TLS Online TPP Program

#Question id: 20330


What does the LuxR gene do?

#Unit 4. Cell Communication and Cell Signaling
  1. an repressor protein that is terminate the transcription when it is in a complex with its ligand AHL
  2. an activator protein that is only able to turn on transcription when it is in a complex with its ligand S-adenosylmethionine (SAM)
  3. an activator protein that is only able to turn on transcription when it is in a complex with its ligand AHL
  4. an repressor protein that is terminate the transcription when it is in a complex with its ligand S-adenosylmethionine (SAM)
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TLS Online TPP Program

#Question id: 14948

#Unit 6. System Physiology – Plant

Cellulose microfibrils have an ordered structure and are synthesized at the plasma membrane, given characteristics of microfibrils;
a) Each microfibril is composed of an estimated 18 parallel chains of (1,4)-linked β-D-glucose chains tightly bonded to each other to form a crystalline microfibril
b) Microfibrils have hydrophilic surfaces, populated by polar –OH groups extending from the plane of the sugar rings
c) Microfibrils have hydrophobic surfaces, populated by nonpolar C–H groups populating the sides of stacked glucose chains
 d) microfibril important for enzymatic attack by microbial cellulases, which dock onto the hydrophobic surface and remove one glucan chain at a time
Which of the following from given characteristics of microfibrils is incorrect?

TLS Online TPP Program

#Question id: 14949

#Unit 6. System Physiology – Plant

How the matrix polysaccharides differ from the cellulose?

TLS Online TPP Program

#Question id: 14950

#Unit 6. System Physiology – Plant

NMR studies of the pectin molecules not indicate that,

TLS Online TPP Program

#Question id: 14951

#Unit 6. System Physiology – Plant

Expansins belong to a large superfamily of proteins, divided into two major expansin families, α-expansins (EXPAs) and β-expansins (EXPBs), what is the function of these two?
a) EXPAs are more active on eudicot cell walls, whereas EXPBs are more active on grass cell walls
b) EXPAs are more active on grass cell walls, whereas EXPBs are more active on eudicot cell walls
c) EXPAs loosen cellulose–cellulose junctions containing xyloglucan, whereas EXPBs loosen wall complexes containing GAX
d) EXPAs loosen wall complexes containing GAX, whereas EXPBs loosen cellulose–cellulose junctions containing xyloglucan
Which combination is correct from some given above functions of expansins,?

TLS Online TPP Program

#Question id: 14952

#Unit 6. System Physiology – Plant

Some are thin areas where the primary wall is not covered by a secondary wall and are populated with plasmodesmata known as

TLS Online TPP Program

#Question id: 14953

#Unit 6. System Physiology – Plant

Which of the following is a wound-inducible glucan composed primarily of β(1,3)-linkages?