Multiple Choice QuestionsKeeping in view the 'fluid mosaic model' for the structure of cell membrane, which one of the following statements is correct with respect to the movement of lipids and proteins from one lipid monolayer to the other (described as flip-flop moment)?
Both lipids and proteins can flip-flop
While lipids and proteins can flip -flop
While proteins can flip-flop, lipids cannot
While proteins can flip-flop, lipids cannot
B.
While lipids and proteins can flip -flop
singer and Nicolson (1972) suggested the widely accepted fluid mosaic model of biological membranes. According to this model, the plasma membrane contains a bimolecular lipid layer, both surface of which are interrupted by protein molecules. Some proteins are attached to the polar surface of the lipid (ie, called extrinsic protein) while, other (called intrinsic proteins) either partially entirely to stick but on both sides (called transmembrane proteins). The Movement of lipid molecules from one lipid monolayer to another monolayer is called flip-flop movement. Flip-flop movement is rarely found in lipid molecules whereas it remain absent in protein molecules.
The C-4 plants are photosynthetically more efficient than C-3 plants because
the CO2 compensation point is more
CO2 generated during photorespiration is trapped and recycled through PEP carboxylase
the CO2 efflux is not prevented
the CO2 efflux is not prevented
What is the vital capacity of our lungs?
Inspiratory reserve volume plus tidal volume
Total lung capacity minus expiratory reserve volume
Inspiratory reserve volume plus expiratory reserve volume
Inspiratory reserve volume plus expiratory reserve volume
In which one of the following, the male and female gametophytes don't have free -living independent existence ?
Pteris
Funaria
Polytrichum
Polytrichum
Senescence as an active development cellular process in the growth and functioning of a flowering plant is indicated in
vessel and tracheid differentiation
leaf abscission
annual plants
annual plants
Nitrogen-fixation in root nodules of Alnus is brought about by
Bradyrhizobium
Clostridium
Frankia
Frankia
What will happen if the secretion of parietal cells of gastric glands is blocked with an inhibitor?
Gastric juice will be deficient in chymosin
Gastric juice will be deficient in pepsinogen
In the absence of HCl secretion, inactive pepsinogen is not converted into the active enzyme pepsin
In the absence of HCl secretion, inactive pepsinogen is not converted into the active enzyme pepsin
Trichoderma harzianum has proved a useful microorganism for
bioremediation of contaminated soils
reclamation of wastelands
gene transfer in higher plants
gene transfer in higher plants
Which type of white blood cells are concerned with the release of histamine and the natural anticoagulant heparin?
Neutrophils
Basophils
Eosinophils
Eosinophils
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