The rate of polymerization of actin filaments is given by rate constant K, in which_____

a) the addition of monomers is given by kon (M^–1 sec^–1 ) 

b) the addition of monomers is given by koff  (sec^–1)

c) the loss of monomers is given koff (M^–1 sec^–1 ) 

d) the loss of monomers is given koff (sec^–1)

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#Question id: 10419

#Unit 6. System Physiology – Plant

The conversion of Pr to Pfr by red light, both phyA and phyB move from the cytosol into the nucleus in a light-dependent fashion.

a) Both have nuclear localization signal (NLS) sequences

b) PRD domain of phyB can potentially serve as an NLS, but it is apparently masked in the Pr form

c) phyA dependent on other proteins, such as FAR-RED ELONGATED HYPOCOTYL1 (FHY1) facilitating phyA’s transport it into the nucleus

d) Both phyA and phyB have PRD domain serve as an NLS and responsible for import into the nucleus only in pfr form may expose the functional NLS of the PRD domain

Which of the following factors is involved for transporting phyA and B into the nucleus?

TLS Online TPP Program

#Question id: 10420

#Unit 6. System Physiology – Plant

 A toggle model has been proposed for phytochrome interconversion, according to this model which option is correct?

TLS Online TPP Program

#Question id: 10421

#Unit 6. System Physiology – Plant

The red light-induced rotation of the D ring of the chromophore causes the hairpin to become helical, which of the following β-hairpin changes conformation after rotation?

TLS Online TPP Program

#Question id: 10422

#Unit 6. System Physiology – Plant

Arabidopsis contains five genes encoding phytochromes, PHYA–PHYE, four of the five phytochromes appear mostly light-stable in the plant and function primarily in the regulation of LFRs and of shade avoidance involving changes in the R:FR ratio.

TLS Online TPP Program

#Question id: 10423

#Unit 6. System Physiology – Plant

Which of the following responses include processes such as the promotion of lettuce seed germination, inhibition of hypocotyl elongation, and regulation of leaf movements?

TLS Online TPP Program

#Question id: 10424

#Unit 6. System Physiology – Plant

Phytochrome responses fall into three major categories based on the amount of light they require, which one is not the category of phytochrome responses;