Test Bank for Kuby Immunology 7th Edition Judy Owen

Test Bank for Kuby Immunology 7th Edition Judy Owen 23. Which of the following is TRUE about the binding of C5b to the pathogen surface? A. C5b binds to the pathogen surface the same way C4b and C3b do. B. C5b requires C6 binding to stabilize it before it dissociates away. C. C5b, when complexed to C6 and C7, is capable of forming the MAC on any c ell membrane, pathogen or host. D. Both B and C E. All of the above Answer: D Section: The Major Pathways of Complement Activation Difficulty: 3 Hint: How C5b binds is important to, not only its normal function, but also to p otential abnormal function associated with it. 24. Which of the following is NOT an effect of C3a and C5a binding their rec eptors on leukocytes? A. Increased vascular permeability via induction of TNF-a and IL-6 secretio n B. Induction of degranulation by granulocytes C. Increased smooth muscle contraction to aid in delivering immune cells an d molecules to the site of infection D. All of the above are effects of C3a and C5a binding their receptors. E. None of the above is an effect of C3a and C5a binding their receptors. Answer: D Section: The Diverse Functions of Complement Difficulty: 3 Hint: Anaphylatoxins display more than one single activity upon their binding. 25. Which of the following regulates complement function by directly inhibit ing formation of the MAC? A. Protectin (CD59) B. Factor I C. DAF (CD55) D. C1INH E. Factor H Answer: A Section: The Diverse Functions of Complement Difficulty: 2 Hint: Not all complement regulatory factors act at the same stages in complement fixation; some act early in the process, others act later. Chapter 7 The Organization and Expression of Lymphocyte Receptor Genes 1. Which of the following BEST encapsulates the findings of the Hozumi and Tonegawa experiments? A. Every possible light chain that could be formed, in terms of receptor sp ecificity, is encoded by a separate gene within the human genome. B. Light chains are produced by means of somatic rearrangement of germ-line DNA in B cells. C. The different light-chain variable regions are produced by means of alte rnative splicing of pre-mRNA that has been transcribed from a fixed, unchanging DNA sequence. D. Different light chains, each with unique specificity, are produced via t he activity of alternative transcription factors that regulate antibody producti on at the level of transcription initiation. E. None of the above Answer: B Section: The Puzzle of Immunoglobulin Gene Structure Difficulty: 1 Hint: The mechanism of variable region formation required asking a question that went against the current of thought at the time. 2. Which of the following gene segments is NOT found in the mouse IgL loci? A. V B. J C. D D. C E. All of the above are found in the mouse IgL loci. Answer: C Section: Multigene Organization of Ig Genes Difficulty: 1 Hint: One of the variable gene segments is missing in the IgL loci. 3. At which point in the variable segments does the RAG-1/2 complex introdu ce a single-strand break into the DNA during somatic rearrangement? A. Between the coding region and the conserved heptamer B. Between the conserved heptamer and the 12-bp spacer C. Between the 23-bp spacer and the conserved nonamer D. Between the nonamer and 12-bp spacer E. None of the above Answer: A Section: The Mechanism of V(D)J Recombination Difficulty: 2 Hint: Only one cleavage point will allow for both types of joints produced durin g the rearrangement process. 4. What introduces a transient hairpin that links the two strands in the V( D)J coding regions? A. TdT B. Artemis C. RAG-1/2 D. XRCC4 with DNA ligase IV E. Ku 70 and Ku 80 Answer: C Section: The Mechanism of V(D)J Recombination Difficulty: 2 Hint: Understand what players function at which times during the course of rearr angement. 5. What binds cut DNA and retains it in protein-DNA complex? A. TdT B. Artemis C. RAG-1/2 D. XRCC4 with DNA ligase IV E. Ku 70 and Ku 80 Answer: E Section: The Mechanism of V(D)J Recombination Difficulty: 2 Hint: Understand what players function at which times during the course of rearr angement. 6. What cleaves interstrand hairpin in V(D)J coding regions? A. TdT B. Artemis C. RAG-1/2 D. XRCC4 with DNA ligase IV E. Ku 70 and Ku 80 Answer: B Section: The Mechanism of V(D)J Recombination Difficulty: 2 Hint: Understand what players function at which times during the course of rearr angement. 7. What introduces single-strand break between V(D)J coding sequence and he ptamer RSS? A. TdT B. Artemis C. RAG-1/2 D. XRCC4 with DNA ligase IV E. Ku 70 and Ku 80 Answer: C Section: The Mechanism of V(D)J Recombination Difficulty: 2 Hint: Understand what players function at which times during the course of rearr angement. 8. What introduces nucleotides in a template-independent manner to free 3? OH created upon cleavage of the interstrand hairpin? A. TdT B. Artemis C. RAG-1/2 D. XRCC4 with DNA ligase IV E. Ku 70 and Ku 80 Answer: A Section: The Mechanism of V(D)J Recombination Difficulty: 2 Hint: Understand what players function at which times during the course of rearr angement. 9. What closes the final nicks in the sugar-phosphate backbone to generate coding and signal joints? A. TdT B. Artemis C. RAG-1/2 D. XRCC4 with DNA ligase IV E. Ku 70 and Ku 80 Answer: D Section: The Mechanism of V(D)J Recombination Difficulty: 2 Hint: Understand what players function at which times during the course of rearr angement. 10. What recognizes nonamer RSS to begin lymphocyte receptor rearrangement? A. TdT B. Artemis C. RAG-1/2 D. XRCC4 with DNA ligase IV E. Ku 70 and Ku 80 Answer: C Section: The Mechanism of V(D)J Recombination Difficulty: 2 Hint: Understand what players function at which times during the course of rearr angement. 11. Which of the following is NOT a means of generating diversity in the var iable regions of the T cell receptor genes? A. Cleavage at the coding-heptamer RSS junction by RAG-1/2 B. Somatic hypermutation following activation C. Hairpin cleavage by Artemis to generate P nucleotides D. Addition of N nucleotides by TdT E. All of the above generate diversity in the variable regions of the T-cel l receptor genes.