PCB4233 Exam 3 part 3

1.

1 point

Isotype switching is not entirely understood, however there are several factors that seem to play a role. Which of these do not play a role?

Switch recombinase such as AID

Recombination machinery such as RAG1-2

Stretches in DNA that being combined for isotype expression

Switch factors such as cytokines

2.

1 point

Which statement regarding mouse skin transplantation is correct?

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

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

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

All of the statements are true

3.

1 point

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

gene conversion

isotype switching

all of the above

hyper-mutation

4.

1 point

What aspect of the complement pathway causes the destruction of gram-positive cells most effectively?

Antibody opsonization

C3b opsonization

Mannose Binding Lectin

Membrane Attack Complex

5.

1 point

Which of the following is true regarding Tonegawa's experiment?

The DNA from embryonic cells and adult myeloma cells have the same number of restriction sites

The mRNA probe recognizes the same sequence in rearranged and germline DNA

Hybridization of the mRNA probe only ocurred in rearranged immunoglobulin genes

The mRNA probe recognizes different sequences on rearranged and germline gene segments

6.

1 point

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

It can be triggered by infectious agents in absence of antibody.

It does not require C1, C2, or C4.

It cannot be initiated unless C3b fragments are already present.

It has the same terminal sequence of events as the classic pathway.

7.

1 point

Which serine protease acts to negatively regulate the complement cascade?

factor H

C1q

C3bBbC5b

factor I

8.

1 point

Which of the following complement activation pathways is/are antibody independent?

Alternative Pathway

Classical Pathway

Lectin Pathway

A and C

9.

1 point

If DAB/2 was bred with LP what haplotype would the progeny have?

d/d

b/b

b/d

none of the above

10.

1 point

Which of the following is matched correctly in regards to MHC Class and Region in terms of the Human HLA complex?

MHC Class I - D & K

MHC Class II - IA & IE

MHC Class I - B,C,A

MHC Class III - S

11.

1 point

Class II MHC molecules typically bind to longer peptides than do class I molecules.

True

False

12.

1 point

Which of the following molecules may inhibit the complement response?

C4a

C3bBb3b

C4b2a3b

C4BP

C4b

13.

1 point

During heavy-chain rearrangement, DH gene segment first joins to a VH segment; the resulting DHVH segment then joins a JH segment to generate a VHDHJH unit.

True

False

14.

1 point

somatic mutation of immunoglobulin genes accounts for

allelic exclusion

class switching from igm to igg

affinity maturation

all of the above

none of the above

15.

1 point

All of the following statements are true, except:

C5b, C6, C7, C8, and C9 compose the membrane attack complex.

C9 has perforin-like activity.

The reaction catalyzed by factor D is C3b + B à C3bBb +Ba

C3, Factor B, and Factor I are late components of alternative pathway.

16.

1 point

The production of two different heavy-chain mRNAs allows a mature, immunocompetent B cell to express IgM and IgD with different antigenic specificity.

True

False

17.

1 point

The activation-induced cytidine deaminase (AID) is responsible for which of the following processes?

Somatic hypermutation

Gene conversion

Class switching

All of the above

None of the above

18.

1 point

Which of the following statements is false?

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

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

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

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

19.

1 point

Which immunoglobulin genes are found on chromosome 2 in humans?

heavy chain

kappa light chain

lamda light chain

20.

1 point

All of the following factors will initiate the alternative pathway of complement activation except:

Homologous erythrocytes

Gram positive bacteria

Gram negative bacteria

Agarose

21.

1 point

What is the factor used to dissociate convertase?

C4bBP

CR1

FactorH

all of the above

22.

1 point

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

Factor I

C4b-binding protein

Factor H

S protein

C1 inhibitor

23.

1 point

Diversity among MHC molecules is least contributed by ___________

gene rearrangement

cross over during meiosis

polymorphism

multiple alleles

polygenic genes

24.

1 point

Each B cell contains a single functional variable region DNA sequence for its heavy chain and another for its light chain.

True

False

25.

1 point

Which MHC has both alpha and beta chains?

MHC I

neither

both

MHC II

26.

1 point

uring B cell maturation (bone marrow) gene segments are randomly shuffled by genetic system capable of generating more than __________

10^7 combinations

10^6 combinations

10^9 combinations

10^8 combinations

27.

1 point

What enzyme is responsible for the major amplification step in the compliment pathway?

C3 convertase

Factor D

C5 convertase

C1 Convertase

28.

1 point

Which of the following is a major source of antibody diversity?

random joining of multiple V,J, and D germ-line gene segments

random association of heavy and light chains

P addition/ N addition

Somatic mutation

all of the above