Sect 9 Quiz Easy
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Questions and Answers

What is the term used to describe the development history of a cell from its birth to its final differentiation?

  • Cell lineage
  • Cell niche
  • Cell asymmetry
  • Cell fate (correct)

    • Which statement best describes stem cells?

  • Unspecialized cells that can self-renew and differentiate (correct)
  • Cells that only multiply without differentiation
  • Specialized cells that cannot reproduce
  • Differentiated cells from adult tissues

    • What characterizes adult stem cells?

  • Developed from a stem cell in adult tissues (correct)
  • Found only in embryos
  • Totipotent in nature
  • Exclusively pluripotent

    • How can cell fate in an embryo be determined?

    <p>By cell location experiments</p> Signup and view all the answers

    Which of the following is NOT a category of stem cell?

    <p>Invasive stem cells</p> Signup and view all the answers

    What is the primary role of the apoptosome?

    <p>To initiate cell death</p> Signup and view all the answers

    What defines asymmetric cell division?

    <p>Produces daughter cells with different developmental fates</p> Signup and view all the answers

    Which term describes stem cells that can give rise to all cell types of the organism?

    <p>Totipotent</p> Signup and view all the answers

    What type of cells can multipotent cells develop into?

    <p>More than one but not all cell types</p> Signup and view all the answers

    What do transiently amplifying cells do?

    <p>Divide rapidly and produce lineage-restricted progenitor cells</p> Signup and view all the answers

    How frequently does the intestinal epithelium renew itself in adult humans?

    <p>Every 5 days</p> Signup and view all the answers

    What is the role of the niche in stem cell maintenance?

    <p>Maintain a self-renewing population of undifferentiated stem cells</p> Signup and view all the answers

    Where do intestinal stem cells reside?

    <p>At the base of the crypts in the intestinal wall</p> Signup and view all the answers

    What does the Wnt signaling pathway influence in intestinal stem cells?

    <p>Differentiation and self-renewal</p> Signup and view all the answers

    What do Lgr5+ stem cells differentiate into?

    <p>Various differentiated epithelial cells in the villus</p> Signup and view all the answers

    Which stem cells replenish needed blood cells?

    <p>Hematopoietic stem cells</p> Signup and view all the answers

    What type of stem cells are obtained from fetuses?

    <p>Fetal stem cells</p> Signup and view all the answers

    What is the differentiation potential of embryonic stem cells?

    <p>Pluripotent</p> Signup and view all the answers

    At which stage of development are totipotent cells found?

    <p>8-cell stage</p> Signup and view all the answers

    What is the primary characteristic of induced pluripotent stem cells (iPS)?

    <p>Reprogrammed adult cells</p> Signup and view all the answers

    What are the cells found in the inner cell mass of the blastocyst called?

    <p>Embryonic stem cells</p> Signup and view all the answers

    Which of the following statements is true about adult stem cells?

    <p>They are multipotent, except germ-line stem cells.</p> Signup and view all the answers

    Which factors control the pluripotency of embryonic stem cells?

    <p>DNA methylation and transcription factors</p> Signup and view all the answers

    What unique capability do embryonic stem cells have that adult stem cells do not?

    <p>They can reproduce indefinitely in culture.</p> Signup and view all the answers

    What do Lgr5+ cells differentiate into when Notch signaling is present?

    <p>Absorptive enterocytes</p> Signup and view all the answers

    What is the primary function of Paneth cells?

    <p>Providing antimicrobial defense</p> Signup and view all the answers

    Which cells can restore Lgr5+ stem cells following injury?

    <p>Reserve stem cells</p> Signup and view all the answers

    What do telocytes primarily provide in the intestinal environment?

    <p>Growth factors necessary for stem-cell self-renewal</p> Signup and view all the answers

    Which type of cells are specialized in secreting mucus?

    <p>Goblet cells</p> Signup and view all the answers

    What is the role of iPS cells in medical research?

    <p>To understand disease causes and screen drugs</p> Signup and view all the answers

    Which type of cells take up intestinal microbial antigens?

    <p>M cells</p> Signup and view all the answers

    What do symmetric cell divisions produce?

    <p>Two identical daughter cells</p> Signup and view all the answers

    What is required for asymmetric cell division to occur?

    <p>An intrinsic program to generate polarity</p> Signup and view all the answers

    What happens to daughter cells if the mitotic spindle is not appropriately oriented?

    <p>They may have the same fate determinants</p> Signup and view all the answers

    What is one of the steps in generating polarized cells?

    <p>Initiating a signal transduction pathway</p> Signup and view all the answers

    What are cell polarity determinants required for?

    <p>To ensure asymmetric localization for proper cell function</p> Signup and view all the answers

    What triggers apoptosis in vertebrate cells?

    <p>Activation of caspases</p> Signup and view all the answers

    Which of the following is a component of conserved apoptotic pathways?

    <p>Cell membrane receptors</p> Signup and view all the answers

    What is the primary role of trophic factors in vertebrate cells?

    <p>To ensure cell survival</p> Signup and view all the answers

    How is cell polarity reinforced after initial establishment?

    <p>Via reinforcement of cell polarity determinants</p> Signup and view all the answers

    What is the primary role of caspases in cell death?

    <p>To cleave specific intracellular substrates</p> Signup and view all the answers

    What is the outcome of apoptotic cell fragmentation?

    <p>Release of small membrane-bound apoptotic bodies</p> Signup and view all the answers

    Which protein family is involved in the regulation of apoptosis?

    <p>Bcl-2 family</p> Signup and view all the answers

    What triggers the oligomerization of Bax or Bak proteins?

    <p>Environmental stress</p> Signup and view all the answers

    How do pro-apoptotic BH3-only proteins promote apoptosis?

    <p>By binding directly to Bcl-2</p> Signup and view all the answers

    What effect does the binding of extracellular trophic factors have on apoptosis?

    <p>Triggers changes leading to cell survival</p> Signup and view all the answers

    What happens to Bad protein upon phosphorylation?

    <p>It becomes sequestered by 14-3-3 proteins</p> Signup and view all the answers

    Which event triggers the synthesis of the Puma gene?

    <p>DNA damage</p> Signup and view all the answers

    Study Notes

    Stem Cells, Cell Asymmetry, and Cell Death

    • Learning Objectives: After completing this module, students will be able to define apoptosis, apoptosome, asymmetric/symmetric cell division, Bcl-2 family, caspases, cell fate, cell lineage, embryonic stem cells, iPS cells, multipotent, pluripotent, progenitor cells, stem cells, stem-cell niche survival signals, and totipotent.

    • Differentiate different stem cell categories used in biological research & therapy.

    • Discuss key stem cells in the intestinal stem cell niche.

    • Compare apoptosis to necrosis.

    • Text: Lodish et al. (2021), Chapter 22. Discusses the origin of people from Noah's sons. Encourages kindness and love.

    • Cell Lineage: Developmental history of a cell from birth to final division/differentiation into a specific cell type is called cell fate. A cell lineage tracks birth order of cells as they progressively specialize. Examples include cell lineage in C. elegans and all cells in that organism.

    • Stem Cells: Unspecialized cells that self-renew and differentiate into specialized cells are called stem cells. There are four main types:

      • Adult stem cells: Derived from adult tissue, possessing less differentiation potential compared to fetal cells.
      • Fetal stem cells: Derived from fetuses, capable of greater differentiation (compared to adult stem cells).
      • Embryonic stem cells (ESCs): Derived from blastocysts (4-5 days after fertilization) having the most differentiation potential among stem cells.
      • Induced pluripotent stem cells (iPSCs): Adult cells reprogrammed to have stem cell capabilities.

    • Totipotent cells: Human embryos (8-cell stage) are fully capable of forming all tissues (embryonic and extra-embryonic).

    • ES cells: At the blastocyst stage, a distinct inner cell mass forms. These become embryonic stem cells (ES cells) that can generate all embryonic tissues but not extraembryonic tissues (like placenta). ES cells are pluripotent.

    • Pluripotent cells: Can generate all cell types in the body.

    • Multipotent cells: Can develop into multiple cell types, but their differentiation capacity is more limited compared to pluripotent cells.

    Cell Polarity and Asymmetric Cell Division

    • Symmetric cell divisions: Daughter cells are identical to the parent.
    • Asymmetric cell divisions: Daughter cells inherit different components, leading to various shapes or functionalities.

    Cell Death

    • Apoptosis: Programmed cell death. Vertebrate cells require trophic factors for survival. Without these, apoptosis occurs. Apoptosis involves membrane-bound and cytosol regulatory proteins, and specific caspases. Activated caspases cleave intracellular substrates, leading to cell demise. Other proteins (CED-4/Apaf-1) are also involved in this process. Apoptotic cells shrink, condense, and fragment, releasing membrane-bound bodies, which are then engulfed by neighboring phagocytes. This differs from necrosis, where cells swell and burst, releasing intracellular contents causing inflammation.

    Bcl-2 Family & Apoptosis Regulation

    • The Bcl-2 family includes pro- and anti-apoptotic proteins (mostly transmembrane proteins).
    • Pro-apoptotic members: Bax, Bak, Bok, and others. These trigger apoptosis.
    • Anti-apoptotic members: Bcl-2, Bcl-xL, Bcl-w, and others. These inhibit apoptosis.
    • Binding of extracellular trophic factors can trigger changes in interactions between pro- and anti-apoptotic proteins, resulting in cell survival.
    • DNA Damage triggers Puma gene synthesis, which binds to Bcl-2 and promotes Bax-Bax pore formation, initiating apoptosis.

    Fas-Mediated Apoptosis

    • Fas-mediated apoptosis is regulated by extracellular death signals (like tumor necrosis factor and Fas ligand) binding to their receptors. This process oligomerizes associated protein FADD (which then triggers caspase cascade) leading to apoptosis.

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    Related Documents

    2024 Stem Cells, Cell Asymmetry, and Cell Death Notes (BIOL 374)

    Description

    Explore the essential concepts of stem cells, cell asymmetry, and cell death in this quiz. You'll be tested on key topics such as apoptosis, different types of stem cells, and their roles in biological research and therapy. Understand the processes that govern cell fate and lineage through focused questions based on Lodish et al. (2021), Chapter 22.

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