#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?
#Question id: 7177
#Unit 5. Developmental Biology
Following statements are regarding to the early development in nematodes. Which of the following is incorrect?
#Question id: 7178
#Unit 5. Developmental Biology
In sea urchin, the large micromeres are autonomously specified. They inherit maternal determinants that were deposited at the vegetal hemisphere of the egg; these become incorporated into the large micromeres at fourth cleavage. When an isolated animal hemisphere is combined with isolated micromeres, then what will be the result?
#Question id: 7179
#Unit 5. Developmental Biology
Blocking BMP(BMP2, BMP4, BMP7) signaling by infecting progress zone cells with retroviruses carrying dominant negative BMP receptors. Which of the following results are found?
#Question id: 7180
#Unit 5. Developmental Biology
Development
of tetrapod limb has to function in a three dimensional coordinated system:
Proximal-distal
axis by ____a_____
Anterior-posterior
axis by ___b_____
Dorsal-ventral
axis by ______c____
Which of the following combinations are correct?