Why Do Cells Divide?► To    repair injured tissues► For   growth (to add bulk)► To    replace dead cells► Depending on the...
Types of Cell ReproductionAsexual  Reproduction              Sexual Reproduction                            ► Involves two...
Cell Division Types
Words to KnowChromatin► Long stretched out  rods of DNA► Everyday life of  cell, DNA able to be  read by cell to do  workC...
Words to KnowSister Chromatids► Chromosomes  replicate before  mitosis► The two identical  copies are attached  by a centr...
Words to Know      Homologous ChromosomesYou have two copies of every chromosome  (one from mom, one from dad) in each of ...
Homologous Chromosomes
More Background/Words to Know►   Each of your body cells    ►   Each of your sex cells    contains 46 chromosomes,       c...
The Cell Cycle► The   life cycle of the  cell is known as the  cell cycle► Itis divided into  Interphase and the  Mitotic ...
The Cell CycleInterphase is divided into Mitotic phase has 4 phases:  3 sections:              Prophase                   ...
Interphase► Early Interphase         ► Late   Interphase► The cell performs its    ► At this point, both the  normal funct...
Interphase
Prophase►   Nuclear membrane breaks    down exposing    chromosomes►   Nucleolus disappears►   Centrioles migrate to    op...
Metaphase► The spindle fibers pull the chromosomes by their centromeres until they line up down the middle AKA equator of ...
Anaphase► The   centromeres of  the sister chromatids  split and the  individual chromatids  separate, being  pulled by th...
Telophase► The  spindle breaks  down► Nuclear membrane  returns► Nucleolus reappears► Centriole returns to its  normal spo...
Cytokinesis► This  is the process  by which the rest of  the cell begins to  divide► The cell membane  begins to pinch in ...
Cytokinesis► Begins in late  anaphase► Is completed as  telophase ends     Mitosis+    Cytokinesis     Cell Division
Mitosis Summary & Animation  http://www.youtube.com/watch?v=s4PaOz7eWS8
Mitosis Review
Which Phase Is It?
Meiosis pp. 196-197► Has  two parts: Meiosis ► Meiosis II is simply a  I and Meiosis II          mitotic division► Meiosis...
Crossing Over► Occurs  in Prophase I► Homologous pairs form  a tetrad (4)► They exchange genes  AKA genetic  recombination...
Meiosis Summary & Animation   http://www.youtube.com/watch?v=D1_-mQS_FZ0
Mitosis vs. Meiosis                     Mitosis           Meiosis   Location       Somatic Cells   Gonads (ovaries or     ...
Mitosis vs. Meiosis
Egg Cell vs. Sperm Cell Production                       (#, size, motility)3 Polar bodies                 1 Ovum (egg)   ...
Sexual Reproduction              +                 =Haploid (n)       Haploid (n)       Diploid (2n) Gamete            Gam...
Chromosomal Mutations                          ► Otherchromosomal► Down   Syndrome is       mutations include:  caused by ...
Diagnosis► An  amniocentesis  takes cells from the  developing fetus (dead  skin cells floating in  the amniotic fluid)► A...
Karyotypes
Normal Cells vs. Cancer Cells      Normal Cells                      Cancer CellsGenetic factors (tumor           Other ge...
Normal Cells vs. Cancer Cells        Normal Cells                    Cancer CellsNormal cells show density      Cancer cel...
Normal Cells vs. Cancer CellsNormal Cells                          Cancer CellsNormal cell growth/division is also   Cance...
Traditional Cancer Treatment OptionsSurgery                 Localized removal of                        cancerous cells (t...
Other Cancer Treatment OptionsImmunotherapy             Enhances body’s naturalEffective only for some   immune response t...
Helpful Resource:► http://www.cancerquest.org/cell-division- mitosis.html   This website has great animations and    expl...
Cell Division
Upcoming SlideShare
Loading in …5
×

Cell Division

737 views
487 views

Published on

Published in: Education
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
737
On SlideShare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
13
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Cell Division

  1. 1. Why Do Cells Divide?► To repair injured tissues► For growth (to add bulk)► To replace dead cells► Depending on their function, some cells divide every few hours/days/weeks, others not at all
  2. 2. Types of Cell ReproductionAsexual Reproduction Sexual Reproduction ► Involves two parents► Involves one parent cell that divides into (an egg cell and a two sperm cell) ► Daughter cells are► Daughter cells are identical to the parent genetically different cell (clones) than either parent ► Meiosis produces► Mitosis produces clones egg and sperm cells ► Some organisms can► AKA binary fission in some single celled reproduce either organisms (bacteria) sexually or asexually
  3. 3. Cell Division Types
  4. 4. Words to KnowChromatin► Long stretched out rods of DNA► Everyday life of cell, DNA able to be read by cell to do workChromosomes► Condensed DNA► Occurs in preparation for mitosis
  5. 5. Words to KnowSister Chromatids► Chromosomes replicate before mitosis► The two identical copies are attached by a centromere
  6. 6. Words to Know Homologous ChromosomesYou have two copies of every chromosome (one from mom, one from dad) in each of your cells► They are similar (same genes in the same location on specific numbered chromosomes) but not necessarily identical (hair color: brown gene from mom, black gene from dad)
  7. 7. Homologous Chromosomes
  8. 8. More Background/Words to Know► Each of your body cells ► Each of your sex cells contains 46 chromosomes, contain 23 chromosomes, 23 from your mom and 23 only one of each from your dad AKA chromosome AKA haploid diploid (2n) (n)► Body cells are called ► Sex cells are called somatic cells gametes (sperm in males,► Chromosome pairs #1-22 eggs AKA ova in females) are called autosomes ► They are created in the► Chromosome pair #23 are gonads (testes in males, called sex chromosomes ovaries in females► XX = female, XY = male
  9. 9. The Cell Cycle► The life cycle of the cell is known as the cell cycle► Itis divided into Interphase and the Mitotic phase
  10. 10. The Cell CycleInterphase is divided into Mitotic phase has 4 phases: 3 sections: Prophase MetaphaseG1: everyday life of cell, Anaphase the cell performs its Telophase job in the body -------------------------------S: DNA replicates Cytokinesis (begins in lateG2: all organelles anaphase, completed at replicate the end of telophase)
  11. 11. Interphase► Early Interphase ► Late Interphase► The cell performs its ► At this point, both the normal functions (G1) chromosomes and the► DNA is in the form of organelles have chromatin so that replicated (S and G2) genes (directions) can ► Cell size has increased be read to make ► Sister chromatids proteins needed by the joined by centromeres cell are present
  12. 12. Interphase
  13. 13. Prophase► Nuclear membrane breaks down exposing chromosomes► Nucleolus disappears► Centrioles migrate to opposite sides of the nucleus► The spindle forms between the centrioles. It is made of microtubules► Chromosomes attach to spindle using their centromere
  14. 14. Metaphase► The spindle fibers pull the chromosomes by their centromeres until they line up down the middle AKA equator of the spindle
  15. 15. Anaphase► The centromeres of the sister chromatids split and the individual chromatids separate, being pulled by the spindle fibers to opposite ends (poles) of the cell► Cytokinesis begins in late anaphase
  16. 16. Telophase► The spindle breaks down► Nuclear membrane returns► Nucleolus reappears► Centriole returns to its normal spot just outside the nucleus► Cytokinesis is completed, 2 daughter cells are now formed
  17. 17. Cytokinesis► This is the process by which the rest of the cell begins to divide► The cell membane begins to pinch in (microfilaments do this) until the cell is completely divided into two cells
  18. 18. Cytokinesis► Begins in late anaphase► Is completed as telophase ends Mitosis+ Cytokinesis Cell Division
  19. 19. Mitosis Summary & Animation http://www.youtube.com/watch?v=s4PaOz7eWS8
  20. 20. Mitosis Review
  21. 21. Which Phase Is It?
  22. 22. Meiosis pp. 196-197► Has two parts: Meiosis ► Meiosis II is simply a I and Meiosis II mitotic division► Meiosis I is slightly different than mitosis ► It is called a in two ways: reduction division *two homologous because… sister chromatid pairs line up on each spindle ► Daughter cells reduce fiber (see p. 196) the # of chromosomes *crossing over from diploid (2n) to occurs in Prophase I haploid (n)
  23. 23. Crossing Over► Occurs in Prophase I► Homologous pairs form a tetrad (4)► They exchange genes AKA genetic recombination► This results in increased genetic diversity of the offspring
  24. 24. Meiosis Summary & Animation http://www.youtube.com/watch?v=D1_-mQS_FZ0
  25. 25. Mitosis vs. Meiosis Mitosis Meiosis Location Somatic Cells Gonads (ovaries or (body cells) testes) Parent Cell Diploid (2n) Diploid (2n)Daughter Cells Diploid (2n) Haploid (n) sex somatic cells cells (gametes)# of Daughter 2 4 Cells?Crossing Over? No Yes, in Prophase I Genetic No YesRecombination?
  26. 26. Mitosis vs. Meiosis
  27. 27. Egg Cell vs. Sperm Cell Production (#, size, motility)3 Polar bodies 1 Ovum (egg) 4 evenly sized sperm with flagella (tails)
  28. 28. Sexual Reproduction + =Haploid (n) Haploid (n) Diploid (2n) Gamete Gamete ZygoteOva (egg) Sperm AKA Junior!
  29. 29. Chromosomal Mutations ► Otherchromosomal► Down Syndrome is mutations include: caused by a trisomy of chromosome #21  Duplication► This is due to a  Deletion (part of nondisjunction of chromosome breaks off) sister chromatids  Inversion (breaks off, during anaphase of reattaches upside down) meiosis when they are supposed to separate  Translocation (breaks off, reattaches on another chromosome)
  30. 30. Diagnosis► An amniocentesis takes cells from the developing fetus (dead skin cells floating in the amniotic fluid)► A picture of the chromosomes called a karyotype is taken► Chromosomal abnormalities can be seen (not individual genes)
  31. 31. Karyotypes
  32. 32. Normal Cells vs. Cancer Cells Normal Cells Cancer CellsGenetic factors (tumor Other genetic factors calledsuppressor genes) can oncogenes can encouragekeep cell cycle in check. cell cycle/mitosis and therefore lead to cancer.Cell cycle regulated by many Cancer cells either make theirproteins/chemicals (called own regulatorygrowth factors) so that cell proteins/chemicals (growthdivision is staggered (not all factors) or don’t respond tocells going through cell the regular ones and godivision at one time). At any through cell divisiongiven time, some cells are repeatedly without any regarddoing their job! to what other cells are doing/the job to be performed.
  33. 33. Normal Cells vs. Cancer Cells Normal Cells Cancer CellsNormal cells show density Cancer cells do not showdependent inhibition density dependentwhich means that they stop inhibition which means theydividing once they hit/touch continue to divide even whenother cells. they are crowding other cells, leading to the formation of a tumor. This prevents nearby cells from doing their jobs well. Tumors are classified as either benign or malignant (actively diving/growing).
  34. 34. Normal Cells vs. Cancer CellsNormal Cells Cancer CellsNormal cell growth/division is also Cancer cells are able to recruitlimited by their resources…they blood vessels, hogging resourcesneed energy to do these things and that allow the tumor to grow biggerthat requires nutrients and oxygen while at the same time deprivingfrom the blood supply which is other nearby cells of nutrients. Thisshared among all cells. is called angiogenesis.Normal cells show anchorage Cancer cells in malignant tumorsdependence which means they are able to metastasize. Thismust be attached to their neighbors means that they are able to detachin order to grow/survive/divide from their parent tissue, enter the blood stream and travel to a new site, reattach and continue growing in the new area, disrupting the activity of multiple areas/tissues of the body, keeping cells from doing their jobs well.
  35. 35. Traditional Cancer Treatment OptionsSurgery Localized removal of cancerous cells (tumor)Radiation therapy Used to kill cancer cells60-75% of all cancer over a more diffuse areapatients undergo RT and/or to kill any cancerwith many severe side cells left after surgicaleffects removal of a tumorChemotherapy The use of strong chemicals to kill rapidly dividing cells. This includes both cancer cells and some normal cells (hair follicles)
  36. 36. Other Cancer Treatment OptionsImmunotherapy Enhances body’s naturalEffective only for some immune response tocancers, not all kill/suppress cancer cellsHormonal Therapy Uses strong steroids to suppress hormones thatEffective only for some stimulate specific cancerscancers, not all (ex: tamoxifen for breast cancer)Proton Therapy A type of radiationFDA approved only since therapy that targets2001, research on tumor cells more directlyeffectiveness and side than RT, reducing theeffects continues, $$$$ impact on normal cells
  37. 37. Helpful Resource:► http://www.cancerquest.org/cell-division- mitosis.html  This website has great animations and explanations comparing/contrasting typical cell division with cancer cell division.

×