NO RTW

1. Monday, October 16th NO RTW • Objective- I will be able to describe the specific events that occur in each of the stages of the cell cycle (which include the phases of mitosis). • Agenda • Remediation on DIA #2 • Cell cycle worksheet- Read pg. 140 & 141 and complete the worksheet • Homework: • None

2. Everyone put bags AND PHONES up front (you’ll need a pen/cil) • Remediations on the left side of the room • Once you finish the answer sheet raise your hand and I will give you the remediation worksheet • Record how many answers you got correct • When done, raise your hand and give me the answer sheet • You are working independently on your remediation • Non-remediations on right side of room • You are working on the worksheet using the book pgs. 140-141 to help you

3. Tuesday, October 17th RTW Read & Answer Sam’s Puppy • Objective- I will be able to describe the specific events that occur in each of the stages of the cell cycle (which include the phases of mitosis). • Agenda • Probe: Sam’s Puppy • New GOW pg. 44 & New TOC pg. 45 • Cell Cycle Notes pg. 47 • Exit slip • Homework: • None

4. Ch. 5.1- Cell Cycle

5. Stages of the cell cycle • 4 stages • Gap 1 (G1) • Synthesis • Gap 2 (G2) • Mitosis • A cell won’t proceed through the cycle until it’s ready • Prevents errors (cancer)

7. Gap 1 (G1) • First stage of cell cycle • Cell carries out its normal function • Skeletal cells contracts to move joints • Adrenal cells secrete hormones • Intestinal cells absorb nutrients, etc. • Cells increase in size & organelles increase in number • Cells must pass critical checkpoint before proceeding to DNA synthesis

9. Synthesis (S) • Second stage • Synthesis=“combining of parts to make a whole” • Cell makes a copy of its nuclear DNA • Contains 2 complete sets of DNA by end of the S stage

10. Gap 2 (G2) • Third stage • Continues to carry out normal functions • Additional growth occurs • Another critical checkpoint to ensure adequate cell size and that DNA is undamaged.

11. 2

12. Mitosis (M) • Fourth stage • Includes 2 processes • Mitosis= division of the nucleus and its contents • Cytokinesis= division of the cytoplasm • Results in 2 genetically identical daughter cells

13. Cells divide at different rates • Aligned to your body’s need for those cells • In human cells: S, G2, and M stages together take about 12 hours • Cell division is greater in children than adults • Their cell cycles are also shorter • Certain cells, such as neurons and lymphocytes, divide rarely • Usually in G0 stage

14. Ch. 5.3 Regulation of the Cell Cycle

15. External factors • Signals from outside the cell help regulate the cycle • Physical- • ex: cell contact (stops dividing when it touches another cell) • Chemical- • Ex: growth factors (broad group of proteins that stimulate cell division by binding to receptors)

16. normal cell cancer cell bloodstream Cancer • UNCONTROLLED CELL GROWTH! • Benign= remain clustered together and is relatively harmless • Malignant= cancer cells that break away from the tumor and form more tumors

17. Tumors • Harmful because they don’t carry out specialized functions • Tumors in the lung don’t exchange oxygen/CO2 • Tumors in brain don’t transmit information • These clumps require a lot of food and blood supply, but contribute nothing to the body • Will also provide great pressure to surrounding organs

18. Carcinogens • = substances that promote the development of cancer • Ex: • Tobacco smoke • Air pollutants

19. Amoeba Sisters- Cell Cycle & Cancer

20. Exit Slip • Ch. 5.1 assessment pg. 137 • #1-5

21. Wednesday, October 18th RTW pg. 46: What phase are cells in the majority of time? • Objective- I will be able to describe the specific events that occur in each of the stages of the cell cycle (which include the phases of mitosis). • Agenda • Review 5.1 Study Guide & Sam’s Puppy • Mitosis Notes pg. 49 • Amoeba Sisters- Mitosis • Homework: • None

22. Ch. 5.2- Mitosis & Cytokinesis

23. Phases of the Cell Cycle • The cell cycle consists of • Interphase – normal cell activity • The mitotic phase – cell division

24. 100 µm 200 µm 20 µm (a) Reproduction. An amoeba, a single-celled eukaryote, is dividing into two cells. Each new cell will be an individual organism (LM). (b) Growth and development. This micrograph shows a sand dollar embryo shortly after the fertilized egg divided, forming two cells (LM). (c) Tissue renewal. These dividing bone marrow cells (arrow) will give rise to new blood cells (LM). Functions of Cell Division

25. Chromosome • = one long continuous thread of DNA that consists of numerous genes & regulatory info. • Your body cells have 46 chromosomes • 23 from Mom & 23 from Dad • DNA wraps around proteins (histones) to keep it condensed and organized

27. Chromosomes • Chromatins becomes more condensed as a cell goes into mitosis • Chromatid= one half of the duplicated chromosome • 2 chromatids= sister chromatids • The centromere holds the sister chromatids together • Telomers= are at the ends of DNA molecules & protect the genes from damage

28. Mitosis • 4 phases of mitosis • Occurs in body cells resulting in two genetically identical nuclei • After mitosis, cytokinesis (splitting of cytoplasm) occurs

29. PROPHASE Aster Early mitoticspindle Centromere Chromosome, consistingof two sister chromatids Prophase • Chromatid condenses • Nuclear envelope breaks down • Nucleolus disappears • Centrosomes and centrioles migrate to opposite ends of the cell • Spindle fibers start to grow

30. METAPHASE Metaphaseplate Spindle Centrosome at one spindle pole Metaphase • Spindle fibers attach to each chromosome • Chromosomes align along the cell equator (metaphase plate)

31. ANAPHASE Daughter chromosomes Anaphase • Sister chromatids separate • Spindle fibers shorten which pulls sister chromatids away from each other & towards opposite ends of the cell

32. TELOPHASE AND CYTOKINESIS Cleavagefurrow Nucleolusforming Nuclear envelopeforming Telophase • Complete set of identical chromosomes are at each pole of the cell • Nuclear membrane starts to form • Chromosomes begin to uncoil • Spindle fibers fall apart

33. Cytokinesis • Cytoplasm divides into two cells and completes a full stage of the cell cyle • Different in plant & animal cells • Animal cells- the membrane furrows • Plant cells- a cell plate forms since the cell wall is too rigid for the cell to furrow (or pinch together)

34. 100 µm Cleavage furrow Vesiclesforming cell plate 1 µm Wall of patent cell Cell plate New cell wall Contractile ring of microfilaments Daughter cells (a) Cleavage of an animal cell (SEM) (b) Cell plate formation in a plant cell (SEM) Daughter cells

35. Amoeba Sisters- Mitosis

36. Thursday, October 19th RTW pg. 46: What happens when cells aren’t regulated? • Objective- I will be able to describe the specific events that occur in each of the stages of the cell cycle (which include the phases of mitosis). • Agenda • Finish Amoeba Sisters- Mitosis • Mitosis Foldable • Homework: • None

37. Friday, October 20th RTW pg. 46: Which phase of mitosis are the chromosomes lined up in the middle? • Objective- I will be able to describe the specific events that occur in each of the stages of the cell cycle (which include the phases of mitosis). • Agenda • Asexual Reproduction Notes • Study Guide • Homework: • None

38. KEY CONCEPTMany organisms reproduce by cell division.

39. parent cell DNA duplicates cell begins to divide daughter cells Binary fission is similar in function to mitosis. • Asexual reproduction is the creation of offspring from a single parent. • Binary fission produces two daughter cells genetically identical to the parent cell. • Binary fission occurs inprokaryotes.

40. Asexual reproduction is an advantage in consistently favorable conditions. • Sexual reproduction is an advantage in changing conditions. • Environment determines what form of reproduction is most advantageous.

41. Hydra bud Yeast Some eukaryotes reproduce through mitosis. • Budding forms a new organism from a small projection growing on the surface of the parent.

42. Fragmentation is the splitting of the parent into pieces that each grow into a new organism. • Vegetative reproduction forms a new plant from the modification of a stem or underground structure on the parent plant.

43. Parthenogenesis • Type of asexual reproduction that occurs without fertilization

44. Assignments • Study Guide 5.4 pg. 49 • (when done raise your hand to be graded) • Complete Cancer cell worksheet and turn it in • Finish Mitosis foldable