PCB4233 Exam 3 part 2

Which of the following is least correct concerning somatic hypermutation?

Which pathway in the complement system begins with the formation of soluble antigen-antibody binding?

Activation of complement occurs via 3 different pathways. Which is NOT one of those pathways?

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 mutant cell line, RMA-S, expreses only about 5% of the normal levels of class I MHC molecules on its membrane. However, RMA-S cells synthesize normal levels of class I alpha chains and beta-2 microglobulin. When predigested peptides are fed to this cell line, class I MHC expression is restored. Which of the following might be a plausible explanation for the decreased membrane expression of class I MHC in RMA-S?
I. a defect in the ubiquitination of endogenous antigens
II. mutations in TAP (transporter associated with antigen processing) that make this protein nonfunctional
III. mutations in calnexin, calreticulin, or tapsain that result in loss of function
IV. absence of functional invariant chains
V. absence of HLD-DM

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?

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

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.

All of the following are properties of the Major Histocompatibility Complex except:

Vk gene segments sometimes join to C-lamda gene segments.

Which of the following is least correct:

Which of the following statements is CORRECT?

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

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

Which pathway is more closely associated with innate immunity than with adaptive immunity?

Which of the following are produced from B-cells that have matured in the peripheral lymphoid organs?

Which of the following is NOT involved in recombination of immunoglobulin heavy-chain genes?

What is the function of C1 inhibitor (C1Inh) in regulating the classical pathway of the complement cascade?

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

The 2 turn RSS includes a:

Which of the following is a correct match between the human chromosome number and its corresponding product?

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

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

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

Muscle cells, liver hepatocytes, neural cells, and fibroblast express very high levels of class I MHC molecules?

Human cells are able to avoid activation of the lectin pathway by:

Of the following, which accurately represents the gene sequence found in heavy chain DNA?

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

What involves or is involved with allelic exclusion?

A deficiency in which of the following is specifically associated with a rise in hereditary angioedema?

The lectin pathway of complement activation does not target human cells as they normally have sialic acid residues covering the sugar groups recognized by MBL and so they do not act as targets for binding.

MHC alleles have _________ expression.

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

Which of the following is responsible for acting as a complement inhibitor by preventing the polymerization of C9 and consequently inhibiting MAC formation?

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?

The complement component C3c mediates which of the following biological effects:

Which of the following is LEAST likely to bind to MHC Class II molecule?

hen does somatic hypermutation occur during B cell growth?
1. In the bone marrow
2. When it is a progenitor B cell
3. In the Peripheral lymphoid organ
4. After it is mature.

Which of the following regulates C3b and C4b by cleaving and inactivating these components of the complement cascade?

Which of the following does NOT contribute to Ig gene diversity?

Which of the following is FALSE regarding class MHC II molecules?

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

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

Which of the following statements about the alternative pathway is least correct?

Which of these is NOT something both MHC I and II have in common?

Why do our own cells not activate the lectin pathway?

The pioneering Tonegawa and Hozumi experiment of 1976 established all of the following EXCEPT:

Which answer is FALSE regarding heavy chain rearrangement?

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

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