#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
#Question id: 11607
#Unit 6. System Physiology – Plant
How the active gibberellin GA1 is inactived by?
a) By hydroxylation remove
GA20 from the biosynthetic pathway by converting it to GA1
b) conversion to GA8 by a hydroxylation on carbon 2
c) By hydroxylation remove GA20 from the biosynthetic pathway by converting it to GA29
#Question id: 11608
#Unit 6. System Physiology – Plant
Which of the following growth hormone promote stem growth and were discovered in relation to the “foolish seedling disease” of rice?
#Question id: 11609
#Unit 6. System Physiology – Plant
All of gibberellins are tetracyclic diterpenoid acids, but only a few of which, have intrinsic biologically active gibberellins these are__
#Question id: 11610
#Unit 6. System Physiology – Plant
Environmental factors such as photoperiod and temperature can alter the levels of active gibberellins by affecting gene transcription for specific steps in the biosynthetic pathway such as;
a) Promotion of germination by light has been shown to be
due to increases in GA1 levels resulting from a light-induced increase in the
transcription of the gene for GA3ox, which converts GA20 to GA1
b) level of GA20-oxidase occurs in the highest amount in
shoot tips and elongating stems, is increased under long-day conditions. The fact that GA 20-oxidase is the enzyme that
converts GA53 to GA20
c) Giving cold treatment
of Thlaspiarvense and a return to high temperatures, the ent-kaurenoic
acid is converted to GA9, the most active gibberellin for stimulating the
flowering response
d) Potato plants overexpressing the GA20ox gene showed
tuberization, whereas transformation with the antisense gene for GA20ox
inhibited tuberization
Which of the following from the given above statements is correct?