1 / 55

10.1 Pre-Read Questions

10.1 Pre-Read Questions. Name 2 limitations to cell growth. How does DNA limit cell growth? Why is the ratio of surface area to volume important? Describe the process of cell division. Ch 10: Cell Growth and Division. 10.1: Cell Growth. Cells. Does not continue to grow bigger

valentine
Download Presentation

10.1 Pre-Read Questions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. 10.1 Pre-Read Questions • Name 2 limitations to cell growth. • How does DNA limit cell growth? • Why is the ratio of surface area to volume important? • Describe the process of cell division.

  2. Ch 10: Cell Growth and Division 10.1: Cell Growth

  3. Cells • Does not continue to grow bigger • Cells just continue to produce more cells

  4. Limits to Cell Growth • 2 main reasons • Larger a cell becomes, the more demands the cell places on its DNA

  5. Limits to Cell Growth • 2 main reasons 2. Cell has more trouble moving enough nutrients and wastes in and out of cell

  6. Reason #1 DNA “overload” • DNA = information that controls a cell’s function • if cells grow, DNA does not make extra copies • DNA would not be able to serve the needs of the cell

  7. Reason #2: Exchanging Materials • how fast materials leave or enter the cell depends on surface area • food and oxygen depend on cell volume

  8. Ratio of Surface Area to Volume • as surface area increases, its volume increases at a faster rate

  9. Ratio of Surface Area to Volume Consequence = cells have a more difficult time to move needed materials in and waste products out

  10. Cell Division • how cells reproduce • one cell divides into 2 new cells • daughter cells

  11. Cell Division before cell division - cell copies DNA • Each daughter cell gets own copy of DNA

  12. 10.2A 12 / 5 / 06

  13. 2 Stages • Mitosis = division of the cell nucleus • Cytokinesis = division of the cytoplasm

  14. Mitosis • asexual • source of new cells

  15. Chromosomes • carries the genetic information • consists of DNA • cells have specific number of chromosomes

  16. Chromosome • not visible until cell division • replicated before cell division • chromosomes change form to chromatids

  17. Chromatids • Separate from each other and go into daughter cells • attached at a centromere • located near the middle of the chromatids

  18. Centromere Chromatid

  19. Cell Cycle • cell reproduction • forms two daughter cells • in between period = interphase

  20. Cell Cycle: 4 phases • consists of 4 phases • M phase = mitosis and cytokinesis • S phase = chromosome replication (S = synthesis) • G1 and G2 (G = gap) -- growth and activity

  21. Interphase • 3 of the 4 phases occur • G1 • S phase • G2

  22. G1 Phase • cell growing • increase in size and synthesize new proteins and organelles

  23. S Phase • chromosome replication • proteins synthesized

  24. G2 Phase • DNA replication complete at beginning • shortest phase

  25. G2 Phase • organelles produced • prepare for cell division

  26. 10.2 Post Read Questions • Describe the 2 stages of cell division. • Draw a chromosome and label and describe its parts. • What are the different phases of interphase? Describe each one. • What is the cell cycle?

  27. 10.2 B 12 / 06 / 06

  28. Interphase • In between periods of cell division • Cell growth and DNA replication occur

  29. Prophase • first and longest phase (50%-60%) • chromosome becomes visible • centrioles take position on opposite sides of nucleus at the centrosome

  30. Prophase • Centrioles lie in centrosome so they can organize the spindle • Spindle = fanlike microtubule structure that helps separate the chromosomes

  31. Prophase • end = chromosomes coil and nuclear envelope break down

  32. Metaphase • lasts only a few minutes • chromosomes line up across the center of the cell

  33. Metaphase (cont) • microtubules connect the centromere of each chromosome to the two poles of the spindle

  34. Anaphase • centromeres that join the sister chromatids split into individual chromosomes and are moved apart to opposite poles

  35. Telophase • chromosomes become dense material • spindle breaks apart • nucleolus appears

  36. Cytokinesis • Division of cytoplasm • usually occurs the same time as telophase • Animal Cell = cell membrane draw inward and pinched off • Plant cell = cell plate forms midway between the 2 nuclei; cell wall appears

  37. T I P M A ROPHASE ETAPHASE NAPHASE ELOPHASE NTERPHASE

  38. A B E C D Put the pictures in order

  39. A B E C D ANSWER

  40. Ch 10 Review Questions (Cont) • What is cytokinesis? When does it occur? • Compare how cytokinesis works between animal and plant cells. • Describe metaphase. • Describe anaphase. • If you were to look at a picture of telophase and anaphase, how can you distinguish the difference between the two?

  41. 10.3 12 / 7 / 06

  42. Review: Cell Cycle • Preparing for Cell Division • INTERPHASE • G1 • S • G2

  43. Review: Cell Cycle • Steps of Cell Division • Mitosis • Prophase • Metaphase • Anaphase • Telophase / Cytokinesis

  44. Look at Figure 10.7 • Observe what is going on • What is happening in each step?

  45. Cyclin • protein • regulates the timing of the cell cycle in eukaryotic cells

  46. Regulatory Proteins • Two types • Internal Regulators • External Regulators

  47. Internal Regulators • proteins that respond to events inside the cell • signals cell cycle to continue ONLY WHEN OTHER THINGS ARE COMPLETE

More Related