#Question id: 5145
#Unit 5. Developmental Biology
Doris Taylor’s research group used detergents to remove all the cells from a cadaveric rat heart, which left behind the natural extracellular matrix. Proteins such as fibronectin, collagen, and laminin held together the rest of the extracellular matrix and maintained the intricate shape of the heart. The researchers then infused this extracellular matrix scaffold with cardiomyocyte progenitor cells. Surprisingly, these cells differentiated and organized into a functionally contracting “recellularized” heart. The behavior of extracellular matrix scaffold can promote the differentiation and rebuilding of a beating heart is analogous to which of the interactions?
#Question id: 5146
#Unit 5. Developmental Biology
Choose the correct match.
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Process |
Definition |
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a. Epithelial-mesenchymal transition |
i. The phenomenon, whereby cells intercalate to narrow the tissue and at the same time lengthen it. |
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b. De-adhesion |
ii. The process in which cells that had formerly been part of an epithelium lose their attachments and become individual, migrating cells. |
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c. Permissive interaction |
iii. The cadherins that couple epithelial cells together are degraded, thereby allowing the cells to become free from their neighbors. |
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d. convergent extension |
iv. The responding tissue has already been specified and needs only an environment that allows the expression of these traits. |
#Question id: 5147
#Unit 5. Developmental Biology
What is the dissimilarity amongst "fate" and "specification"?
#Question id: 5236
#Unit 5. Developmental Biology
Following statements regarding to signaling pathways that control the properties of germline stem cells in drosophila.
A. The signaling molecules—the TGF-β-family proteins Dpp and Gbb as well as Hedgehog (Hh)—are maintain the self -renewal property of germline stem cells by the repression of differentiation factor.
B. Both E-cadherin and Arm are important in maintaining the germline stem-cell niche and regulate the proliferation of stem cells.
C. The signaling molecules—the TGF-β-family proteins Dpp and Gbb as well as Hedgehog (Hh)—are maintain germline stem cell
niche as well as self-renewal property.
D. Both E-cadherin and Arm are important in maintaining the self -renewal property of germline stem cells by the repression of differentiation factor.
Which of the following is correct?
#Question id: 5237
#Unit 5. Developmental Biology
Match the following stem cell type (Column I) with their niche location (Column II).
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Column I |
Column II |
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A. Intestine |
i. Bone marrow |
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B. Hematopoietic stem cells |
ii. Bulge |
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C. Hair follicle |
iii. Testes |
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D. Sperm |
iv. Base of small intestinal crypts |
Which of the following is correct?
#Question id: 5238
#Unit 5. Developmental Biology
all tissue types possess a unique stem cell niche, and despite many differences among the niche architecture of different tissues, several common principles of stem cell regulation can be applied to all environments. These principles involve extracellular mechanisms leading to intracellular changes that regulate stem cell behavior.
|
Column A |
Column B |
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I. Extracellular regulatory mechanisms |
i. Regulation by endocrine, paracrine, or juxtacrine mechanisms |
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II. Intracellular regulatory mechanisms |
ii. Regulation by a network of transcription factors |
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iii. Epigenetic regulation |
|
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iv. Regulation by cell-to-cell and cell-to-matrix adhesions |
|
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v. Regulation by cytoplasmic determinants |
Match the following regulatory mechanism (column A) with the factors that regulate stem cell behavior (column B).