The most important regulatory control that restricts cyclins to the appropriate cell cycle stage is ubiquitin mediated, proteasome-dependent protein degradation. Which of the following statement is incorrect regarding to the degradation of protein?

#Question id: 10228

#Unit 6. System Physiology – Plant

Photorespiration and the quantum yield differ between C3 and C4 photosynthesis, with changes particularly noticeable as temperatures vary quantum yield for photosynthesis as a function of leaf temperature in C3 plants and C4 plants. Following are some statements  based on this study.

 a.) In the C4 plants the quantum yield remains constant with temperature, reflecting low rates of photorespiration

 b.) At lower temperatures the quantum yield of C3 plants is higher than that of C4 plants

c.) C3 photosynthesis is more efficient at lower temperatures

 d.) At higher temperatures the quantum yield of C3 plants is higher  than that of C4 plants

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

#Question id: 10226

#Unit 6. System Physiology – Plant

Under moderate excess light Quantum efficiency decreases , but the maximum photosynthetic rate remains unchanged and caused by the diversion of absorbed light energy toward heat dissipation—hence the decrease in quantum efficiency this term is known as

#Question id: 10223

#Unit 6. System Physiology – Plant

when plastoquinone is accumulates in the reduced state, Reduced plastoquinone accumulates when PSII is being activated more frequently than PSI. What will happen when plastoquinone becomes more oxidized?

#Question id: 10222

#Unit 6. System Physiology – Plant

Energy partitioning between two photosystem protects them from quick dessipation or quick inactivation this energy partitioning take place by a protein kinase that can phosphorylate a specific threonine residue on the surface of LHCII, what is the role of LHCII in phosphorylated and non-phosphorylated state?

a.) LHCII in phosphorylated state migrate towards the PSI in the unstacked region and delivers energy to the PSI 

b.) LHCII in nonphosphorylated state moves back to the grana and delivers energy to the PSII

c.) LHCII in phosphorylated state migrate towards the PSII in the stacked region and delivers energy to the PSI 

d.)  LHCII in nonphosphorylated state moves towards the stroma lamellae unstacked region and delivers energy to the PSII 

Which of the following combination is CORRECT?

#Question id: 10220

#Unit 6. System Physiology – Plant

Thylakoid membranes contain a protein kinase that can phosphorylate a specific threonine residue on the surface of LHCII. How the kinase is activated?

#Question id: 10219

#Unit 6. System Physiology – Plant

The PSII reaction center leads to easily  inactivation and damage by photoinhibition process while Photosystem I Is Protected from Active Oxygen Species, Why PSI protect from active oxygen species in compare to PSII