#Question id: 10435
#Unit 6. System Physiology – Plant
What happens when Pfr moves to the nucleus?
#Question id: 10436
#Unit 6. System Physiology – Plant
Both PHYA and PHYB activate the transcription of LHCB gene for its expression, there following events occur during the activation of LHCB gene such as;
a) PhyA, both form is activated Pr and Pfr by phosphorylation Pr form move into the nucleus activate the light-regulated gene expression during degradation of the HY5 by COP1
b) PhyA, Pfr form is activated by phosphorylation and move into the nucleus where it’s export the COP1 out of the nucleus, and activate the light-regulated gene expression
c) Phy B, activated phosphorylated Pfr form is move into the nucleus and binds to a dimer of the transcription factor PIF3, by inibiting PIF3 expression activate the transcription of LHCB gene by intermediate transcriptional factor MYB
d) Phy B, activated unphosphorylated Pfr form is move into the nucleus and binds to a monomer of the transcription factor PIF3, by inibiting PIF3 expression activate the transcription of MYB gene by intermediate transcriptional factor LHCB
Which of the following combination of the above statements of phytochrome forms is correct?
#Question id: 10437
#Unit 6. System Physiology – Plant
Phytochrome-mediated control of photomorphogenesis is linked to many other gene functions. The following statements are made on the mechanism of phytochrome action:
a) COP1, negative regulator of photomorphogenesis, is a component of the E3 ubiquitin ligase complex that targets photomorphogenesis-promoting proteins for degradation such as phyA
b) Light-dependent export of COP1 to the cytoplasm is a slow process, requires long exposure to light
c) The absence of COP1 in the cytosol permits the accumulation of transcriptional activators necessary for photomorphogenic development
d) The COP1–SPA1-E3 ligase complex is also responsible for the ubiquitination and proteasomal degradation of photomorphogenesis-promoting proteins, such as HY5
Which one of the following combinations is correct?
#Question id: 10438
#Unit 6. System Physiology – Plant
Which of the following are participate in the control of circadian clocks and flowering?
#Question id: 10439
#Unit 6. System Physiology – Plant
Cryptochromes are blue-light photoreceptors that mediate several blue-light responses, including___
#Question id: 10440
#Unit 6. System Physiology – Plant
cry1 mutant causes_______