Phloem loading in the apoplastic pathway thought to mediate the transport of sucrose from the apoplast into the sieve element– companion cell complex. Which of the following  are involved in such sucrose transporting by apoplast?

a) Sucrose is at a higher concentration in the sieve element–companion cell complex indicates that sucrose is actively transported against its chemical-potential gradient

b) Sugars transport from the apoplast into the sieve elements and companion cells energy driven process

c) Phloem loading in the apoplastic pathway involves a sucrose–H+ symporter

d) the route of phloem loading is−mesophyll cells→ bundle sheath cells→ phloem parenchyma cell→ ordinary companion cell→ sieve elements

Which of the following is incorrect?

TLS Online TPP Program

#Question id: 15530

#Unit 4. Cell Communication and Cell Signaling

The activity of already differentiated effector and memory T cells is maintained by a receptor which are generally expressed on the memory and effector T cells. 

TLS Online TPP Program

#Question id: 15529

#Unit 4. Cell Communication and Cell Signaling

When does the T-cell anergy occur?

TLS Online TPP Program

#Question id: 15528

#Unit 4. Cell Communication and Cell Signaling

The B7 family of protein interact  with distinct receptor present on the T-cells, 

TLS Online TPP Program

#Question id: 15527

#Unit 4. Cell Communication and Cell Signaling

CD4 and CD8 T cells leave the thymus and enter the circulation as resting cells in which stage of the cell cycle?

TLS Online TPP Program

#Question id: 15526

#Unit 4. Cell Communication and Cell Signaling

If a thymocyte randomly generated a TCR with an affinity for MHC Class I, the TCR and CD8 would bind MHC Class I together, and generate a signal that specifically initiated a program that is 

a) silenced CD8 expression

b) silenced CD4 expression

c) induced expression of genes specific for helper T-cell lineage function

d) induced expression of genes specific for cytotoxic T-cell lineage function

TLS Online TPP Program

#Question id: 15525

#Unit 4. Cell Communication and Cell Signaling

In the instructive model, TCR/CD4 and TCR/CD8 coengagement generates unique signals, if a thymocyte randomly generated a TCR with an affinity for MHC Class I. which thymocyte would bind with MHC class I?