Following statements are regarding to receptor serine kinases.

A. The two serines in each Smad3 that were phosphorylated by the RI receptor kinase bind to phosphoserine-binding sites in the MH1 domains of a Smad3 or a Smad4, forming a stable complex containing two molecules of phosphorylated Smad3 (or Smad2) and one molecule of the co-Smad (Smad4).

B. The bound importin then mediates translocation of the heteromeric R-Smad/co-Smad complex into the nucleus.

C. After importin dissociates inside the nucleus, the Smad3/Smad4 (or Smad2/Smad4) complex binds to other transcription factors to activate transcription of specific target genes.

D. Transcription of the PAI-1 gene requires formation of a complex of the transcription factor TFE3 with the R-Smad/co-Smad (Smad3/Smad4) complex and binding of all these proteins to specific sequences within the regulatory region of the PAI-1 gene.

E. Within the nucleus, R-Smads are further modified by phosphorylation of their linker domains, monoubiquitinylation of their MH1 domains, acetylation of their MH2 domains, and dephosphorylation of the C-terminal serines by nuclear phosphatases.

Which of the following combination is incorrect?

#Question id: 11532

#Unit 6. System Physiology – Plant

Which of the following are the primary sites of IAA synthesis?

#Question id: 11533

#Unit 6. System Physiology – Plant

 IAA biosynthesis is associated with__

#Question id: 11534

#Unit 6. System Physiology – Plant

Which of the following is the precursor of auxin?

#Question id: 11535

#Unit 6. System Physiology – Plant

During IPA pathway in the biosynthesis of auxin using  following enzymes except_____

#Question id: 11536

#Unit 6. System Physiology – Plant

IAA has been found to be conjugated to both high- and low-molecular-weight compounds such as,

a) Low-molecular-weight conjugated auxins include esters of IAA with glucose or myo-inositol and amide conjugates such as IAA-N-aspartate

b) High-molecular-weight IAA conjugates include IAAglucan and IAA-glycoproteins found in cereal seeds

c) High-molecular-weight conjugated auxins include esters of IAA with glucose or myo-inositol and amide conjugates such as IAA-N-aspartate

d) Low-molecular-weight IAA conjugates include IAAglucan and IAA-glycoproteins found in cereal seeds

Which of the following is the correct prediction about low-and high-molecular weight ?

#Question id: 11537

#Unit 7. System Physiology – Animal

Testosterone is an example of a chemical signal that affects the very cells that synthesize it, the neighboring cells in the testis, along with distant cells outside the gonads. Thus, testosterone is an example of ________.

 I) an autocrine signal

 II) a paracrine signal

 III) an endocrine signal