1 / 32

The Cell Cycle Mitosis & Cancer

The Cell Cycle Mitosis & Cancer. Cell reproduction in multicellular and unicellular organisms. Unicellular: reproduce by binary fission , asexual reproduction Multicellular: reproduce by mitosis ; process of growth and repair. Cellular Reproduction. Chapter 9. 9.1 Cellular Growth.

marriottj
Download Presentation

The Cell Cycle Mitosis & Cancer

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. The Cell Cycle Mitosis & Cancer

  2. Cell reproduction in multicellular and unicellular organisms • Unicellular: reproduce by binary fission, asexual reproduction • Multicellular: reproduce by mitosis; process of growth and repair

  3. Cellular Reproduction Chapter 9 9.1 Cellular Growth • As the cell grows, its volume increases much more rapidly than the surface area. • What’s the problem? • The cell would not be able to supply itself with nutrients and expel all waste products.

  4. Cellular Reproduction Chapter 9 9.1 Cellular Growth Ratio of Surface Area to Volume

  5. Cellular Reproduction Chapter 9 9.1 Cellular Growth The Cell Cycle • Cell division prevents the cell from becoming too large. • It also is the way the cell reproduces so that you grow and heal certain injuries. • Cells reproduce by a cycle of growing and dividing called the cell cycle.

  6. The cell cycle is an orderly series of events in which a cell duplicates its contents and divides to produce two new, identical daughter cells. • Different cells divide at different rates!

  7. The price you pay - stages of alcohol-induced liver damage Fatty Liver Liver Fibrosis Cirrhosis Growth of connective tissue destroys liver cells. Damage is irreversible. Deposits of fat cause liver enlargement. Strict abstinence can lead to a full recovery. Scar tissue forms. Recovery is possible, but scar tissue remains. The length of the cell cycle differs. • Liver cells divide once every year or so.

  8. Epithelial cells lining the gut divide more than once a day.

  9. Cellular Reproduction Chapter 9 9.1 Cellular Growth • Interphase is the stage during which the cell grows, carries out cellular functions, and replicates DNA. [Most time - Most cells!] • Nucleic Division (Mitosis/Meiosis) is the stage of the cell cycle during which the cell’s nucleus and contents divide. • Cytokinesisis the cutting of the cell’s cytoplasm, creating a new cell.

  10. 9.1 Cellular Growth The Stages of Interphase • The first stage of interphase, G1 • The cell is GROWING and carrying out normal cell functions

  11. Cellular Reproduction Chapter 9 9.1 Cellular Growth The Second Stage of Interphase, S • S = “synthesis” • DNA is COPIED, or synthesized, so that the cell can split.

  12. Cellular Reproduction Chapter 9 9.1 Cellular Growth The Third Stage of Interphase, G2 • The cell prepares for the division of its nucleus with final checkpoints.

  13. Chromosomes • Carriers of genetic material (DNA) found in nucleus • Information must be copied and passed to future generations

  14. Usually DNA exists as chromatin which is long, winding strands which condense into chromosomes before dividing

  15. Chromosome structure • Chromosomes are made up of two chromatids which are held together with a centromere • Human chromosome number: • 46 in somatic body cells (diploid) • 23 in gamete sex cells (haploid)

  16. Replicated chromosomes remain bound together = sister chromatids.

  17. Cellular Reproduction Chapter 9 9.3 Cell Cycle Regulation Normal Cell Cycle • Cell regulators - Chemical signals telling the cell to divide (or not to divide) • Cyclin, CDK, Checkpoints

  18. Cell Division • Cell cycle consists of three main stages: • Interphase • Mitosis • Cytokinesis • Mitosis has four phases: • Prophase • Metaphase • Anaphase • Telophase

  19. Chromatin coils into chromosomes, nucleus disappears Centrioles form Spindle fibers form Longest phase of mitosis (not cell cycle) Prophase

  20. Meta = “Middle” Chromosomes line up in the middle of the cell Spindle fibers forms across the celland attach to centromeres Metaphase

  21. Spindle fibers shorten and pull the chromosomes apart to opposite ends Chromosome halves are referred to as chromatids Anaphase

  22. Chromosomes unwind back into chromatin and nucleus reforms In animal cells, plasma membrane (cell membrane) begins to pinch in. Telophase

  23. Animal Cell Cell membrane creates a cleavage furrow by pinching in to form the 2 new daughter cells Plant Cell Cell plate forms between two nuclei to form the 2 new daughter cells Cytokinesis The cytoplasm divides. Two nuclei, two new cells.

  24. Cytokinesis: Plant v. Animal Cleavage furrow in animal cell Cell plate in plant cell

  25. Animal Cell Reproduction (Mitosis) Plant Cell Reproduction (Mitosis)

  26. Cellular Reproduction • Cancer cells can kill an organism by crowding out normal cells, resulting in the loss of tissue function. Chapter 9 9.3 Cell Cycle Regulation Abnormal Cell Cycle: Cancer • Cancer is the uncontrolled growth and division of cells.

  27. Cancer • The changes that occur in the regulation of cell growth and division of cancer cells are due to mutations. • Carcinogens are substances and agents that are known to cause cancer

  28. Apoptosis • Programmed cell death • Occurs in trees cutting off a leaf • Occurs in the development of hands and feet (cells grow in the space between the fingers, they then die) • Hopefully occurs when regulators sense something “wrong” prior to cell division

  29. Apoptosis

More Related