#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: 19901
#Unit 12. Applied Biology
#Question id: 3879
#Unit 3. Fundamental Processes
Which of the following is not usually essential for the catalytic activity of ribozymes?
#Question id: 27122
#Unit 4. Cell Communication and Cell Signaling
#Question id: 29078
#Unit 10. Ecological Principles
A specific kind of parasitism proposes that in which cuckoos or cowbirds repeatedly check their host’s nests and destroy all eggs if their owner is not present. If the parasite egg has been removed, they destroy the host’s nest and kill or injure the nestlings, this is an example of____