TLS Online TPP Program

#Question id: 16147


 Which statement is not true for Natural killer (NK) cells?

#Unit 4. Cell Communication and Cell Signaling
  1. Natural killer (NK) cells are lymphoid cells that are closely related to B and T cells. However, they do not express antigen specific receptors and are considered part of the innate immune system.
  2. They are distinguished by the expression of a surface marker known as NK1.1, as well as the presence of cytotoxic granules. Once referred to as “large granular lymphocytes” because of their appearance under a microscope.
  3.  NK cells constitute 5% to 10% of lymphocytes in human peripheral blood. Th ey are effi cient cell killers and attack a variety of abnormal cells, including some tumor cells and some cells infected with virus.
  4. They distinguish cells that should be killed from normal cells in a very clever way: by “recognizing” the absence of MHC class II, which is expressed by almost all normal cells, but is specifically down-regulated by some tumors and in response to some viral infections.
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TLS Online TPP Program

#Question id: 10163

#Unit 6. System Physiology – Plant

Some statements regarding C2, C3, C4 and CAM plants

a.) For Sucrose synthesis after C2 C3 and C4 cycle having different procedure

b.) C4  cycle reduces occurrence of C2 which is thermodynamically very expensive and toxic by increasing the assimilation of CO2 at high temperature almost at 350 C

c.) C4 plant is generally found in near to equator  and they are more abundant than C3 plant

d.) In Dark when stomata are closed and CO2 not assimilated in the CAM plants

Which of the following statements from above combination is true?

TLS Online TPP Program

#Question id: 10164

#Unit 6. System Physiology – Plant

C4 photosynthetic carbon cycle is also known as the

TLS Online TPP Program

#Question id: 10165

#Unit 6. System Physiology – Plant

In the C4 photosynthetic carbon cycle involves uptake of CO2 in the form of HCO3-, the acceptor of the HCO3- is

TLS Online TPP Program

#Question id: 10166

#Unit 6. System Physiology – Plant

plants such as maize whose vascular tissues are surrounded by two distinctive photosynthetic cell types In this anatomical context, the transport of CO2 from the external atmosphere to the bundle sheath cells proceeds through five successive stages such as;

a.) Fixation of the HCO3 − in phosphoenolpyruvate by PEP Case in the bundle sheath cells

b.) Transport of the four-carbon acids (malate or aspartate) to mesophyll cells that surround the vascular bundles

c.) Decarboxylation of the four-carbon acids and generation of CO2 which is then reduced to carbohydrate via the Calvin–Benson cycle

d.) Transport of the three-carbon backbone (pyruvate or alanine) formed by the decarboxylation step back to the mesophyll cells

e.) Regeneration of phosphoenolpyruvate, the HCO3 – acceptor

Which of the following stages are FALSE?

TLS Online TPP Program

#Question id: 10167

#Unit 6. System Physiology – Plant

Mechanisms of C4 acid transported mesophyll → bundle sheath for decarboxylation, which of the following CORRECT combination of decarboxylation process?

a.) NADP–malic enzyme (NADP–ME)→ transport Malate from mesophyll to bundle sheath

b.) NAD–malic enzyme (NAD–ME)→ transport Aspartate from mesophyll to bundle sheath

c.) PEP carboxykinase (PEPCK)→ transport Aspartate from mesophyll to bundle sheath

d.) PEP carboxylase (PEPCase)→ transport Malate from mesophyll to bundle sheath

TLS Online TPP Program

#Question id: 10168

#Unit 6. System Physiology – Plant

Mesophyll cells of NADP–ME type C4 photosynthesis use four transport steps across the chloroplast envelope to fix one molecule of atmospheric CO2 

a.) import of cytosolic pyruvate through unknown transporter    

b.) import of cytosolic oxaloacetate through dicarboxylate transporter

c.) Import of stromal phosphoenolpyruvate through unknown transporter

d.) export of stromal malate through dicarboxylate transportere.) export of stromal phosphoenolpyruvate through phosphoenolpyruvate phosphate translocator

f.) export of cytosolic oxaloacetate through dicarboxylate transporter         

Find the correct four transporter from the given statements