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.

The genetic polymorphism found in Achillea lanulosa is most likely maintained primarily by

#Question id: 11849

#Unit 6. System Physiology – Plant

According to chemiosmotic model for polar auxin transport, auxin _____A_______is driven by the______B________ across the plasma membrane, while auxin ___C_____is driven by the_________D_________

#Question id: 11848

#Unit 6. System Physiology – Plant

Polar transport is specific for active auxins, such as

#Question id: 11847

#Unit 6. System Physiology – Plant

On the basis of isotopic labeling and metabolite identification, oxidative pathways are more likely to be involved in the controlled degradation of IAA by____

Statement-I ___IAA is oxidized without decarboxylation to OxIAA

Statement-II___ IAA-aspartate conjugate is oxidized first to the intermediate dioxindole-3-acetylaspartate, and then to OxIAA

#Question id: 11846

#Unit 6. System Physiology – Plant

In maize  orange pericarp (orp) mutant is

#Question id: 11845

#Unit 6. System Physiology – Plant

IAA Is synthesized from__

#Question id: 11844

#Unit 6. System Physiology – Plant

The following statements are made to describe the biosynthetic pathway of IAA;

a)  IPA pathway involves a deamination reaction to form IPA, followed by a decarboxylation reaction to form indole-3-acetaldehyde (IAld) and then oxidized to IAA by a specific dehydrogenase

b) IAN pathway is similar to the IPA pathway, except that the order of the deamination and decarboxylation reactions is reversed, and different enzymes are involved

c) IAM pathway  involves the two enzymes  tryptophan monooxygenase and IAM hydrolase

d) In the IAN pathway, tryptophan is first converted to indole-3-acetaldoxime and then to indole-3-acetonitrile. The enzyme that converts IAN to IAA is called nitrilase

Which of the following is the correct  statements  of about the biosynthesis of  IAA?