1. bellringer
Write the questions and answers in your composition books. (YOU CANNOT USE YOUR NOTES)
What is mitosis in your own words?
What is the acronym used when describing mitosis?
How many cells are made at the end of mitosis? Are they identical or different?

2. Mitosis & Meiosis
Mitosis animation:

3. Mitosis:
If a cell wants to make a duplicate of itself, it first must copy its DNA (part of a chromosome).
The copies then must be separated & sorted into two sides of the cell.
The cell then splits in two. Part of each parent is carried to the two new cells.
Results in cells such as internal organs, skin, bones, blood, etc.

4. This may you remember these terms:
MITosis takes the cell and Makes It Two (diploid)
Meiosis has to do with sex
From the cell’s point of view:
mITosis results in Identical Twins
mEioSis results in Egg and Sperm (haploid)
Clyde Freeman Herreid – Dept. of Biological Sciences: Buffalo State Univ. of New York

5. Bell ringer: When a cell is diploid how many chromosomes does it have?
When a cell is haploid, how many chromosomes does it have?
Provide an example of a diploid cell and a haploid cell?
What is the difference between a gene mutation and a chromosomal mutation?

6. Each resulting cell still has chromosomes from mom & dad
Mitosis: Meiosis:
Explain the randomness in meiosis
End of first class
Each resulting cell still has chromosomes from mom & dad

7. Interphase occurs just before Mitosis begins:
DNA is replicated along with organelles and other cellular components and the cell prepares for division.

8. Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Mitosis Interphase
Animal cell
Plant cell
Photographs from:

9. 1st step in Mitosis: Prophase (preparation phase)
The DNA recoils, and the chromosomes condense; the nuclear membrane disappears, and the mitotic spindles begin to form.

10. Bell Ringer: Write the questions
What is occurring inside of the cells during prophase of mitosis?
What are the possible genotype for an individual with blood type B?
What are autosomes?
What type of cell is 2n?

11. Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Mitosis Prophase
Animal cell
Plant cell
Photographs from:

12. 2nd step in Mitosis: metaphase (organizational phase)
The chromosomes line up the middle of the cell with the help of spindle fibers attached to the centromere of each replicated chromosome.

13. Bell ringer (write the question)
At which phase of mitosis do you expect to see the nucleus forming again?
When do you first see the mitotic spindles?
Explain what is occurring in anaphase?

14. Meiosis:
As in mitosis, if a cell wants to make a duplicate of itself, it first must copy its DNA (part of a chromosome).
Results in reproductive cells (sperm, eggs, etc).
Part of each parent is carried to the four new cells.
Meiosis has evolved to solve a problem.
The problem is this: some organisms have sex with other organisms – that is, they combine their genes together (creating genetic diversity).
Why would this be a problem?

15. Mitosis Metaphase Animal cell Plant cell
Photographs from:

16. 3rd step in Mitosis: Anaphase (separation phase)
The chromosomes split in the middle and the sister chromatids are pulled by the spindle fibers to opposite poles of the cell.

17. Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Mitosis Anaphase
Plant cell
Animal cell
Photographs from:

18. 4th step in Mitosis: Telophase
The chromosomes, along with the cytoplasm and its organelles and membranes are divided into 2 portions. This diagram shows the end of telophase.

19. Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm
Mitosis Telophase
Animal cell
Plant cell
Photographs from:

20. After Mitosis: Cytokinesis
Beginning of cytokinesis in a plant:
The actual splitting of
the daughter cells into
two separate cells is
called cytokinesis and
occurs differently in
both plant and animal
Cells.
Beginning of cytokinesis in an animal:

21. Mitosis Booklet You are to make a mitosis booklet
Must include the following:
Title page (with name, date, period, and picture) (2pt)
Table of contents (1 pt)
Define mitosis and state why it is important for body cells to undergo mitosis (2pts)
Different stages of mitosis with a sub heading. Each phase needs to have its own separate page (PMAT, cytokinesis and interphase) (6pts)
Needs to give an explanation of what is happening at each stage of mitosis (PMAT, cytokinesis, and Interphase) (6pts)
Picture of each stage in an animal cell and plant cell (total 12 pics) (12 pts) can be hand drawn or printed
Page explaining what cancer is and why it happens. (2pts)
Needs to be creative (2pts)
Total pts: 33 pts (ALL THE INFORMATION NEEDS TO BE TYPED AND PASTED IN THE BOOKLET)

22. Meiosis Meiosis animation:
Beginning of third class

23. Vocabulary Diploid Haploid Germ cell Somatic cell Interphase Prophase
Metaphase
Anaphase
Telophase
Cytokinesis

24. Bell ringer What is fertilization?
What is the process called for the formation of both reproductive cells?
What is the general name for the location where meiosis occurs?
Meiosis produces how many cells? Are they identical? Haploid or diploid?

25. Meiosis Sex cells divide to produce GAMETES (sperm or egg).
Gametes have HALF the # of chromosomes.
Occurs only in GONADS (testes or ovaries).
Male: SPERMATOGENESIS -sperm
Female: OOGENESIS - egg or ova

26. Fertilization The fusion of a sperm and egg to form a zygote.
A zygote is a FERTILIZED EGG
n=23
egg
sperm
n=23
2n=46
zygote

28. Meiosis Interphase
Meiosis is preceded by interphase. The chromosomes have not yet condensed.

29. MEIOSIS I
Meiosis I
Homologs separate

30. Meiosis Interphase
The chromosomes have replicated, and the chromatin begins to condense.

31. Meiosis Prophase I
The chromosomes are completely condensed. In meiosis (unlike mitosis), the homologous chromosomes pair with one another
Crossing over occurs

32. Metaphase I Shortest phase Tetrads align on the equator.
Independent assortment occurs – chromosomes separate randomly causing GENETIC RECOMBINATION

33. Homologs line up at equator or metaphase plate
Metaphase I
Homologs line up at equator or metaphase plate OR

34. Meiosis Anaphase I The chromosomes move to opposite ends of the cell.

35. Meiosis Telophase I & Cytokinesis
The cell begins to divide into two daughter cells. It is important to understand that each daughter cell can get any combination of maternal and paternal chromosomes.

36. Sister Chromatids Separate
MEIOSIS II
Sister Chromatids Separate
Meiosis II

37. Meiosis Prophase II The cell has divided into two daughter cells.

38. Meiosis Metaphase II
As in Meiosis I, the chromosomes line up on the spindle fibers.

39. Meiosis Anaphase II
The two cells each begin to divide. As in Meiosis I, the chromosomes move to opposite ends of each cell.

40. Telophase II & Cytokinesis
With the formation of four cells, meiosis is over. Each of these prospective germ cells carries half the number of chromosomes of somatic cells.

41. Nondisjunction
Nondisjunction is the failure of chromosome pairs to separate properly during meiosis 1 or meiosis 2

42. Bell ringer: (write the question)
How are meiosis 1 and meiosis 2 different?
What is nondisjunction?
Which phase of meiosis is consider the longest? (hint: were does crossing over occur)
Which phase of meiosis is considered the shortest?

43. Question:
A cell containing 20 chromosomes (diploid) at the beginning of meiosis would, at its completion, produce cells containing how many chromosomes?

44. 10 chromosomes (haploid)
Answer:
10 chromosomes (haploid)

45. Question:
A cell containing 40 chromatids at the beginning of meiosis would, at its completion, produce cells containing how many chromosomes?

46. Answer:
10 chromosomes

47. Non-disjunctions usually occur in one of two fashions.
The first is called Monosomy, the second is called Trisomy. If an organism has Trisomy 18 it has three chromosomes in the 18th set, Trisomy 21…. Three chromosomes in the 21st set. If an organism has Monosomy 23 it has only one chromosome in the 23rd set.

48. Common Non-disjunction Disorders
Down’s Syndrome – Trisomy 21
Turner’s Syndrome – Monosomy 23 (X)
Kleinfelter’s Syndrome – Trisomy 23 (XXY)
Edward’s Syndrome – Trisomy 18

49. Amniocentesis
An Amniocentesis is a prrocedure a pregnant woman can have in order to detect some genetics disorders…..such as non-disjunction.

50. Amniocentesis
Amniotic fluid withdrawn

51. Karyotype (picture of an individual’s chromosomes)
One of the ways to analyze the amniocentesis is to make a Karyotype
What genetic disorder does this karyotype show?
Trisomy 21….Down’s Syndrome

52. Bell ringer: write the question
What is amniocentesis?
What can non-disjunction produce?
What are the stages of mitosis?
In what stage of the cell cycle does the DNA get duplicated?