#Question id: 11725
#Unit 6. System Physiology – Plant
Given some statements about the roles of phytochrome and
gibberellin in shade avoidance response;
A) In direct sunlight, red light predominates and the Pfr
form of phytochrome moves into the nucleus.
B) Under a plant canopy, the light is enriched in far-red
wavelengths. Phytochrome is in the inactive Pr form.
C) As PIF proteins accumulate, PIF-induced gene expression increases,
promoting stem elongation.
D) Phy causes the turnover of PIF proteins, which act as
negative regulators of
photomorphogenesis
E) In the absence of Pfr, PIFs are not degraded, the
sensitivity to gibberellin increases, causing the degradation of DELLA
repressors
F) As a result, DELLA repressors bind PIF and prevent the
transcription of PIF-regulated gene, In the absence of PIF-induced gene
expression, stem growth is limited.
Find out the correct sequence of these responses.
#Question id: 11726
#Unit 6. System Physiology – Plant
SPY acts upstream of GAI and RGA in the Gibberellin signal transduction chain, what is the role of SPY?
#Question id: 11727
#Unit 6. System Physiology – Plant
The stages of gibberellin biosynthesis takes place various
organelles and completed in various forms such as;
a) In the endoplasmic
reticulum GA12 is converted to GA53 by hydroxylation at C-13
b) In the cytosol GA12 is converted via 13-hydroxylation pathway
into GA9 and further converted into GA4 by 3-β-Hydroxylation
c) In the cytosol GA53 is converted via 13-Hydroxylation
pathway into GA20 and further converted into GA1 by 3-β-Hydroxylation
d)
Hydroxylation at C-2 then converts GA4 and GA1 to the inactive forms
GA34 and GA8, respectively
Which one of the following given combination from the above statements is true?
#Question id: 11728
#Unit 6. System Physiology – Plant
Which of the following is the precursor of Cytokinin?
#Question id: 11729
#Unit 6. System Physiology – Plant
Given some properties of cytokinin;
a) Kinetin is a naturally occurring plant growth regulator
b) it does occur as a base in the DNA of any species
c) It is a by-product of the heat-induced degradation of DNA
d) the deoxyribose sugar of adenosine is converted to a
furfuryl ring and shifted from the 9 position to the 6 position on the adenine
ring
which of the following given statements incorrect?
#Question id: 11730
#Unit 6. System Physiology – Plant
Following are some statements regarding plant hormones.
a) Auxin and Cytokinin promote cell division
b) Auxin and Ethylene can cause similar plant responses,
such as induction of flowering in pineapple and inhibition of stem elongation
c) cytokinin and ethylene signal transduction pathways are
derived from the bacterial two-component regulatory system mainly multistep
version
d) Gibberellins Are Synthesized via the terpenoid Pathway
e) GA promotes seed dormancy while ABA causes seed
germination
Which of the following from the given above combination is incorrect?