The mussel Mytilus edulis thrives in saline habitats, in both the highly salty seawater of tidal zones and the less salty estuaries. This results in two kinds of populations: one adapted to the higher salt concentrations of the tidal zone, and one adapted to the lower salt concentrations of the estuary. It has been found that the more salt-tolerant populations have high frequencies of an allele that produces an enzyme involved in maintaining osmotic equilibrium. Conversely, estuarine mussels having the same enzyme seem to be disfavoured and have a much higher death rate than mussels without the allele. Adult estuarine populations do have lower frequencies of this allele. Each spring, large numbers of larvae from  the salty habitats pour into the estuaries.

The invasion of the seawater larvae would be expected to facilitate change in the genetic structure of the estuarine population by a process called

#Question id: 10461

#Unit 6. System Physiology – Plant

Model of cry1 interactions with COP1/SPA1 in the regulation of photomorphogenesis, what will happen in the dark as well as in the light in wild type condition of cryptochrome?

a) In the dark, COP1/SPA1 acts to degrade transcription factors such as HY5, which is required for photomorphogenesis

b) In the dark, cry1 is activated by phosphorylation and forms a complex with COP1 and SPA1 via the C-terminal domain, preventing them from degrading protein HY5

c) In the light, COP1/SPA1 acts to degrade transcription factors such as HY5, which is required for photomorphogenesis

d) In the light, cry1 is activated directly by blue light and indirectly by blue light induced phosphorylation and forms a complex with COP1 and SPA1 via the C-terminal domain, preventing them from degrading protein HY5

e) In light as well as in dark both case cryptochrome perfom same function such as forming a complex with COP1/ SPA1 thereby promoting an increase in HY5 protein levels and transcription

Which of the following combinations from the above statements of cryptochrome is incorrect?

#Question id: 10460

#Unit 6. System Physiology – Plant

CCT overexpression mutant shows____

#Question id: 10459

#Unit 6. System Physiology – Plant

The role of N-terminus and the C-terminus region of the cryptochrome is given below;

a) N-terminal region is involved in the dimerization of cryptochrome and conformational changes

b) C terminus of cryptochrome forms a complex with SPA1 and COP1 that prevents them from acting, thereby preventing the degradation of HY5

c) N-terminal region of cryptochrome forms a complex with SPA1 and COP1 that prevents them from acting, thereby preventing the degradation of HY5

d) Arabidopsis plants overexpressing only the C-terminal region of cryptochrome (CCT) which resemble light-grown seedlings when grown in darkness

Which of the following combinations from the above statements is correct?

#Question id: 10457

#Unit 6. System Physiology – Plant

Cryptochromes are blue-light photoreceptors that mediate several blue-light responses, including__hypocotyl elongation, cotyledon expansion, petiole elongation, anthocyanin production and several other responses. Which of the following graph given below correct representing of blue light responses?

#Question id: 10456

#Unit 6. System Physiology – Plant

Two identical subunits of UVR8 are linked in the dimer by a network of

#Question id: 10455

#Unit 6. System Physiology – Plant

Phototropins regulate chloroplast movements via_____