#Question id: 7242
#Unit 5. Developmental Biology
The
cells of posterior marginal zone act as
the equivalent of the amphibian Nieuwkoop center because:
A.
once the PMZ has formed, it controls the other regions of the margin.
B.
Cells of PMZ initiate other regions of the margin from forming their own
primitive streaks.
C.
the entire marginal zone produces Wnt8c (capable of inducing the accumulation
of -catenin) and secrete Vg1, a member of the TGF-family.
D.
The PMZ cells secretes nodal protein and Nodal activity is needed to initiate
the primitive streak.
E.
When placed in the anterior region of the marginal zone, a graft of PMZ tissue
(posterior to and including Koller’s sickle) is able to induce wnt signaling.
Which of the following option is correct?
#Question id: 29527
#Unit 6. System Physiology – Plant
Which of the following mediates the defense responses against insect herbivory in Arabidopsis
#Question id: 166
#Unit 1. Molecules and their Interaction Relevant to Biology
For amino acids with neutral R groups, at any pH below the pI of the amino acid, the population of amino acids in solution will have:
#Question id: 4618
#Unit 11. Evolution and Behavior
Which of the following observations helped Darwin shape his concept of descent with modification?
#Question id: 7271
#Unit 5. Developmental Biology
In drosophila, Head formation required higher Bicoid concentrations than thorax formation, because