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: 11818

#Unit 6. System Physiology – Plant

Cytokinin signals to nuclear-localized response regulators  by transferring the phosphate group to an aspartate on the receiver domain of the ARR. The ARR response regulators are encoded by multigene families, They fall into two basic classes:

I) Type-A ARRs

II)Type-B ARRs

a) The products of which are made up solely of a receiver domain

b) Receiver domain also include an output domain containing DNA-binding  transcription activation sites

c) Which negatively regulate cytokinin signaling by interacting with other proteins in a manner dependent on the phosphorylation state

d) Which are activated by phosphorylation, which enables them to regulate the transcription of a set of target genes

e) Which are targeted by F-box proteins called KISS ME DEADLY (KMD) proteins negatively regulates the cytokinin response

Which of the following are the correct explanation of the given ARRs types  classes of response regulator?

#Question id: 11819

#Unit 6. System Physiology – Plant

Ethylene is a gaseous hormones which  shows typical  triple response. Following are certain statements regarding the triple response:

a) reduced stem elongation

b) increased lateral growth (swelling)

c) promote root elongation

d) exaggeration of apical hook

Which one of the following combinations is correct?

#Question id: 11820

#Unit 6. System Physiology – Plant

Which of the following is the precursor for ethylene?

#Question id: 11821

#Unit 6. System Physiology – Plant

Immediate precursor of ethylene is___

#Question id: 11822

#Unit 6. System Physiology – Plant

The rate-limiting step in the Ethylene biosynthetic pathway is____

#Question id: 11823

#Unit 6. System Physiology – Plant

_____A________the enzyme that catalyzes the conversion of AdoMet to ACC, while ___B_____ catalyzes the conversion of ACC to ethylene