PCB 3233 Immunology Exam 4 Questions With correct Answers

PCB 3233: Immunology Exam 4 Questions With correct
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Answers
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2 //Distinct //T-Cell //Lineages //- //CORRECT //ANSWERS(S)✔✔a:b //& //g:d //(α:β //& //γ:δ)



Positive //Selection //- //CORRECT //ANSWERS(S)✔✔leads //to //the //death //of //immature //T-cells
//having //receptors //that //do //not //interact //with //any //self-MHC //I //or //II //(takes //place //prior //to


//negative //selection)




Negative //Selection //- //CORRECT //ANSWERS(S)✔✔induces //death //of //those //immature //T-cells
//that //are //autoreactive //(also //happens //with //B-cells)




Majority //Lineage //Type //of //T-Cell //- //CORRECT //ANSWERS(S)✔✔a:b //(α:β //95%)



Minority //Lineage //Type //of //T-Cell //- //CORRECT //ANSWERS(S)✔✔g:d //(γ:δ //5%)



What //is //another //word //for //immature //T-cell? //- //CORRECT //ANSWERS(S)✔✔thymocyte



What //is //the //epithelial //cell //network //that //thymocytes //are //embedded //in //called? //-
CORRECT //ANSWERS(S)✔✔thymic //stroma
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What //takes //place //in //the //Thymus //Cortex? //- //CORRECT //ANSWERS(S)✔✔most //of //T-cell
//maturation //(except //negative //selection)




What //takes //place //in //the //Thymus //Medulla? //- //CORRECT //ANSWERS(S)✔✔negative //selection
//of //T-cells

,What //do //macrophages //in //the //cortex //and //medulla //do? //- //CORRECT
ANSWERS(S)✔✔remove //thymocytes //that //fail //to //mature //properly
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What //are //Hassall's //corpuscles? //- //CORRECT //ANSWERS(S)✔✔a //feature //of //the //medulla; //site
//of //cell //destruction




What //is //DiGeorge //syndrome? //- //CORRECT //ANSWERS(S)✔✔deletion //of //chromosome //22;
//thymus //fails //to //develop




Progenitor //T-Cell //- //CORRECT //ANSWERS(S)✔✔lack //the //cell //surface //glycoproteins //(have
//CD34 //surface //glycoprotein //of //stem //cells), //germline //configuration




Double //Negative //Thymocyte //- //CORRECT //ANSWERS(S)✔✔at //the //start //of //gene
//rearrangement; //no //CD4 //or //CD8




Double //Positive //Thymocyte //- //CORRECT //ANSWERS(S)✔✔after //rearrangement; //expresses
//both //CD4 //and //CD8




Single //Positive //Thymocyte //- //CORRECT //ANSWERS(S)✔✔after //positive //selection; //expresses
//CD4 //or //CD8




IL-7 //Receptor //- //CORRECT //ANSWERS(S)✔✔essential //for //binding //IL-7 //secreted //by //thymic
//stromal //cells; //helps //tell //the //cell //what //to //do //next




Notch-1 //- //CORRECT //ANSWERS(S)✔✔at //all //stages //of //maturation //in //the //thymus //signals
//are //sent //to //this //receptor //to //drive //the //T-cell //in //their //differentiation

, How //many //chances //(per //chromosome) //does //the //B-chain //have //to //rearrange //productivly?
- CORRECT //ANSWERS(S)✔✔2
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What //does //a //successful //rearrangement //of //the //B-chain //induce? //- //CORRECT
ANSWERS(S)✔✔expression //of //CD4 //and //CD8
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Allelic //Exclusion //of //B-chain //- //CORRECT //ANSWERS(S)✔✔proliferation //initiated //by //signaling
//is //repressed




What //signals //are //repressed //in //allelic //exclusion //of //the //B-chain? //- //CORRECT
ANSWERS(S)✔✔pre-TCR, //RAG-1, //RAG-2
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When //does //rearrangement //of //the //a-chain //occur? //- //CORRECT //ANSWERS(S)✔✔after //the
//double-positive //cells //stop //dividing




Will //most //developing //T-cell //be //able //to //make //a //productive //a-chain //rearrangement? //-
CORRECT //ANSWERS(S)✔✔yes
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What //happens //after //the //first //rearrangement //between //V //and //J //segments //on //the //a-chain?
- CORRECT //ANSWERS(S)✔✔d //(δ) //segment //is //deleted
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What //is //the //first //checkpoint //of //a:b //(α:β) //chain //rearrangement? //- //CORRECT
//ANSWERS(S)✔✔once //a //b-chain //is //produced //it //is //sent //to //the //ER //to //make //sure //it //can
//bind //to //the //surrogate //a-chain //(pTα)




What //is //the //second //checkpoint //of //a:b //(α:β) //chain //rearrangement? //- //CORRECT
//ANSWERS(S)✔✔once //an //a-chain //is //made //it //is //sent //to //the //ER //to //make //sure //it //can //bind
//to //the //b-chain