#Question id: 11601
#Unit 6. System Physiology – Plant
Gibberellin is an important plant hormone that regulates
several aspects of plant growth and development. Some statements are given
below in relation to signalling
pathways:
a) The binding of gibberellin (GA) to its receptor leads to
the degradation of the DELLA repressor by the 26S proteasome
b) Gibberellin binds to the GID1 receptor and induces a
conformational change in the N-terminal domain of the receptor, allowing the
receptor to interact with the TVHYNP and DELLA domains of the DELLA repressor
c) The formation of the GID1-repressor complex promotes the
interaction between the repressor and the E3 ubiquitin ligase SCFTIR1 complex,
leading to the ubiquitination and degradation
d) The gibberellin receptor GIBBERELLIN INSENSITIVE DWARF 1
(GID1) also itself function as an F-box protein
Which one of the following is the incorrect statements about GA signalling pathway;
#Question id: 11602
#Unit 6. System Physiology – Plant
The concentration of gibberellins in plants is very low usually 1–10 parts per billion for the _____A_________ in _______B________ and up to 1 part per million of total gibberellins in ______C________.
#Question id: 11603
#Unit 6. System Physiology – Plant
Several important role promotes GA in the plant except____
#Question id: 11604
#Unit 6. System Physiology – Plant
What will be the effect of exogenous gibberellin in plant?
a) extreme stem elongation in dwarf plants
b) Increases in stem
thickness
c) decrease in leaf size
d) decreases in stem thickness
e) Increases in leaf size
f) pale green color of the leaves
#Question id: 11605
#Unit 6. System Physiology – Plant
Major uses of gibberellins applied as a spray or dip, are to manage several processes except,
#Question id: 11606
#Unit 6. System Physiology – Plant
What will be the effect light in GA biosynthesis?
a) Light basically activates the GA 3β-hydroxylase which
adds a hydroxyl group (OH) to carbon 3 of GA20 and convert GA20 to GA1
b) light-induced increase in the transcription of the gene
for GA3ox, which converts GA20 to GA1
c) light-induced increase in the transcription of the gene
for GA2ox, which converts GA20 to
GA29
d) light-induced decreases the transcription of the gene for GA3ox, which converts GA20 to GA1