Deck 4: Antibody Structure and Function

Question 1

Kappa or lambda light chains:

A) are encoded on the same chromosome
B) associate with only one type of heavy chain at a time
C) can be expressed by the same B cell
D) are expressed by a pre-B cell

Answer 1

associate with only one type of heavy chain at a time

Question 2

All polymeric but not monomeric immunoglobulins are characterized by:

A) a secretory component
B) an extra H-chain domain
C) a J chain
D) high carbohydrate content

Answer 2

a J chain

Question 3

Variations in immunoglobulin structure that occur because of the use of different constant region domains are known as:

A) allotypes
B) idiotypes
C) isotypes
D) autotypes

Answer 3

isotypes

Question 4

When papain is used to cleave antibody molecules,what are the products?

A) 2 Fab and Fc
B) two L chains and two H chains
C) VL,CL,VH,and CH

Question 5

Which immunoglobulin appears in the highest titer in the secondary response?

A) IgG
B) IgA
C) IgM
D) IgD

Question 6

Which region of the immunoglobulin molecule can bind antigen?

A) Fab
B) CL
C) CH

Question 7

The antigen specificity of a B cell is determined:

A) after interaction with antigen
B) by H and L chain variable region sequences
C) only by the L chain
D) after isotype switching

Question 8

The idiotype of an antibody is located on which region?

A) CH
B) CL
C) VH + VL
D) Fc

Question 9

Which of the following characteristics is true of an anamnestic response compared to a primary response? An anamnestic response has:

A) a shorter lag phase
B) a longer lag phase
C) antibodies that decline quickly
D) predominately IgM antibodies

Question 10

Which immunoglobulin appears first in the primary response?

A) IgG
B) IgM
C) IgA
D) IgE

Question 11

All of the following are functions of immunoglobulins EXCEPT:

A) neutralization of toxic substances
B) facilitating phagocytosis through opsonization
C) interacting with cytotoxic T cells to lyse viruses
D) combining with complement to destroy cellular antigens

Question 12

Which of the following is an accurate statement about monoclonal antibodies? Monoclonal antibodies are:

A) a population of antibodies that all recognize a single specific antigen
B) a population of antibodies that arise from single B cell
C) used to classify and identify specific cellular membrane antigens
D) all of the above

Question 13

Which immunoglobulin can cross the placenta?

A) IgM
B) IgE
C) IgA
D) IgG

Question 14

An immunoglobulin that contains a peptide that is not synthesized by a B cell is:

A) IgM in serum
B) IgA in secretions
C) IgG in secretions
D) IgD on a B cell membrane

Question 15

The primary response is characterized by:

A) naive B cells recognizing antigens
B) memory B cells recognizing antigens
C) the production of large amounts of IgG
D) a very short lag period
E) a long duration of high titer

Question 16

The function of IgD is to:

A) protect the newborn
B) activate complement
C) protect the mucosa
D) bind antigen as a B-cell surface receptor

Question 17

The ability of an antibody to opsonize is located in which region?

A) F(ab)'2
B) Fc
C) VL + VC
D) hypervariable regions

Question 18

Which immunoglobulin activates the classical complement pathway?

A) IgD
B) IgM
C) IgA
D) IgE

Question 19

Which of the following immunoglobulins is found in only trace amounts in the serum?

A) IgM
B) IgG
C) IgD
D) IgA

Question 20

Which of the following pairings of immunoglobulin and a property are true?

A) IgA: crosses the placenta
B) IgG: most abundant in serum
C) IgM: immunoglobulin produced by a T cell
D) IgE: major immunoglobulin of secondary response

Question 21

What is the main function of IgD?

A) It helps in class switching.
B) It is a primary response antibody.
C) It protects mucous membranes.
D) It offers protection to newborns.

Question 22

All of the following are true of IgM EXCEPT:

A) It can cross the placenta.
B) It fixes complement.
C) It is a primary response antibody.
D) It can bind up to ten antigens.

Question 23

Which antibody is able to cross the placenta?

A) IgA
B) IgG
C) IgM
D) IgE

Question 24

Somatic mutation of immunoglobulin genes accounts for:

A) allelic exclusion
B) class switching from IgM to IgG
C) affinity maturation
D) creation of the isotype

Question 25

Bence-Jones proteins are identical to which of the following?

A) secretory IgA
B) heavy chains
C) light chains
D) IgG molecules

Question 26

Which of the following is true of a secondary response to an antigen?

A) Equal amounts of IgM and IgG are made.
B) IgG is increased 100 to 1000 times.
C) IgM is increased 100 fold.
D) The lag time is the same as the primary response.

Question 27

Which of the following is true of coding for antibody molecules?

A) Heavy chains are coded for on chromosome 2.
B) V,D,and J code for heavy chain variable regions.
C) DNA coding for light chains are rearranged first.
D) V and D code for light chain variable regions.

Question 28

Which of the following is true of IgE?

A) It fixes complement.
B) It binds to mast cells.
C) It is found on mucosal surfaces.
D) It participates in agglutination reactions.

Question 29

Which represents an isotype of a heavy chain?

A) kappa
B) beta
C) epsilon
D) lambda

Question 30

IgD is produced by:

A) differential splicing of the RNA transcript
B) differential splicing of the DNA transcript
C) constant gene region rearrangement
D) immature B cells

Question 31

All of the following are characteristic of secretory IgA EXCEPT:

A) It is found on mucosal surfaces.
B) It has a secretory component made in epithelial cells.
C) It occurs as a monomer.
D) It defends against pathogens in the respiratory tract.

Question 32

IgA in the secretions has a valence of:

A) one
B) two
C) four
D) ten

Question 33

Which of the following is the first step in immunoglobulin gene rearrangement?

A) light-chain variable region
B) light-chain constant region
C) heavy-chain variable region
D) heavy-chain constant region

Question 34

The receptor for antigen on a mature naive B cell is:

A) MHC class I
B) IgG
C) IgM
D) MHC class II

Question 35

The valence of an IgG antibody molecule is:

A) one
B) two
C) four
D) ten

Question 36

The region of an antibody molecule that exhibits the greatest variability from antibody to antibody is known as the:

A) hypervariable region
B) constant region
C) Fc region
D) all of the above

Question 37

Which class makes up 70 to 80 percent of total serum immunoglobulins?

A) IgA
B) IgG
C) IgM
D) IgE

Question 38

Immunoglobulins are grouped into classes on the basis of similarities in which of the following?

A) light chains
B) heavy chains
C) antigen binding sites
D) disulfide bonds

Question 39

The combination of a plasma cell fused to a myeloma cell is called a:

A) melanoma
B) hybridoma
C) mycetoma
D) myeloma

Question 40

All of the following are true of IgA EXCEPT:

A) It is found in secretions.
B) It fixes complement.
C) It is a monomer in serum.
D) It is important in oral immunizations.

Question 41

Immunoglobulins IgG,IgM,IgA,and IgD represent which of the following?

A) isotypes
B) allotypes
C) idiotypes
D) heterotypes

Question 42

The theory that lymphocytes are preprogrammed to respond to a particular type of antigen best describes:

A) the clonal selection theory
B) Ehrlich's side chain theory
C) the spontaneous generation theory
D) Edelman's antibody formation theory

Question 43

The antibody found on mucosal surfaces that acts as a first line of defense is called:

A) IgA
B) IgD
C) IgE
D) IgM

Question 44

In serum protein electrophoresis,which band contains the immunoglobulins?

A) alpha-1
B) alpha-2
C) beta
D) gamma

Question 45

Which antibody agglutinates and fixes complement best?

A) IgA
B) IgM
C) IgG
D) IgE

Question 46

Which immunoglobulin causes allergic reactions due to release of histamine from mast cells?

A) IgA
B) IgE
C) IgD
D) IgM

Question 47

The antibody that appears first in an immune response and is a pentamer with a molecular weight of 900,000 best describes:

A) IgM
B) IgD
C) IgA
D) IgG

Question 48

Which antibody is found in the greatest supply and is the only one capable of crossing the placenta?

A) IgA
B) IgD
C) IgE
D) IgG

Question 49

Papain cleavage of IgG results in which of the following?

A) 2Fab and an Fc fragment
B) Fab2 and Fc' fragment
C) two light chains
D) two heavy chains joined together

Question 50

Which is the main purpose of the secretory component that is part of IgA?

A) transports across endothelial cells
B) combines with antigen
C) joins the two monomers
D) involved in class switching

Question 51

Which antibody is found mainly as a dimer in mucosal secretions?

A) IgA
B) IgD
C) IgE
D) IgG

Question 52

Which best describes monoclonal antibody?

A) antibody made against multiple epitopes
B) antibody made by a variety of B cells
C) antibody made from a single antibody-producing cell
D) all antibody of any one particular class

Question 53

Where on an antibody molecule does combination with antigen take place?

A) variable region
B) constant region
C) hinge region
D) Fc region

Question 54

Which of the following best characterizes IgD?

A) primary response antibody
B) surface receptor for antigen
C) responsible for allergic reactions
D) fixes complement

Question 55

Which of the following is true of IgE?

A) fixes complement
B) binds to mast cells
C) found on mucosal surfaces
D) participates in agglutination reactions

Question 56

A Fab fragment consists of:

A) two heavy chains
B) two light chains
C) one light chain and one-half of a heavy chain
D) one light chain and an entire heavy chain

Question 57

All of the following are characteristic of IgE EXCEPT:

A) found on mast cells and basophils
B) fixes complement
C) found in low amounts in the blood
D) causes allergic reactions

Question 58

In serum electrophoresis conducted at pH 8.6,which protein group migrates the fastest?

A) albumin
B) alpha-1 globulin
C) alpha-2 globulin
D) gamma globulin

Question 59

The antibody found on B cells that is thought to be involved in B cell maturation is:

A) IgA
B) IgD
C) IgE
D) IgM

Question 60

All of the following are true of IgG EXCEPT:

A) first class of antibody to appear
B) able to cross the placental barrier
C) the predominant antibody in serum
D) provides immunity for the newborn

Question 61

IgG differs from IgM in which way?

A) IgM can cross the placenta.
B) IgG can bind more antigens than IgM.
C) IgG is the main antibody in serum.
D) Only IgM has kappa light chains.

Question 62

The primary response differs from the secondary immune response in what way?

A) Amounts of IgG and IgM are the same.
B) The lag time is shorter.
C) Amounts of IgG increase greatly.
D) More memory cells are involved.