#Question id: 7171
#Unit 5. Developmental Biology
Following statements are regarding to the early development in sea urchin.
A. most cells of the 16-cell embryo, the large micromeres are autonomously specified.
B. large micromeres inherit maternal determinants that were deposited at the vegetal pole of the egg; these become incorporated into the large micromeres at the fourth cleavage.
C. The conditionally specified large micromeres are now able to produce paracrine and juxtacrine factors that autonomously specify the fates of their neighbors.
D. Large micromeres become skeletogenic mesenchyme cells that will leave the blastula epithelium, enter the blastocoel, migrate to particular positions along the blastocoel wall, and then differentiate into the larval skeleton.
Which of the following statement is false?
#Question id: 7172
#Unit 5. Developmental Biology
Transplantation of different regions of the presomitic mesoderm (PSM) to the limb field causes changes in limb size. Following statements are:
A. Transplanting PSM from the level of the presumptive forelimb to the flank (region between the forelimb and hindlimb) results in a larger forelimb bud.
B. Transplantation of PSM from the flank region to the level of the presumptive forelimb results in a smaller forelimb bud.
C. Transplanting PSM from the level of the presumptive forelimb to the flank (region between the forelimb and hindlimb) results in a smaller forelimb bud.
D. Transplantation of PSM from the flank region to the level of the presumptive forelimb results in a larger forelimb bud.
Which of the following combination are correct?
#Question id: 7173
#Unit 5. Developmental Biology
Normally, the FgfR3 protein (a receptor tyrosine kinase) is activated by a fibroblast growth factor and signals the chondrocytes to stop dividing and begin differentiating into cartilage. This signal is mediated by the Stat protein, which is phosphorylated by activated FgfR3 and then translocated into the nucleus. Inside the nucleus, Stat activates the genes encoding a cell cycle inhibitor, the p21 protein. The mutation in FgfR3 causes the lethal condition thanatophoric dysplasia. This condition may be achieved by:
A. Mutations in the extracellular domain of the FgfR3 protein
B. Mutations in the tyrosine kinase intracellular domain of the FgfR3 protein
C. Mutations in the transmembrane domain of the FgfR3 protein
Which of the following is correct?
#Question id: 7174
#Unit 5. Developmental Biology
According to graph, which of the following statement is incorrect regarding to bicoid protein in drosophila?
#Question id: 7175
#Unit 5. Developmental Biology
The primitive streak is derived from epiblast cells and the central cells of Koller’s sickle. As the primitive streak extends rostrally, Henson’s node is formed. Following are few statements regarding this:
A. As endodermal ingression continues, the primitive streak starts to regress, moving Henson’s node from near the center of the area pellucida to a more posterior position.
B. As endodermal ingression continues, the primitive streak starts to regress, moving Henson’s node from near the periphery of the area pellucida to a more posterior position.
C. As mesodermal ingression continues, the primitive streak starts to regress, moving Henson’s node from near the center of the area pellucida to a more posterior position.
D. As mesodermal ingression continues, the primitive streak starts to regress, moving Henson’s node from near the periphery of the area pellucida to a more anterior position.
Which of the following statements are correct?
#Question id: 7176
#Unit 5. Developmental Biology
The
metamorphic changes of frog development are brought about by following events.
(A)
the secretion of the hormone thyroxine (T4) into the blood by the thyroid gland
(B)
the degradation of T3 in the target tissues
(C)
the conversion of (T4) into the more active hormone, triiodothyronine (T3) by
the target tissues
Which of the following series is correct?