Nitrogen (N) normally forms three covalent bonds with a valence of five. However, ammonium has four covalent bonds, each to a different hydrogen (H) atom (H has a valence of one). What do you predict to be the charge on ammonium?

#Question id: 11850

#Unit 6. System Physiology – Plant

The first step in polar transport is auxin influx. According to the model, auxin can enter plant cells from any direction by either of two mechanisms:

a) Passive diffusion of the protonated (IAAH) form across the phospholipid bilayer

b) Secondary active transport of the dissociated (IAA–) form via a 2H+–IAA– symporter

c) Active diffusion of the protonated (IAAH) form across the phospholipid bilayer

Find out the correct statements of about diffusion of IAA.

#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__