The herbaceous plant Achillea lanulosa is widespread in the Northern Hemisphere. Phenotypic variation in the species has been extensively studied along an altitudinal gradient from sea level to over 3,000 meters. In California there is conspicuous variation in  height; alpine plants are only several centimeters tall  while  those in  the San Joaquin Valley may reach a height of 1.8 meters. Adaptation to different local environments also results in variation in physiological processes such as photosynthetic rate, resistance to cold, and the timing of dormancy.

Which of the following methods would be best to determine whether the phenotypic variation in Achillea lanulosa is due to genotypic variation?

TLS Online TPP Program

#Question id: 12530

#Unit 6. System Physiology – Plant

Some given hormones is also called a ubiquitous hormone?

a) Ethylene

b) Gibberellin

c) Abscisic acid

d) Brassinosteroids

TLS Online TPP Program

#Question id: 12519

#Unit 6. System Physiology – Plant

Some given  statements about biosynthesis of Abscisic acid ;

a) ABA is synthesized in almost all cells that contain chloroplasts or amyloplasts

b) ABA is a 15-carbon terpenoid, or sesquiterpenoid, which is synthesized in plants by an indirect pathway via 40-carbon carotenoid intermediates

c) Cleavage of the carotenoid by the enzyme NCED (9-cis-epoxycarotenoid dioxygenase) is a rate-limiting

d) Oxidation by ABA-8′-hydroxylases lead to ABA inactivation, ABA can also be inactivated by conjugation, but this is irreversible. Both types of inactivation are also tightly regulated.

Which of the following  combination from the above statements  is correct?

TLS Online TPP Program

#Question id: 12516

#Unit 6. System Physiology – Plant

ABA Is Synthesized from a Carotenoid Intermediate is takes place in___

TLS Online TPP Program

#Question id: 12410

#Unit 6. System Physiology – Plant

Precursor of the ABA is___

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?

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_____.