In multiple sclerosis, the myelin sheaths around the axons of the brain and spinal cord are damaged and demyelination results. How does this disease manifest at the level of the action potential?

 I) Action potentials move in the opposite direction on the axon.

 II) Action potentials move more slowly along the axon.

 III) No action potentials are transmitted.

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?