Which event during the evolution of land plants probably made the synthesis of secondary compounds most beneficial? 

TLS Online TPP Program

#Question id: 12404

#Unit 6. System Physiology – Plant

Covalent conjugation of amino acids to IAA can result in___

TLS Online TPP Program

#Question id: 12405

#Unit 6. System Physiology – Plant

Sequestration of auxin in endomembrane compartments, primarily in the__

TLS Online TPP Program

#Question id: 12406

#Unit 6. System Physiology – Plant

The β-oxidation of indole-3-butyric acid (IBA) to IAA takes place in___

TLS Online TPP Program

#Question id: 12407

#Unit 6. System Physiology – Plant

ABA is synthesized via _____A________, the biosynthetic processes  occur in_____B_____and ____C_____.

TLS Online TPP Program

#Question id: 12408

#Unit 6. System Physiology – Plant

Cleavage of the carotenoid by the enzyme NCED (9-cis-epoxycarotenoid dioxygenase) is a rate-limiting highly regulated step in ABA synthesis that produces the 15-carbon precursor molecule xanthoxin in

TLS Online TPP Program

#Question id: 12409

#Unit 6. System Physiology – Plant

The Chemical Structure of ABA Determines Its Physiological Activity, 15 carbon compound 

a) The orientation of the carboxyl group at carbon 2 determines the cis and trans isomers of ABA. Nearly all the naturally occurring ABA is in the cis form

b) S enantiomer is the natural form; commercially available synthetic  ABA is a mixture of approximately equal amounts of the S and R forms.

c) The S enantiomer is the only one that is active in fast responses to ABA, such as stomatal closure

d) In long-term responses, such as seed maturation, only R-enantiomers are active

e) In contrast to the cis and trans isomers, the S and R forms cannot be interconverted in the plant tissue

Which of the following is the correct prediction about the active form  of ABA?