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BIO301: Cell Biology

Unit 7: Mitosis and Cytokinesis   Every cell in your body has the capacity to divide and make new cells. Mitosis is the process by which one cell turns into two identical cells. Because of mitosis, most cells in your body don’t live past a few months. In other words, despite your chronological age, your body is really just a few months old!

Mitosis is divided into four phases. This unit will carefully explore each phase, ending with cytokinesis, whereby the cell membrane will pinch itself off and split in half in order to produce two separate cells.

Unit 7 Time Advisory
Completing this unit will take you approximately 7.5 hours.

☐    Subunit 7.1–7.6: 5 hours

☐    Subunit 7.7: 30 minutes

☐    Assessment: 2 hours

Unit7 Learning Outcomes
Upon completion of this unit, you will be able to - identify what major cellular events occur at each phase of the mitotic cell cycle and during cytokinesis; - distinguish between open and closed mitosis; and - describe how to visually identify the phases of the mitotic cycle.

  • Reading: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates: Professor Geoffrey Cooper’s The Cell: A Molecular Approach: “The Events of M Phase” Link: National Center for Biotechnology Information’s Bookshelf: Sinauer Associates: Professor Geoffrey Cooper’s The Cell: A Molecular ApproachThe Events of M Phase (HTML)

    Instructions: Read this section, along with all associated figures (Figs. 14.23, 14.25, 14.27, 14.28–14.31). This reading will cover the topics outlined in subunits 7.1–7.7, and all inclusive subunits.

    Reading this text and taking notes should take approximately 2 hours.

    Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

  • Lecture: University of California, Berkeley: Professor David G. Drubin’s “Mitosis and Cell Division” Link: University of California, Berkeley: Professor David G. Drubin’s Mitosis and Cell Division (YouTube)

    Also available in:
    iTunes U

    Instructions: Watch this lecture. Note that this lecture covers topics outlined in subunits 7.1–7.7, and all inclusive subunits.

    Watching this lecture and taking notes should take approximately 2 hours.

    Terms of Use: This resource is released under a Creative Commons Attribution-NonCommercial-NoDerivs Works 3.0 Unported License. It is attributed to the University of California, Berkeley and the original version can be found here.

  • Reading: National Center for Biotechnology Information’s Bookshelf: W.H. Freeman: Professor Harvey Lodish et al.’s Molecular Cell Biology, 4e: “Microtubule Dynamics and Motor Proteins during Mitosis.” Link: National Center for Biotechnology Information’s Bookshelf: W.H. Freeman: Professor Harvey Lodish et al.’s Molecular Cell Biology, 4e: Microtubule Dynamics and Motor Proteins during Mitosis.” 
     
    Instructions: Read this section, along with associated figures (Figs. 19-34–19-37 and 19.39–19.48. This will cover material in subunits 7.2–7.7.

    Reading this text and taking notes should take approximately 1 hour.

    Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

7.1 Open Mitosis and Closed Mitosis   This subunit is covered by the Cooper reading and video assigned beneath the unit 7 introduction. Focus on the subsection “Dissolution of the Nuclear Envelope” with associated figure (Fig. 8.30).

7.1.5 Anaphase A   This subunit is covered by the Cooper reading and video assigned beneath unit 7. This subunit is also covered by the Lodish reading assigned beneath unit 7. Focus on the “Microtubule shortening during Anaphase A” section.

7.2 Prophase   This subunit is covered by the reading and video assigned beneath the Unit 7 introduction. Focus on the “Stages of Mitosis” section of the reading.

7.2.1 Nuclear Condensation and Condensin   This subunit is covered by the Cooper reading and video assigned beneath unit 7. Focus on the “MPF and Progression to Metaphase” section of the reading. This subunit is covered by the Lodish reading assigned beneath unit 7. Focus on the first section and the “The Kinetochore is a specialized attachment site at the chromosome centromere” section.

7.2.2 Cytoplasmic Changes   This subunit is covered by the Cooper reading and video assigned beneath unit 7. Focus on the “MPF and Progression to Metaphase” section of the reading.

7.3 Prometaphase   This subunit is covered by the Cooper reading and video assigned beneath unit 7. Focus on the subsection “Stages of Mitosis.” This subunit is covered by the Lodish reading assigned beneath unit 7. Focus on the “Kinetichores generate the force for poleward chromosome movement” section.

7.3.1 Nuclear Envelope   This subunit is covered by the Cooper reading and video assigned  beneath unit 7. Focus on the “MPF and Progression to Metaphase” section of the reading. This subunit is covered by the Lodish reading assigned beneath unit 7. Focus on the “Astral Microtubules determine where cytokinesis takes place” section.

7.3.2 Spindle Assembly   This subunit is covered by the Cooper reading and video assigned beneath unit 7. Focus on the subsection “Stages of Mitosis.” This subunit is covered by the Lodish reading assigned beneath unit 7. Focus on the “Formation of poles and capture of chromosomes are key events in spindle assembly” section.

7.3.3 Chromosome Attachment   This subunit is covered by the Cooper reading and video assigned  beneath unit 7. Focus on the “Stages of Mitosis” section of the reading. This subunit is covered by the Lodish reading assigned beneath unit 7. Focus on the “The kinetochore is a specialized attachment site at the chromosome centromere” section.

7.4.1 Metaphase Plate   This subunit is covered by the Cooper reading and video assigned beneath unit 7. Focus on the “MPF and Progression to Metaphase” section of the reading. This subunit is also covered by the Lodish reading assigned beneath unit 7. Focus on the “Kinetochores generate the force for poleward chromosome movement” section.

7.4.2 Chromosomal Oscillations and Microtubule Flux   This subunit is also covered by the Lodish reading assigned beneath unit 7. Focus on the section titled “Kinetochores Generate the Force for Poleward Chromosome Movement."

7.5 Anaphase   This subunit is covered by the Cooper reading and video assigned beneath unit 7. Focus on the “Proteolysis and the Inactivation of MPF: Anaphase and Telophase” section of the reading. This subunit is also covered by the Lodish reading assigned beneath unit 7. Focus on the “During Anaphase chromosomes separate and the spindle elongates” section.

7.5.2 Anaphase B   This subunit is covered by the Cooper reading and video assigned beneath unit 7. This subunit is also covered by the Lodish reading assigned beneath unit 7. Focus on the “Spindle elongation during anaphase B” section. Anaphase A is the earlier of the two anaphase phases, when there is a shortening of the microtubules but no actual separation of chromosomes or ATP usage. Anaphase B refers to the   process of separating the two poles of chromosomes; it also requires ATP for energy.

7.6 Telophase   This subunit is covered by the Cooper reading and video assigned beneath unit 7. Focus on the “Proteolysis and the Inactivation of MPF: Anaphase and Telophase” section of the reading.

7.7 Cytokinesis   This subunit is covered by the Cooper reading and video assigned beneath unit 7. Focus on the “Cytokinesis” section of the reading. This subunit is also covered by the Lodish reading assigned beneath unit 7. Focus on the subsection ”Astral Microtubules Where Cytokinesis Takes Place.”

7.7.1 Contractile Ring   This subunit is covered by the Cooper reading and video assigned beneath unit 7. Focus on the “Cytokinesis” section of the reading. This subunit is also covered by the Lodish reading assigned beneath unit 7. Focus on the “Astral microtubules determine where cytokinesis takes place” section.

7.7.2 Variations in Bacteria   - Assessment: The Saylor Foundation’s “Unit 7 Quiz” Link: The Saylor Foundation’s Unit 7 Quiz” (HTML)
 
Instructions: Please complete the linked quiz to test your knowledge of the material covered in Unit 7.

 Completing this assessment should take approximately 1 hour.
  • Reading: David Krogh’s Biology, A Guide to the Natural World: “Introduction to Genetics, Mitosis, and Cytokinesis” Link: Prentice Hall: David Krogh’s Biology, A Guide to the Natural World: Introduction to Genetics, Mitosis, and Cytokinesis (HTML)
     
    Instructions: Read subsection 9.5, “Variations in Cell Division.”

    Reading this text and taking notes should take approximately 30 minutes.
     
    Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

  • Assessment: University of Arizona’s Biology Project: “Cell Biology” Link: University of Arizona’s Biology Project: Cell Biology (HTML)

    Instructions: In the “Cell Cycle and Mitosis” tutorial, under “Test Yourself (11 problems)”, answer questions 1–11.

    Completing this assessment should take approximately 1 hour.

    Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.