#Question id: 11748
#Unit 6. System Physiology – Plant
In mature cells, P-protein occurs in several different forms depending on the species. Such as;
#Question id: 11802
#Unit 6. System Physiology – Plant
Damaged sieve elements are sealed off, but because of the processs that plug sieve plates pores, excuded phloem sap from wounds that sever sieve elements. Exudation of sap enhanced by the inclusion of;
#Question id: 11803
#Unit 6. System Physiology – Plant
Due to damage exudation of sap from cut petioles or stems takes place they can be collected. However, quantities of collected sap are small, and the method is technically difficult. A preferable approach for collecting exuded sap is to use an
#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