Stomata from intact, attached leaves of Arabidopsis illuminated with blue, red, and green light in a growth chamber, increases and decreases their aperture in response to light.

 

Find the CORRECT statements from the above graph.

i) Stomatal aperture increases when the green light is turned off, and close when the green light is turned on again

ii) Stomata from the phototropin-less double mutant phot1/phot2 respond to blue light and open further when green light is turned off

iii) stomata from the zeaxanthin less mutant npq1 do not respond to blue light and least effect to opening of the stomata further when green light is turned off

iv) the npq1 mutant and phot1/phot2 double mutant response indicate that the green reversal of the blue-light response requires zeaxanthin but also phototropin

#Question id: 12193

#Unit 6. System Physiology – Plant

#Question id: 12192

#Unit 6. System Physiology – Plant

#Question id: 12191

#Unit 6. System Physiology – Plant

#Question id: 11902

#Unit 6. System Physiology – Plant

A chemiosmotic model  has been proposed  to explain Polar transport , following steps are involve in the transport of auxin polarly;

a) IAA enters the cell either passively in the undissociated form (IAAH) or by secondary active cotransport in the anionic form (IAA–)

b) The cell wall is maintained at an acidic pH by the activity of the plasma membrane H+- ATPase

c) In the cytosol, which has acidic pH, the IAAH form predominates

d) The anions exit the cell via auxin anion efflux carriers that are concentrated at the basal ends of each cell in the longitudinal pathway

Which of the following is the correct statements about the polarly transporting of auxin?

#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_________