes:
Two chromosomes with the same length and centromere position
Both carry genes controlling the same inherited characteristic

8. Sex Chromosomes Sex Chromosomes Everything else are autosomes!
Females (XX)
Males (XY)
Everything else are autosomes!

9. **Not all cells will have the same chromosome number**
Chromosome Sets Key Point #1: Number of chromosomes in a set is represented by n.
Diploid
Haploid
Key Point #2: Two chromosome sets 2n
Humans= 46 (2n=46)
Key Point #3: One chromosome set n
Humans= 23 (n=23)
**Not all cells will have the same chromosome number**

10. Why we need N?
When it is time to make sex cells you DON’T want the cells to have 2N (2 sets of chromosomes).
It would mess everything up when an egg and sperm combined, there would be too many chromosomes! 2N N
Sperm and egg cells 4N 2N 2N N

11. Meiosis is very similar to Mitosis
From looking at the stages, we can see that meiosis is very similar to mitosis. In meiosis, the cells grow through duplication and cytokinesis twice! What is the end result of meiosis? To make haploid cells or cells with one set of chromosomes

12. Meiosis goes through ONE MORE round of cell division
MEIOSIS I
MEIOSIS II 1N 1N 1N 1N 1N 1N

13. Meiosis
Key Point #4:
Meiosis goes through 2 cell divisions and ends with 4 genetically DIFFERENT cells.
Why different? Genetic information between chromosomes gets switched.
The chromosomes are made of tightly packed DNA and DNA is our genetic information. The DNA has sections we call genes. The genes are all of our traits- the eye color and hair color. We get all of our DNA from our parents. Our parents copy their DNA through meiosis and when the egg and sperm meet, they have a full set of DNA and you are YOU!
Germ Cell in Interphase
Prophase I
Metaphase I
Anaphase I
Telophase I

14. 2N N N N N In mitosis, the cells have a 2N or two sets of DNA.
In meiosis, 4 cells are created and each have a haploid number of chromosomes or one set.
Use this page to show them that the original 2N cell has twice as much DNA as each of the 4 products of meiosis. N N

15. Meiosis Phase 1 Anaphase Prophase
Chromosomes condense and pair up (homologous)
Anaphase
Chromosomes move towards the poles
Sister chromatids remain attached
In meiosis phase 1, the chromosomes duplicate. The chromosomes pair up with one another forming a tetrad. The tetrad line up in the middle of the cell then during anaphase, the tetrads are pulled apart, so in other words the chromosomes are moved to the opposite ends of the cell. During telophase, the cell pinches off and forms two new cells with diploid number of chromosomes. This is just like mitosis!!!
Metaphase
Homologous chromosomes line up in the middle
Kinetochores are attached to aster
Telophase
Division of cells
Haploid set of chromosomes
Interphase
Same interphase as before

16. Crossing Over Key Point #5: Crossing over
During prophase, DNA molecules from non-sister chromatids break off and “cross over” to other’s DNA
Tetrad

17. Meiosis I At the end of meiosis I: 1  2 cells
Haploid number of chromosomes
46 23

18. Meiosis II Chromosomes lines up in the middle
Because of crossing over, chromatids maybe different
Nuc. Membrane forms, chromosomes uncondense
Cell divides
Spindle forms
Chromosomes are still sister chromatids
Chromatids separate Chromatids move as individuals
Meiosis II

19. Meiosis II At the end of meiosis II: 2 2 cells each = 4 cells
Genetically UNIQUE

20. 46924623

21. Take a step back 1. What is the purpose of mitosis?
1. What is the purpose of meiosis?
What’s the difference between haploid and diploid cells?
Regrowth and repair
To create gametes and sex cells!
Haploid is half set of chromosomes or half N
Diploid is a full set of chromosomes or two set of chromosomes 2N

22. 1/16 Daily Catalyst Pg. 70 Compare M&M1. 2. 3.

23. 1/16 Agenda Pg. 70 Compare M&M Daily Catalyst Class Business
Meiosis review
Concept check
Bozeman Video
Compare and contrast M & M
Quiz #16

25. Whiteboard Review Time!
When I say “show,” hold up your whiteboards
This is a mitosis or meiosis review
Depending what I put on the screen, write
Mitosis or
Meiosis

26. Used for sexual reproduction Meiosis
Sex cells undergo meiosis- sperm and eggs

27. Has 2 cell divisions Meiosis
Meiosis has 2 cells divisions and end with haploid cells or one set of chromosomes.

28. Produces two IDENTICAL daughter cells Mitosis

29. Has 1 cell division Mitosis

30. Creates gametes Meiosis

31. Creates haploid cells Meiosis
Guided Practice
Creates haploid cells Meiosis
meiosis

32. Creates cells with 2N chromosomes Mitosis
Guided Practice
Creates cells with 2N chromosomes Mitosis
mitosis

33. Creates diploid cells Mitosis
Guided Practice
Creates diploid cells Mitosis
mitosis

34. Produces four DIFFERENT daughter cells Meiosis
Guided Practice
Produces four DIFFERENT daughter cells Meiosis
meiosis

35. Genetic information between chromosomes gets switched Meiosis

36. Creates cells with n chromosomes Meiosis

37. Used for growth Mitosis

38. Used to make somatic cells Meiosis
mitosis

39. With a tablemate
Complete concept check 13.3 with your tablemates. These answers need to be discussed and only write down what you need.

40. Compare and Contrast M & M
In your notes on today’s page, 70 compare and contrast mitosis and meiosis. You may use your book for help and pay special attention to chromosomes versus chromatids.

41. Quiz #16
Directions: Silently and independently complete the quiz. Turn your quiz into the basket when you are finished. Pick up the math in science homework.
Time: 15 minutes
Noise: 0 (silent)

42. 9.
10. 8.
11.
12.
13.
14.
15.