1. DNA and Mitosis review/Meiosis
How do your cells divide?
This PowerPoint has many animated slide progressions. You may only want to print the following slides: 1-11, 14-15, 22-47

2. A few words before we start…..
Haploid: half of a full
set (only 1 set of DNA)
Diploid: full set (1 set from
each parent (2 sets)
Haploid – number of chromosomes in sex cells represented by n indicating one chromosome
Diploid - number of chromosomes in somatic cells represented by 2n indicating a set or double number of chromosomes

3. A Cell’s Life Interphase
Have students notice that the majority of a cell’s life is spent in interphase and during that time, the cell is performing all it’s cellular processes needed to survive. Indicate that M is Mitosis, the small amount of time the cell spends dividing.
Picture taken from

4. Why Do Cells Divide? Growth Damaged cells Sex cells
Answers are animated so you can ask students the question before you reveal the answers
Maintain workable surface area to volume - too big-can’t work!!
Replace damaged cells
Produce sex cells
Sex cells

5. Cell Reproduction
is either sexual or asexual

6. Asexual Reproduction (one parent)
Binary Fission-
Budding
Vegetative Propagation
Regeneration
Advantages?
Binary Fission - split in two (bacteria)
Budding- (Yeast)
Vegetative Propagation - (Plants)
Regeneration -
Disadvantages?

7. Asexual reproduction Advantages: Disadvantages: Doesn’t require a mate
Takes less time
Disadvantages:
All offspring are the same (genetically)

8. Sexual Reproduction 2 “parents” or 2 sets of DNA
Examples: humans, plants, dogs

9. Sexual reproduction Advantages Disadvantages? DIVERSITY!!!!!!!!!!
Offspring are genetically different from parents.
Disadvantages?
Need a mate
Takes longer

10. Mitosis Animation
This animation is a review of mitosis. Have students review what is happening to the chromosomes.
Animation from

11. Mitosis Review 1. Is the beginning parent cell diploid or haploid
(2n or n)?
2. Are the daughter cells diploid or haploid (2n or n)?
Questions are animated so you can ask each question and get an answer before going to the next question.

12. More Mitosis Review 3. How many daughter cells are produced?
4. Are the resulting daughter cells different from the parent cell?

13. More Mitosis Review
5. Are the resulting daughter cells different from each other?
6. How many chromosomes are in a human parent cell?
Questions are animated so you can ask each question and get an answer before going to the next question.
7. How many chromosomes are in a human daughter cell?

14. More Mitosis Review 8.What types of cells are produced by mitosis?
9. Why (when) does a cell go through mitosis?

15. Meiosis
Sexual Reproduction (two parents)

16. Why Meiosis? Meiosis - The production of gametes
Meiosis is the production of sex cells (gametes). During meiosis, the number of chromosomes in the daughter cells are reduced from the number of chromosomes in the parent cell (this is extremely important).

17. Interphase Cell growth
DNA replication  sister chromatids held together by centromere

18. Prophase I The chromosomes coil up and a spindle forms.
Homologous chromosomes line up with each other gene by gene along their length, to form a four-part structure called a tetrad.

19. Prophase I – crossing over
Crossing over occurs between homologous chromosomes  new genetic combinations that are different from the parent.

20. Metaphase I
The spindle fibers pull the tetrads into the middle, or equator of the cell.
There is no rule to who is on left or right side  independent assortment.

21. Anaphase I
Homologous chromosomes separate and move to opposite ends of the cell.

22. Telophase I
The spindle is broken down, the chromosomes uncoil slightly, and the cytoplasm divides to yield two new cells.
Each cell has half the DNA as the original cell because it has only one chromosome from each homologous pair.  Diploid

23. Remember mitosis?
Meiosis II looks just like mitosis except there is no DNA replication during interphase

24. Prophase II
A spindle forms in each of the two new cells and the spindle fibers attach to the chromosomes.

25. Metaphase II.
Sister chromatids, are pulled to the center of the cell and line up randomly at the equator.

26. Anaphase II
The sister chromatids separate and move to opposite poles.

27. Telophase II
Finally nuclei reform, the spindles breakdown, and the cytoplasm divides.
Four haploid cells have been formed from one diploid cell
All are genetically different from each other and from the parent cell.

29. How does Meiosis Occur? Animation of meiosis to use as a review
Meiosis Animation from

30. Why meiosis is important
Forms gametes for sexual reproduction
Crossing over and independent assortment  different genetic combinations.  diversity!!!

31. Meiosis Review
Is the beginning parent cell diploid or haploid (2n or n)?
2. Are the resulting daughter cells diploid or haploid (2n or n)?
Questions are animated so you can ask each question and get an answer before going to the next question.

32. More Meiosis Review 3. How many daughter cells are produced?
Are the resulting daughter cells different
from the
parent cell?

33. More Meiosis Review
5. Are the resulting daughter cells different from each other?
6. How many chromosomes are in a human parent cell?
Questions are animated so you can ask each question and get an answer before going to the next question.
7. How many chromosomes are in a human daughter cell?

34. More Meiosis Review
8. What types of cells are produced by meiosis?

35. Fertilization Mom Dad 23 46 New Individual 23
Formation of a new individual through the union of parent cells
The number of chromosomes are animated so you can ask students the answers before it comes up
New Individual 46

36. This is how new organisms are made!!

37. Mitosis and Development
Sexual reproduction
Haploid gametes
(n=23)
Sperm Cell
Meiosis
Meiosis
Egg Cell
Fertilization
Diploid zygote
(2n=46)
Mitosis and Development
Multicellular
diploid adults
(2n=46)

38. Let’s review
Mitosis & Meiosis

39. Visual review of the differences between mitosis and meiosis

40. Mitosis vs. Meiosis √ √ √ √ √ √ Event Mitosis Meiosis Produces 4 cells
Mitosis vs. Meiosis
Event
Mitosis
Meiosis
Produces 4 cells
Produces 2 cells
New cells identical
New cells different
New cells have the same number of chromosomes as parent
New cells have fewer chromosomes than parent √ √ √ √
The answers are animated so you can have students answer the question before you reveal the answer. √ √

41. Mitosis vs. Meiosis √ √ √ √ √ Event Mitosis Meiosis
Mitosis vs. Meiosis
Event
Mitosis
Meiosis
Beginning cells diploid (2n)
Beginning cells haploid (n)
Ending cells diploid (2n)
Ending cells haploid (n)
Produces egg and sperm
Produces body cells √ √ √
The answers are animated so you can have students answer the question before you reveal the answer. √ √