Meselson and Stahlʹs experiments involved growing E. coli on a medium containing 15N (heavy nitrogen) which increased the density of the bacterial DNA. Cells were then grown on a medium containing only 14N. DNA samples were obtained for analysis after one, two and three rounds of replication (generations) and centrifuged on a density gradient. The double-helical DNA forms bands in the gradient depending on its density. How many bands did Meselson and Stahl see after two generation of cells were grown on the 14N medium?

#Question id: 10216

#Unit 6. System Physiology – Plant

One of the mechanism that is thought to be involved in protecting the photosynthetic machinery against overexcitation and subsequent damage such mechanism is known as

#Question id: 10217

#Unit 6. System Physiology – Plant

Another effect that appears to be a major factor in the stability of the photosynthetic apparatus, which occurs when excess excitation arriving at the PSII reaction center leads to its inactivation and damage is known as

#Question id: 10218

#Unit 6. System Physiology – Plant

An effect that appears to be a major factor in the stability of the photosynthetic apparatus is photoinhibition, which occurs when excess excitation arriving at the PSII reaction center leads to its inactivation and damage due to

#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

#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: 10221

#Unit 6. System Physiology – Plant

plastoquinone is one of the electron carriers between PSI and PSII, accumulates in the reduced state. Reduced plastoquinone accumulates when

a.) PSI is being activated more frequently than PSII

b.) PSII is being activated more frequently than PSI  

c.) LHCII is not phophorylated

d.) LHCII is phophorylated

Which of the following state will correct?