#Question id: 11737
#Unit 6. System Physiology – Plant
Cytokinins have been shown to have effects on many
physiological and developmental processes, including____
a)
Leaf senescence
b)
Apical dominance
c) Gametophytic
development
d) Vascular development
e)
Breaking of bud dormancy
f) Causing bud dormancy
#Question id: 11738
#Unit 6. System Physiology – Plant
The ribotide and riboside forms of trans-zeatin can be interconverted, and free trans-zeatin can be formed from the ribotide by the
#Question id: 11739
#Unit 6. System Physiology – Plant
which of the following compound is resist to cleave by cytokinin oxidase and why?
#Question id: 11807
#Unit 6. System Physiology – Plant
Given below are few statements regarding the cytokinin
signalling pathway;
a) Cytokinin inhibits the activation of a Cdc25- like
phosphatase, whose role is to remove an inhibitory phosphate group from the
Cdc2 kinase
b) Cytokinin oxidase irreversibly inactivates cytokinins,
and it could be important in regulating or limiting cytokinin effects
c) Cytokinin signal transduction pathway is completed on
multiple places such as ER, Cytosol and Nucleus
d) Elevation of endogenous cytokinin levels in transgenic
Arabidopsis results in overexpression of the KNOTTED homeobox transcription
factor homologs KNAT1 and STM—genes
Which of the following combinations from the given above statements is correct?
#Question id: 11808
#Unit 6. System Physiology – Plant
In addition to the free bases, which are the only active
forms, active cytokinin levels are decreased through;
a) Addition of sugar molecule to the 3, 7, or 9 nitrogen of
the purine ring, called glycosylation-mediated inactivation
b) cis-trans isomerisation of zeatin
c) Irreversible cleavage by cytokinin oxidases.
Which of the following is incorrect?
#Question id: 11809
#Unit 6. System Physiology – Plant
Shortly after the discovery of kinetin, it was observed that
the differentiation of cultured callus tissue derived from tobacco pith
segments into either roots or shoots depends on the ratio of auxin to cytokinin
in the culture medium. Whereas
a) high auxin:cytokinin ratios stimulated the formation of
roots
b) high auxin:cytokinin ratios stimulated the formation of
shoots
c) low auxin:cytokinin ratios led to the formation of shoots
d) low auxin:cytokinin ratios stimulated the formation of
roots
which of the following combination is correct about the ratio of auxin to cytokinin