#Question id: 7209
#Unit 5. Developmental Biology
Following statements are related to the Epigenetic regulation of Hox gene expression in the chick limb .
A. Hoxa13 is normally not expressed during early limb bud outgrowth.
B. Hoxa13 is normally expressed during early limb bud outgrowth.
C. Inhibition of histone deacetylases with a TSA-coated bead implanted into the early limb bud results in precocious Hoxa13 expression and specifically reduced skeletal elements of the zeugopod
D. Inhibition of HAT proteins with a TSA-coated bead implanted into the early limb bud results in Hoxa13 expression and specifically reduced skeletal elements of the zeugopod
E. The epigenetic hold on gene Hoxa13 expression to allow the necessary time for zeugopod development.
F. The epigenetic hold on gene Hoxa13 expression to allow the necessary time for autopod development.
Which of the following combinations are correct?
#Question id: 7210
#Unit 5. Developmental Biology
Model for limb patterning by opposing gradients of retinoic acid (blue shading) and of FGFs and Wnts (pink shading). According to this graph, Which of the following statements are correct?
#Question id: 7211
#Unit 5. Developmental Biology
Choose the correct match.
|
Germ layers specifying
signals |
Result |
|
a.
If either Nodal or Vg1 signaling is
blocked |
i.
No ectoderm induction |
|
b.
If vegT mRNA depleted |
ii.
No endoderm induction |
|
c.
If smad2 phosphorylation inhibited |
iii.
No mesoderm induction |
|
|
iv.
Ectoderm only |
#Question id: 7212
#Unit 5. Developmental Biology
The regeneration blastema forms from pluripotent stem cells called clonogenic neoblast. If cNeoblasts are essential for regeneration, their total loss should prevent regeneration. Following statements are made in respect to planaria regeneration are given below.
(A) The gene sigma/zeta is expressed by all neoblasts and has become the most common marker for their identification across planarian species.
(B) In planaria, Wnt/β-catenin functions to establish dorsal ventral polarity of the regenerating flatworm.
(C) Inhibition of Wnt/β-catenin signaling in regeneration-deficient species yields fully functional regenerated heads.
(D) If β-catenin is eliminated from the posterior (tail-forming) blastema by RNA interference, that blastema will form a tail.
Which of the above statements are true?
#Question id: 7213
#Unit 5. Developmental Biology
Following statements are regarding to the early development of C.elegans (expression of PIE-1):
A. Segregation of PIE-1 determinant into the P1 blastomere at the 2-cell stage
B. The sperm centrosome activates the presence of the PAR-3/PAR-6 complex in the posterior of the egg
C. PIE-1 is degraded in the resulting anterior AB cell, it is preserved in the posterior P1 cell
D. PIE-1 is degraded in the resulting posterior P1 cell, it is preserved in the anterior AB cell
Which of the following combination is incorrect?
#Question id: 7214
#Unit 5. Developmental Biology
The anterior posterior compartment of each segment of drosophila is defined by wingless and engrailed genes. The following statements are given towards explaining their regulation:
A.cells secreting Hedgehog protein activate wingless expression in their neighbors, and the Wingless protein signal, which is received by the cells that secreted Hedgehog, serves to maintain hedgehog (hh) expression.
B.Engrailed protein also acts in an autocrine fashion, maintaining its own expression.
C.The cells expressing engrailed can bind wingless protein because they contain Frizzled, which is the Drosophila membrane receptor protein for Wingless.
D.Binding of Wingless to Frizzled activates the hedgehog signal transduction pathway, resulting in the continued expression of engrailed.
Which of the following option has all the incorrect statements?