Immunology Exam Iii

Front 1

What signals the recombination process that rearranges the heavy and light chain genes V-(D)-J?
(a) Splicing
(b) RSS
(c) Mutations
(d) V(D)J Recombindase

Back 1

(b) RSS (recombination signal sequence)

Front 2

What determines, or helos ensure, proper segment order joining of gene segments? Ex, V-J
(a) Nothing, randomly inserted
(b) RAG1/RAG2
(c) V(D)J recombinase
(d) one-turn/two-turn joining rule

Back 2

(d) one-turn/two-turn joining rule

Front 3

Which assay discussed in lecture is used to assess the amount of cell death?
(a) Bromide release
(b) Chromium release
(c) Titanium release
(d) Lysosome
(e) None of the above

Back 3

(b) Chromium release assay

Front 4

N-addition occurs in the _________ and is mediated by ______.
(a) light chains; Artemis
(b) heavy chains; activation-induced cytidine deaminase (AID)
(c) heavy chains; terminal deoxynucleotidyl transferase (TdT)
(d) light chains; binding protein (BiP)

Back 4

(c) Heavy chain; terminal deoxynucleotidyl transferase (TdT)

Front 5

C3bBb has a limited half-life. What binds to C3bBb to stabilize it?
(a) Factor B
(b) Factor I
(c) Homologous restriction factor (HRF)
(d) Properdin

Back 5

(d) Properdin

Front 6

Complement is activate by?
(a) Innate
(b) Adaptive
(c) A & B
(d) None of the above

Back 6

(c) Both Innate and Adaptive

Front 7

Binding of ______ stabilizes C3 convertase in the alternative pathway.
(a) Lectin
(b) Properdin
(c) Plectin
(d) Luminase

Back 7

(b) Properdin

Front 8

Complement does not directly mediate which of the following?
(a) Inflammation
(b) Opsonization
(c) MAC
(d) Antigen presentation

Back 8

(d) Antigen presentation

Front 9

The Decay-accelerating factor binds and cleaves which of the following complex?
(a) C4b
(b) C4b2a
(c) C4b2a3b
(d) C5b67

Back 9

(b) C4b2a

Front 10

In the classical pathway, which molecules are needed for activation?
(a) Calcium
(b) Magnesium
(c) Both
(d) Neither

Back 10

(c) Both Calcium and Magnesium

Front 11

Which of the following is NOT true of Class II MHC molecules?
(a) Contain alpha and beta chains
(b) Peptide binding cleft is open at both sides
(c) Contains B2 microglobulin molecule
(d) contains cytoplasmic tail
(e) bound peptide is 13-18 amino acids long.

Back 11

(c) Contains B2 microglobulin molecule

Front 12

Which of the following complement molecules is not necessary for all three discussed complement pathways?
(a) C3
(b) C4
(c) C5
(d) C6

Back 12

(b) C4, not necessary in alternative pathway

Front 13

Which of the following are types of Ig gene modifications: I. VDJ Recombination II. Somatic Hypermutation III. RAG1/RAG2 IV. Class-Switching
(a) I & II
(b) I & IV
(c) I, II, & IV
(d) II, III, IV
(e) All of the above

Back 13

(c) VDJ recombination, Somatic Hypermutation, and class-switching

Front 14

Correctly order the initial steps of the alternative pathway:
I: Diffusion of Ba
II: Cleavage of Factor B into Ba and Bb by Factor D
III: Spontaneous generation of C3b
IV: Cleavage of C3
V: Binding of Factor B stabilized by Mg+

Back 14

III: Spontaneous generation of C3b
V: Binding of Factor B stabilized by Mg+
II: Cleavage of Factor B into Ba and Bb by Factor D
I: Diffusion of Ba
IV: Cleavage Cleavage of C3

Front 15

What is the only human C(heavy) segment that does not have an upstream switch region?
(a) gamma 1
(b) gamma 2
(c) epsilon
(d) delta
(e) alpha

Back 15

(d) delta

Front 16

Which is not a soluble protein of the classical pathway of complement activation?
(a) C1 inhibitor
(b) C4b-binding protein
(c) Factor I
(d) S protein
(e) All of the above

Back 16

(e) All of the above

Front 17

Which of the following gene rearrangement orders account for allelic exclusion?
(a) k -> lambda -> heavy
(b) heavy -> k -> lambda
(c) heavy -> lambda -> k
(d) k -> heavy -> lambda

Back 17

(b) heavy -> kappa -> lambda

Front 18

Generation of antibody response is associated with which of the following factors?
(a) specificity
(b) affinity/avidity
(c) half-life of antibody
(d) production rate
(e) all of the above

Back 18

(e) all of the above

Front 19

Which theories were eventually combined to explain antibody diversity?
I. Germ-line, II. one gene-one polypeptide, III. Selective, IV. somatic-variation

Back 19

I & IV) Germ-line theory and somatic-variation theory,

Front 20

What is the extended notation for C5 convertase in the alternative pathway?
(a)C4b2a
(b) C3bBb3b
(c) C4b2a3b
(d) C5a67

Back 20

(b) C3bBb3b

Front 21

A male and female giant panda are mated in captivity. The male panda has a haplotype b/k. The female panda has a haplotype a/d. The female gives birth to fraternal twins. Without testing the haplotypes of the twin pandas, which of the following statements is correct?

A. The twin pandas can donate an organ to their mother without worry of tissue rejection due to haplotype mismatch.

B. The twin pandas can donate an organ to their father without worry of tissue rejection due to haplotype mismatch.

C. The twin pandas can donate an organ to each other without fear of tissue rejection due to haplotype mismatch.

D. All of the above are false.

Back 21

(d) All of the above are false.

Front 22

Which of the following is NOT a domain of MHC1?
(a) alpha1
(b) alpha2
(c) alpha3
(d) beta1

Back 22

(d) beta1

Front 23

Which of the following is not a location of a one or two turn recombination signal sequence (RSS)?
(a) 3' of V
(b) 3' of D
(c) 5' of D
(d) 5' of C
(e) 5' of J

Back 23

(d) 5' of C

Front 24

Which of these is least likely to be a method of presentation of Ag by MHC?
(a) Endogenous Ag presented by MHC-I
(b) Endogenous Ag presented by MHC-II
(c) Exogenous Ag presented by MHC-II
(d) Exogenous Ag presented by MHC-I

Back 24

(b) Endogenous Ag presented by MHC-II

Front 25

Which of the following pairs are incorrectly matched?
(a) CD59 --> MIRL
(b) CD55 --> DAF
(c) MAC --> Lysis
(d) C3A --> anaphylatoxin
(e) C5 --> RCA protein

Back 25

(e) C5 --> RCA protein is false

Front 26

True of False: MASP-1 and MASP-2 are structurally similar to C1r and C1s.

Back 26

True

Front 27

MHC diversity is due to which of the following:
(a) gene rearrangement
(b) somatic mutation
(c) post-translation modification
(d) polymorphism

Back 27

(d) polymorphism

Front 28

Which complement pathway needs antigen-antibody complex for initiation?
(a) Classical
(b) Alternative
(c) Lectin
(d) All of the Above

Back 28

(a) Classical

Front 29

C3 convertases are dissociated by all of the following EXCEPT:
(a) C4b-binding protein (C4bBP)
(b) Complement receptor type 1 (CR1)
(c) Factor I
(d) Delay-accelerating factor (DAF)

Back 29

(c) Factor I does not dissociate C3 convertases

Front 30

True of False: Like macrophages and dendritic cells, most APCs are phagocytic and internalize antigens primarily through phagocytosis.

Back 30

False. Macrophages and dendritic cells internalize by both phagocytosis and endocytosis, wheras most APCs are not phagocytic, or are poorly phagocytic, and therefore internalize exogenous antigen by exocytosis. B cells, for example, internalize antigen by receptor-mediated endocytosis using antigen-specific membrane as the receptor.

Front 31

A new peptide that scientists want to isolate is made up of 15 amino acids. In the central core, it has an internal conserved sequence motif but lacks conserved anchor residues. It has a proline residue at position 2 and another cluster of prolines at the C-terminal end. What might scientists find this protein attached to?
(a) CD4
(b) TCR
(c) MHC-I
(d) MHC-II

Back 31

(d) MHC-II

Front 32

Where, in the endocytic pathway, do MHCII molecules bind to peptide fragments?
(a) endosomal compartments
(b) rough ER
(c) golgi aparratus
(d) plasma membrane

Back 32

(a) endosomal compartments

MHCII and invarient chains leave the golgi and are degraded into MHCII and CLIP in lysosomes. Exogenous antigen fuses, and that is where CLIP-peptide exchange occurs.

Front 33

The lectin and alternative complement pathways are different from the classical pathway in that they:
(a) are activated in the presence of specific antibodies
(b) are activated in the absence of specific antibodies
(c) lead to the creation of C5b
(d) lead to the formation of MAC

Back 33

(b) are activated in the absense of specific antibodies

Front 34

Which of the following lists, in order from 5' to 3', the genes contained ina rearranged kappa light chain?

a) leader exon, promotor region, intron, joined VJ segment, second intron, constant region, stop sequence

b) promotor region, leader exon, joined VJ segment, intron, constant region, second intron, stop sequence

c) promotor region, leader exon, intron, joined VJ segment, second intron, constant region, stop sequence

d) promotor region, intron, leader exon, second intron, joined VJ segment, constant region, stop sequence

e) leader exon, intron, promotor region, joined VJ segment, second intron, constant region, stop sequence

Back 34

(c) 5' promotor, leader, intron, VJ, intron, C, STOP 3'

Front 35

Which of the following correctly outlines the process of Kappa light chain gene rearrangement and RNA processing events requires to generate a K light chain protein?

6) Cleavage of leader sequence from nascent polypeptide

5) Translation of light chain mRNA

4) Transcription of rearranged light chain sequence by RNA polymerase

2) Functional V genes combine with a functional J-C gene combination

1) RNA processing enzymes remove introns and polyadenylation of 3' end occurs

3) Light chain protein is pulled into the rough ER lumen

Back 35

2) Functional V genes combine with J-C genes
4) Transcription of rearranged light chain sequence by RNA pol
1) RNA processing enzymes remove introns and polyadenylation occurs
5) Translation of light chain mRNA
3) Light chain protien is pulled into the rough ER lumen
6) Cleavage of leader sequence from nascent polypeptide.

Front 36

Which of the following gene segments are not located in the labmda light chain?
(a) V
(b) D
(c) J
(d) C

Back 36

(b) D, diversity region

Front 37

How many coding regions does a functional lambda variable region gene have?
(a) 0
(b) 1
(c) 2
(d) 3

Back 37

(c) 2; a 5'V segment and a 3' J segment

Front 38

Which of the following statements is false?

A) In birds, mice, rabbits, and sheep most of B cell development occurs in GALT

B) Isotype switching consists of switch sequences, switch recombinase, AID, and switch factors

C) Rag genes are silenced in proliferating cells

D) N nucleotide addition occurs only in heavy chains

E) B cells, like all somatic cells, are diploid. This means that allelic exclusion occurs so that only one heavy and one light gene are expressed, each from only one chromosome.

Back 38

A) In birds, mice, rabbits, and sheep most of B cell development occurs in GALT

Front 39

Somatic hypermutation in humans and mice is different from templated somatic mutation in chickens, cattle, and sheep in that:
A. In humans/mice it is required in the process of making functional B-cells.

B. In cattle, sheep, and chickens, the pseudogenes are involved in giving the B-cells a higher affinity for their already specified antigen.

C. The two processes occur in different organs completely.

D. More than one of the above are correct statements.

Back 39

(c) The two processes occur in different organs.

Front 40

MAC consists of C5b through C9 -- what triggers the initial exposure of the hydrophobic regions of the cell?
(a) C5b
(b) C7 binding to C5b6
(c) C6 to C5b
(d) C8 to C5b67

Back 40

(b) C7 binding to C5b6

Front 41

Which of the following regulators of complement is used in the alternative pathway, but NOT in the classical or lectin pathway?
(a) C1 inhibitor
(b) C4bBP
(c) Factor I
(d) Factor H
(e) S Protein
(f) Homologous Restriction Factor

Back 41

(d) Factor H competitively inhibits Factor B from binding to C3b, preventing formation of C3 Convertade.

Factor I cleaves Factor H/C3b complex in both alternative and classical.

Front 42

In terms of the complement cascade, deficiency of which of the following regulatory proteins would result in disruption of ALL three complement pathways?
(a) CRT1
(b) Factor H
(C) Factor B
(d) C4bBP

Back 42

(a) CRT1

Factor B is not an inhibitor; Factor H affects only alternative; C4bBP affects only classical and lectin

Front 43

Which of the following regulator proteins block the formation of C3 Convertase by binding to C4b or C3b in the complement cascade?
I. Factor H
II. C4bBP
III. Decay Accelerating Factor
IV. Membrane-Cofactor Protein (MCP)

Back 43

I, II, & IV) Factor H, C4bBP, and MCP

DAF accelerates dissociation of C4b2a and C3bBb

Front 44

What are the two exons for the hydrophobic transmemrane segment of a membrane-bound antibody?
(a) RAG1 & RAG2
(b) M1 & M2
(c) Ku70 & Ku80
(d) HLA-A & HLA-B

Back 44

(b) M1 and M2

Front 45

Which of the following complexes are analogous between the classical and alternative pathways?
I. C3bBb3b and C4b2a3b
II. C1s and Factor H
III. C3bBb and C4b2a
IV. C3bv3b and C4b2a

Back 45

I. C3bBb3b and C4b2a3b (C5 convertase)

III. C3bBb and C4b2a (C3 convertase)

Front 46

Viruses have developed a number of different strategies for evasion of complement activity. Which of the following are those strategies?
I. interference with the binding of complement to antibody-antigen complexes
II. Mimicry of mammalian complement regulators.
III. incorporation of cellular complement regulators
IV. They ONLY act as a cofactor for inhibitory factor I

Back 46

I. interference with the binding of complement to antibody-antigen complexes
II. Mimicry of mammalian complement regulators.
III. incorporation of cellular complement regulators

Front 47

T cells are activated by the interaction between ______ and _______.

Back 47

Peptide antigen and an MHC molecule.

Front 48

Which of the following is NOT true of ALL three complement activation pathways?
(a) Generate C3 and C5 convertase
(b) Initiated by C1
(c) Final steps are identical
(d) MAC is formed.

Back 48

(b) Initiated by C1 is false, that is only the classical pathway. Alternative w/ PAMPs, and Lectin with MBL.

Front 49

Which protein binds soluble C5b67 and prevents its insertion into the cell membrane?
(a) Factor I
(b) S protein
(c) C1 Inh
(d) C4b-binding protein

Back 49

(b) S protein

Front 50

Which of the following is true regarding skin transplantation between inbred mouse strains?
(a) b/k progeny can accept graft from b/b parent
(b) b/b parent can accept graft from b/k progeny
(c) k/k parent can accept graft from b/k progeny
(d) b/b parent can accept graft from k/k parent

Back 50

(a) b/k parent can accept from b/b parent.

Because the b/k mouse expresses MHC proteins of both parental strains on its cells, it is histocompatible with both strains and able to accept grafts from either parental strain.

Front 51

True or False: The initiation of the classical pathway is antibody dependent, while the alternative and lectin pathways are antibody dependent.

Back 51

False. The classical pathway is antibody DEPENDENT, while alternative and lectin and antibody INDEPENDENT.

Front 52

True or False: The complement system plays a role in the opsonization of bacteria, activation of inflammation, clearance of imune complexes, as well as cell lysis.

Back 52

True. Remember that main function, however, is lysis.

Front 53

Which regulatory protein affects the alternative pathway only?
(a) C1 inh
(b) C4bBP
(c) Factor H
(d) S protein

Back 53

(c) Factor H alternative only

Front 54

During antibody recombination the RSS region next to the V gene has 23 base pairs between the palindromic heptamer and the nonamer. Which of these will it likely recombine with?
(a) one turn V
(b) two turn V
(c) one turn J
(d) two turn J

Back 54

(c) one turn J. Remember one-turn/two-turn rule.

Front 55

Which of the following is false?
(a) All nucleated cells express MHC I at the same level.
(b) Proff. APCs express MHC II.
(c) MHC II can be expressed in cells other than proff APCs.
(d) MHC I accomodates peptides of 8-11 residues.
(e) MHC II accomodates peptides of 10-30 residues or more.

Back 55

(a) All nucleated cells express MHC I at the same level. False.

Front 56

A mutation in the C4 protein of the complement cascade would affect:
I. Classical
II. Lectin
III. Alternative

Back 56

I & II) Classical and Lectin

Front 57

Which complement protein has 10-16 molecules recruited to form a pore in the membrane, creating leakage of cell components, disruption of the proton gradient, and entry of enzymes?
(a) C3
(b) C5
(c) C4
(d) C9

Back 57

(d) C9 forms the completed MAC pore

Front 58

Of the following, which accurately represents the gene sequence found in heavy chain DNA?
(a) VDJC
(b) VJDC
(c) VJD
(d) VCJD
(e) CDCJ

Back 58

(a) VDJC

Front 59

True or False: Muscel cells, liver hepatocyes, neural cells, and fibroblasts express very high levels of MHC I.

Back 59

False

Front 60

Complement component C3c mediates which of the following?
(a) lysis
(b) aggregation of platelets
(c) opsonization
(d) release of neutrophils
(e) both a and c

Back 60

(d) release of neutrophils from bone marrow

Front 61

What is the function of C1 Inh in regulating the classical complement pathway?
(a) Causes C1r2s2 to dissociate from C1q
(b) Blocks formation of C3 convertase by blocking C4b
(c) Binds soluble C5b67 and prevents its insertion into the cell membrane
(d) Binds to C5b678 on autologous cells, blocking binding of C9

Back 61

(a) Causes C1r2s2 to dissociate from C1q

Front 62

Which of the following is FALSE regarding MHC II molecules?
(a) Native proteins must be processed prior to binding
(b) Binds peptides 13-20 aa in length
(c) Presents exogenously derived pepties to Th cells
(d) Consists of non-MHC encoded Beta2-microblobulin subunit

Back 62

(d) Consists of non-MHC encoded Beta2-microblobulin subunit

Front 63

Which pathway is more closely associated with innate over adaptive immunity?
(a) Lectin
(b) Classical
(c) Alternative
(d) Two of the above

Back 63

(d) Lectin and Alternative

Front 64

What is the size of the alpha-chain in MHC-I molecules?
(a) 12 kDa
(b) 45 kDa
(c) 28 kDa
(d) 33 kDa

Back 64

(b) 45 kDa

Front 65

What method was used to determine that processed antigens and self-peptides had bound to the alpha domains in the cleft formed in MHC-I molecules?

Back 65

x-ray crystallography

Front 66

Human cells are able to avoid activation of the lectin pathway by:
A. Having mannose on our cell membranes covered by sialic acid

B. MBL is unable to bind to human cells because they don't have mannose on them

C. Our cells do activate the lectin pathway, but it is shut down by regulatory components before the amplification step can occur.

D. Mannose on our cells is altered and disguised when it is processed in the ER before being exposed on the cell membrane.

E. After MBL binds our cells' mannose, it is cleaved by Factor I

Back 66

(a) Having mannose on our cell membranes covered by sialic acid.

Front 67

A deficiency in which of the following is specifically associated with a rise in hereditary angioedema?
(a) C4
(b) C1 inhibitor
(c) Factor D
(d) Properdin
(e) MBL

Back 67

(b) C1 inhibitor

Front 68

Which of the following si responsible for acting as a complement inhibitor by preventing the polymerization of C9 and consequently inhibiting MAC formation?
(a) DAF
(b) S protein
(c) HRF
(d) C1 Inh

Back 68

(c) HRF

Front 69

Which of these is NOT something both MHC I and II have in common?
(a) Don't discriminate between self and non-self
(b) consist of extracellular peptide binding cleft, Ig-like domain, transmembrane domain, and cytoplasmic region
(c) Consist of alpha-helices and a floor of 8 stranded beta sheets
(d) Native proteins have to be processed prior to binding
(e) Binds peptides 13-20 amino acids in length.

Back 69

(e) Binds peptides 13-20 amino acids in length (only MHC I)

Front 70

Which of the following would inhibit minding of OR to C3b?
I. C1
II. MCP
III. Factor I
IV. CR1
V, Factor H

Back 70

II. MCP
IV. CR1
V. Factor H
All inhibit C3b binding.

Front 71

The pioneering Tonegawa and Hozumi experiment of 1976 established all of the following EXCEPT:
A) During the maturation of B-lymphocytes, V and C genes undergo rearrangement.
B) A powerful method of analyzing immunoglobulin genes called Southern-blot analysis.
C) The intervening DNA sequence between V and C genes is eliminated during differentiation.
D) Restriction endonuclease sites existing in DNA play a role in bringing V and C genes closer together.
E) All of the above were established by this experiment.

Back 71

B) A powerful method of analyzing immunoglobulin genes called Southern-blot analysis.

Front 72

True or False: The lectin complement pathway activation does not target human cells as they normally have a sialic acid residue covering the sugar groups recognized by MBL.

Back 72

True.

Front 73

Which of the following is a correct match between the human chromosome number and its corresponding product?
(a) 2, lambda chain
(b) 14, IgM heavy chain
(c) 22, kappa chain
(d) 48, D gene segment of heavy chain

Back 73

(b) 14, IgM heavy chain

Front 74

Which of the following are produced from B-cells that have matured in the peripheral lymphoid organs?
(a) IgG
(b) IgA
(c) IgE
(d) All of the above

Back 74

(d) IgG, IgA, and IgE

Front 75

All of the following are properties of the MHC except:
A. Most polymorphic genes in genome and also polygenic on individual level.

B. Each person has 2 haplotypes (set of MHC alleles on each chromosome) - one from mother and one from father.

C. Syngeneic inbred mice have a single haplotype, where allogeneic may have differing haplotypes.

D. MHC alleles are independently expressed.

Back 75

(d) MHC alleles are independently expressed

Front 76

When does somatic hypermutation occur during B cell growth?
I. Bone marrow
II. When it's a progenitor
III. In the peripheral lymphoid organ
IV. After it's mature.

Back 76

II. when it's a progenitor
III. In the peripheral lymphoid organ.

Somatic hypermutation occurs after the B cell has obtained functional maturity and after it has left the bone marrow.

Front 77

Which involves or is involved with allelic exclusion?
(a) ensures multiple antigen specificity for B cells
(b) ensures single antigen specificity for B cells
(c) ensures a B cell expressed heavy-chain genes from one chromosome
(d) ensures a B cell expresses light chain genes from both chromosomes
(e) B and C
(f) all of the above

Back 77

(e) B and C

One antigen specificity from one chromosome

Front 78

Which of the following is least correct:
A. It is thought that once a successful VDJ and VL occurs, recombination machinery is turned off.

B. Class (Isotype) switching introduces changes that affect antigen binding properties

C. Activation-induced cytidine deaminase is important in the mediation of class switching and somatic hypermutation.

D. There are far more V germ-line segments than D or J segments in heavy and light chains

Back 78

B is False. Class switching affects effector function. It allows VDJ to be associated with different constant regions

Front 79

The smaller fragments resulting from complement cleavage, C3a and C5a, are observed to do which of the following:

a) protect cells from non-specific complement-mediated lysis

b) prevent assembly of poly-C9 and its insertion into the plasma membrane

c) bind to receptors on mast cells and blood basophils and induce degranulation with release of histamine

d) recognize and bind to specific carbohydrate targets

Back 79

c) bind to receptors on mast cells and blood basophils and induce degranulation with release of histamine

Front 80

Which of the following is least correct concerning somatic hypermutation?
A. It increases affinity maturation
B. It changes specificity
C. It increases diversity
D. It is a source of variation at CDR1, CDR2, and CDR3
E. All are correct

Back 80

B
(Note: Somatic hypermutation INCREASES specificity, it does not change it.)

Front 81

Which mechanism below contributes to increasing antibody diversity in the VJ or VDJ segments that occur through nucleotide substitutions. This process also influences the overall affinity for antigen in the CDRs of the heavy and light variable sequences in mature B cells. The process also thus increase the antigen affinity of the B cell population.

1) N-addition

2) P-addition

3) Junctional flexibility

4) Somatic hypermutation

5) Combinatorial V(D)J joining

Back 81

(4) Somatic Hypermutation

Front 82

1) What is the correct order of genes for light chain rearrangement (5'-->3')?

A. Promoter, Leader sequence, VJ segment, Intron, C region

B. Leader sequence, Promoter, Intron, VJ gene segment, Intron

C. Promoter, Leader sequence, C region, Intron, VJ gene segment

D. Promoter, Leader sequence, Intron, VJ segment, Intron, C region

E. Leader sequence, Promoter, Intron, VJ segment, C region

Back 82

(d) Promoter, Leader, Intron, VJ, Intron, C, STOP

Front 83

2) Which answer is FALSE regarding heavy chain rearrangement?

A. Require 2 separate rearrangements.

B. VD segment joins to the J to form VDJ segment.

C. Primary RNA transcript is transcribed including introns and Cµ and C∂.

D. Mature B cells express both IgM and IgD on their surface.

E. None of the above.

Back 83

B. The D first joins to the J to form DJ segment. Then the DJ segment joins to the V to form VDJ segment.

Front 84

True or False: Vk gene segments sometimes join to C-lamda gene segments.

Back 84

False:

Vk gene segments and Cl are located on separate chromosomes and cannot be brought together during gene rearrangement.

Front 85

On the heavy chain, the D region codes for the 95th-97th amino acids, which make up the region known as the ______.

(a) Lambda chain Variable region

(b) Complementarity determining region 3

(c) Heavy-Chain recombination region

(d) Leader sequence

Back 85

(b) CDR3 region. This region confers specificity to the antibody.

Front 86

An enveloped virus contains a surface protein that mimics the activity of CD55 also known as DAF. What step in the alternative complement pathway does the virus directly disrupt?
A. C9 polymerization
B. Spontaneous hydrolysis of C3
C. Amplified C3b generation
D. Binding of C5b to antigenic surface

Back 86

(c) Amplification of C3b event

Front 87

Which of the following does NOT contribute to Ig gene diversity?
A. N-region nucleotides
B. junctional flexibility
C. somatic hypermutation
D. C-region nucleotides
E. P-region nucleotides

Back 87

(d) C-region nucleotide addition

Front 88

Which of the following regulates C3b and C4b by cleaving and inactivating these components of the complement cascade?
A. Factor B
B. Factor D
C. Factor I
D. Factor H
E. none of the above

Back 88

(c) Factor I

Front 89

Which of the following is NOT involved in recombination of immunoglobulin heavy-chain genes?
1) Double-strand break repair enzymes
2) RAG-1
3) RAG-2
4) Deoxynucleotidyl transferase
5) RSS palindromic hexamer

Back 89

5) RSS palindromic hexamer

It's actually the RSS palindromic heptamer

Front 90

Why do our own cells not activate the lectin pathway?
A. Our cells do not have mannose residues on their surfaces
B. Sialic acid covers the mannose sugars
C. Our cells endocytose lectin molecules as they bind
D. None of the above

Back 90

B. Sialic acid covers the mannose sugars

Front 91

In order for a cytotoxic T cell to become armed two signals are required, which of the following have those signals?

1. B cell immunoglobulin class switching and expression of IgG2a antibody
2. Recognition by TCR of specific antigen associated with class I MHC
3. Exsposure to cytokines, IL - 2 and IFN - gamma
4. Macrophage activation by Toll Like Receptors

Back 91

2 and 3

Recognition by TCR of speciifc antigen
Exposure to IL2 and IFNgamma

Front 92

In the recombination of variable-region gene segments, catalyzed by recombinase enzymes, which of the following steps immediately follows the cleavage of one strand of DNA by RAG-1 and RAG-2 at the junctures of the signal sequences and coding sequences?

A. Recognition of RSSs by recombinase enzymes
B. A free 3'-OH group attacks a phosphodiester bond forming a hairpin structure
C. Cutting of a hairpin to generate sites for P-region nucleotides
D. Addition of N-region nucleotides

Back 92

B. A free 3'-OH group attacks a phosphodiester bond forming a hairpin structure

Front 93

True or False: During rearrangement, about 2/3 of attempts of joining V-J and V-D-J units are productive.

Back 93

False. 1/3 are productive.

Front 94

Which MHC Class molecule has alpha and beta chains anchored to the cell membrane?

Back 94

MHC II has alpha and beta anchored. <--

MHC I has alpha anchored.

Front 95

MHC alleles have _________ expression.

a. complete dominant
b. semi-dominant
c. co-dominant
d. incomplete dominant

Back 95

c. co-dominant

Front 96

Which components combine to form the C5 convertase activity in the alternative pathway?

a). C4b2a3b
b). C3bBb3b
c). C4b2a
d). C3bBb

Back 96

b) C3bBb3b

Front 97

The lamda light chain in humans is located on what chromosome?

A) 16
B) 12
C) 14
D) 22

Back 97

D) 22

Front 98

Which gene segment is NOT found in a K light chain?



A)V
B)D
C)J
D)C
E) All of the above are found in a K light chain

Back 98

B) D

Front 99

Which of the following complement pathway does not require antibody binidng?

a. classical
b. alternative
c. lectin
d. b and c
e. none of the above

Back 99

d. b and c, alternative and lectin do not require antibody binding.

Front 100

Which of the following is associated with MHC molecules that are encoded by regions designated as A, B, and C?

a) MHC Class II
b) MHC Class I
c) Humans
d) Mice
e) B and C

Back 100

e) B and C

Human MHC Class I are encoded by regions designated A, B, and C.

Front 101

Which of the following complexes of the complement system is not known to be directly acted upon by regulatory proteins?



A. C5b678
B. C1r2s2
C. C5b67
D. C4b2a3b

Back 101

D. C4b2a3b

Front 102

Which of the following are gene products of the HLA gene complex?

a) C' Proteins

b) MHC Class I products
c) TNF-alpha
d) MHC Class II products
e) All of the above

Back 102

e) All of the above

C' Proteins
MHC Class I products
TNF-alpha
MHC Class II products

Front 103

Which pathway in the complement system begins with the formation of soluble antigen-antibody binding?
A. Lectin
B. Classical
C. Alternative
D. Neo-Classical
E. None of the above

Back 103

B. Classical

Front 104

Which of the following is LEAST likely to bind to MHC Class II molecule?
A- Virus
B- Bacteria
C- Transplanted Cells
D- Cancer

Back 104

D - Cancer

MHC class II molecules are most likely to bind to foreign peptides due to their exogenous pathway. Cancer as part of identifying self would rely on MHC Class I from the endogenous pathway to be removed.

Front 105

Diversity among MHC molecules is least contributed by ___________

a. gene rearrangement
b. cross over during meiosis
c. polymorphism
d. multiple alleles
e. polygenic genes

Back 105

a. gene rearrangement

Front 106

Which of the following is a major source of antibody diversity?
a) random joining of multiple V,J, and D germ-line gene segments
b) random association of heavy and light chains
c) P addition/ N addition
d) Somatic mutation
e) all of the above

Back 106

e) all of the above

Front 107

What protein blocks the formation of C3 convertase in the alternative pathway?

1. Factor I
2. C4b-binding protein
3. Factor H
4. S protein
5. C1 inhibitor

Back 107

3. Factor H

Front 108

Which one of the following is NOT true regarding the alternative complement pathway?



A. It can be triggered by infectious agents in absence of antibody.
B. It does not require C1, C2, or C4.
C. It cannot be initiated unless C3b fragments are already present.
D. It has the same terminal sequence of events as the classic pathway.

Back 108

C. It cannot be initiated unless C3b fragments are already present.

Front 109

Which of the following is matched correctly in regards to MHC Class and Region in terms of the Human HLA complex?
A. MHC Class I - D & K
B. MHC Class II - IA & IE
C. MHC Class I - B,C,A
D. MHC Class III - S

Back 109

C

All are paired correctly, however only answer choice C is related to the Human HLA complex.

Front 110

During B cell maturation (bone marrow) gene segments are randomly shuffled by genetic system capable of generating more than __________
a) 10^6 combinations
b) 10^7 combinations
c) 10^8 combinations
d) 10^9 combinations
e) None of the above

Back 110

(a) 10^6

Front 111

Which of the following molecules may inhibit the complement response?
A) C4a
B) C4b
C) C4b2a3b
D) C3bBb3b
E) C4BP

Back 111

E

C4 binding protein binds to C4b preventing the attachment of C2.

Front 112

Which statement regarding mouse skin transplantation is correct?

A. A b/b mouse parent can accept a skin graft from a k/k parent
B. A k/k mouse parent can accept a skin graft from a b/k offspring.
C. A b/k mouse offspring can accept a skin graft from a b/b parent.
D. All of the statements are true

Back 112

C. A b/k mouse offspring can accept a skin graft from a b/b parent.

Front 113

What aspect of the complement pathway causes the destruction of gram-positive cells most effectively?
A. Membrane Attack Complex
B. Mannose Binding Lectin
C. C3b opsonization
D. Antibody opsonization

Back 113

C. C3b opsonization

Front 114

Which of the following complement activation pathways is/are antibody independent?
a) Alternative Pathway
b) Classical Pathway
c) Lectin Pathway
d) A and C

Back 114

(d) A and C

Alternative and Lectin are antibody-indepdent

Front 115

Which serine protease acts to negatively regulate the complement cascade?
a. factor H
b. factor I
c. C1q
d. C3bBbC5b

Back 115

(b) factor I

Front 116

Which MHC has both alpha and beta chains?

a MHC I
b MHC II
c both
d neither

Back 116

(b) MHC II

Front 117

Which immunoglobulin genes are found on chromosome 2 in humans?

a) lamda light chain
b)kappa light chain
c) heavy chain

Back 117

(b) kappa light chain

Front 118

True or False: Class II MHC molecules typically bind to longer peptides than do class I molecules.

Back 118

True

Front 119

What is the factor used to dissociate convertase?
A. C4bBP
B. CR1
C. FactorH
D all of the above

Back 119

D. C4bBP, Cr1, and Factor H

Front 120

Which of the following statements is false?

A. T cells can only be activated by interaction between the T-cell receptor and the peptide antigen in an MHC molecule

B. There are extensive differences in MHC molecules between individuals in a population

C. MHC molecules have rigid binding sites that reduce the binding of different peptides on the surface and bind peptides with low affinity

D. A typical human expresses 6 types of MHC class I and at least12 types of MHC class II

Back 120

C. MHC molecules have rigid binding sites that reduce the binding of different peptides on the surface and bind peptides with low affinity

Is FALSE

Front 121

Activation Induced Cytidine Deaminase (AID) is involved with which of the following?

a. hyper-mutation
b. gene conversion
c. isotype switching
d. all of the above

Back 121

d. all of the above