1. Cell Reproduction

2. The cell cycle
Interphase
and Mitosis

3. DNA replication Chromatid Sister Chromatids
For most of a cells life chromosome is a single copy of DNA looking like
But during the “s” phase of interphase the chromosome copies itself making sister chromatids joined in the middle by a centromere
Chromatid
Sister Chromatids

4. Chromatid sister chromatids
(because the DNA is copied)

5. Mitosis When a cell go through the phases
Prophase
Metaphase
Anaphase
Telophase
to make two “daughter” cells that are exactly identical to the original “parent” cell

6. Cell parts to know
Chromosomes: the reason they look like an x would be because the DNA has been copied. Each side of the x is a copy of the other.
Spindle fibers: hold chromosomes in an orderly fashion
Centrioles: in animal cells they hold spindle fibers and stretch them to opposite sides of cell
Nuclear membrane breaks down and reforms during the process.

7. Mitosis: cell reproduction to make exact copies of cells
prophase
Interphase
Mitosis: cell reproduction to make exact copies of cells
metaphase
anaphase
telophase
2 daughter cells in Interphase

8. Interphase “normal” cell not dividing just doing its job.
DNA does reproduce. Chromatids form sister chromatids.
Chromosomes
Nuclear membrane

9. Interphase Plant Cell Animal Cell
Photographs from:

10. Prophase Nuclear membrane breaks apart Chromosomes spread out in cell
Spindle fibers form stretching from one side of cell to the other
Nuclear membrane
Chromosome
chromatid
Spindle fiber

11. Prophase Plant Cell Animal Cell Spindle fibers Centrioles
Photographs from:

12. Metaphase Chromosomes line up in center of cell
Held by the spindle fibers

13. Metaphase Plant Cell Animal Cell
Photographs from:

14. Anaphase Chromosomes split
Sister chromatids move to opposite ends of cell
chromatids

15. Anaphase Plant Cell Animal Cell
Photographs from:

16. Telophase 2 nuclear membranes reform around chromatids
Cell membrane splitting into two cells
CYTOKINESIS it the term to describe the division of the cytoplasm and it’s contents which happens when 2 cell membranes are formed.
Nuclear membrane

17. Telophase Plant Cell Animal Cell
Photographs from:

18. Interphase - again 2 new cells
Exact copies with the same chromosomes of original cell
cytoplasm

19. http://www.youtube.com/watch?v=JHRBJgq50dk Crazy mitosis song
Mitosis Animation
Crazy mitosis song

20. Drawing are simplified with only 4 chromosomes.
Human cells have 46 chromosomes
a human skin cell with 46 chromosomes will make more skin cells with 46 chromosomes by doing mitosis

21. Mitosis slides under microscope
Mitosis quiz
Stop motion video or flip book

22. Cancer
Cancerquest: 11 min cancer overview
cancer overview from MD Anderson: 6 min
Cancer detection and treatment:
watch cancer surgery, radioation and chemotherapy,
Website:

23. A different type of cell division!

24. This cell is in the process of dividing
This cell is in the process of dividing. What are two ways this is different from mitosis?
The chromosomes are lined up in pairs not single file as in mitosis– homologous pairs
Pieces of the chromosomes have traded places – crossing over

25. How are the daughter cells produced at the end different from mitosis?
Daughter cells have half the DNA that the parent cell has.
The chromosomes in each of the 4 daughter cells are different as a result of crossing over.
Parent cell
Parent cell

26. Meiosis, What’s the big deal?
Meiosis is the reason that in sexually reproducing organisms
genetic information varies between parent and offspring,
Genetic information varies between offspring from the same parents.

27. Meiosis insures genetic variation which is essential for evolution.
Species genes/traits change from generation to generation.
With a GREAT deal of time this can produce significant changes

28. Meiosis: process to make sex cells
Daughter cells made from Meiosis are NOT identical to the “parent” cell.
Regular body cell 46 chromosomes
Sperm and egg 23 chromosomes
Also crossing over happens where pieces of the original chromosomes exchange places.

29. MEIOSIS: to make sex cells with half the original DNA.
Parent cell
MEIOSIS: to make sex cells with half the original DNA.
4 daughter cells with half of DNA from parent cell

30. Homologous chromosomes
Organisms have pairs of chromosomes with corresponding DNA sequences one from each parent.
homologous chromosomes are the same size, their centromeres are in the same position, they have the same number of genes, arranged in the same order.
n a biological cell, a chromosome pairs with another chromosome during meiosis. This pairing (synapsis) happens between two chromosomes that are homologous, i.e. chromosomes having the same genes at the same loci but possibly different alleles. For example, two chromosomes may have genes encoding eye color, but one may code for brown eyes, the other for blue

31. Meiosis: CROSSING OVER
While paired up during prophase I, sections of DNA are exchanged between homologous chromosomes.
This insures that the chromosomes in sex cells produced are not identical to the parents chromosomes.
This is one reason each offspring produced by a parent is unique from any other.

32. Mitosis vs. Meiosis Parent cell Parent cell
4 daughter cells with half of DNA from parent cell
2 daughter cells with identical DNA to parent cell
2 diploid somatic cells
4 haploid gametes

33. http://highered. mcgraw-hill
animation comparing meiosis and mitosis
questions starting at 15
30 question quiz
3 question quiz
very good animation of meiosis

34. Vocabulary for Bio
Somatic cell: a body cell that has the organisms complete diploid set (2N) of chromosomes.
Diploid = 2N: a cell that contains both sets of homologous chromosomes from the parent.
Gamete: sex cell, sperm or egg cell containing the haploid (1N) set of chromosomes
Haploid = 1N: a cell containing 1 set of genes
Zygote: fertilized egg 2N

35. In Humans 46 chromosomes total
The chromosome you get from your mom and dad contain similar types of information.
For example you get genes for eye color from your mom and genes for eye color from your dad.
The chromosomes can be matched up in pairs called homologous chromosome pairs.

36. Mistakes in meiosis: non-disjunction
Non disjunction: when an error occurs in cell division
* homologous chromosomes do not separate
* Or sister chromosomes do not separate

37. 2 ways nondisjunction can occur

38. Normal nondisjunction in Meiosis I

39. Normal nondisjunction in Meiosis II

40. A genetic disorder is a disease that is caused by an abnormality in an individual's DNA. Abnormalities can range from a small mutation in a single gene to the addition or subtraction of an entire chromosome or set of chromosomes. (

41. Disorders
Most disorders are due to changes within one chromosome not a change to an entire chromosome.
Cystic fibrosis (thick mucus in respiratory system)
Sickle Cell disease (malformed red blood cells that get stuck in capillaries)
Lou Gehrig’s disease/ALS (loss of muscle control)
Due to a change in entire chromosome
Down’s Syndrome /trisomy 21
Edward’s Syndrome Trisomy 18
Patau syndrome Trisomy 13
Klinefelters syndrome XXY
Turner’s Syndrome XO
XYY

42. Trisomy: a third copy of a chromosomes
Trisomy: a third copy of a chromosomes. A few smaller copies can be tolerated in humans for example Chromosome 21 results in down syndrome, However most trisomys are lethal
Monosomies: one missing copy of a chromosome, a female can survive with just one X chromosome, however most monosomies are lethal
Triploid: 2 extra chromosomes this is always lethal in humans but does exist in plants

43. Mitosis: results in two cells with identical chromosomes
Meiosis: results in four cells with different chromosomes