#Question id: 5144
#Unit 5. Developmental Biology
Following statements regarding to noncanonical wnt pathways.
A. The planar cell polarity, or PCP, pathway functions to regulate the actin and microtubule cytoskeleton, thus influencing cell shape, and often results in bipolar protrusive behaviors necessary for a cell to migrate.
B. Wnts (such as Wnt5a and Wnt11) can activate Disheveled by binding to a different receptor (Frizzled paired with Ror instead of Lrp5), and this Ror receptor complex phosphorylates Disheveled in a way that allows it to interact with Rho GTPases.
C. Wnt/PCP signaling through cytoskeleton control can direct cells to divide in the different plane ( forming upper and lower tissue compartments) and to move within that different plane.
D. the Wnt/calcium pathway leads to the release of calcium stored within cells, and this released calcium acts as an important secondary messenger to activates a phospholipase (PLC) whose enzyme activities release a compound that in turn releases calcium ions from the cytosol.
Which of the following is incorrect?
#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.
|
Process |
Definition |
|
a. Epithelial-mesenchymal transition |
i. The phenomenon, whereby cells intercalate to narrow the tissue and at the same time lengthen it. |
|
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. |
|
c. Permissive interaction |
iii. The cadherins that couple epithelial cells together are degraded, thereby allowing the cells to become free from their neighbors. |
|
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).
|
Column I |
Column II |
|
A. Intestine |
i. Bone marrow |
|
B. Hematopoietic stem cells |
ii. Bulge |
|
C. Hair follicle |
iii. Testes |
|
D. Sperm |
iv. Base of small intestinal crypts |
Which of the following is correct?