Chapter 8

Question 1

Allelic Exclusion

Answer 1

A process by which only one allele of a gene is expressed while the other is silenced.

• Ensures that each B cell & T cell synthesizes only one heavy & one light chain

Question 2

Allotypes

Answer 2

Allelic forms expressed in an individual

Question 3

Deletion

Answer 3

A mutation (a genetic aberration) in which a part of a chromosome or a sequence of DNA is missing

Question 4

Inversion

Answer 4

An inversion occurs when a single chromosome undergoes breakage and rearrangement within itself.

Question 5

Junctional Diversity

Answer 5

Describes the DNA sequence variations introduced by the improper joining of gene segments during the process of V(D)J recombination.

Question 6

Recombinases

Answer 6

• Recombination enzymes
• Generate TCRs

Question 7

Isotype Switch

Answer 7

A biological mechanism that changes a B cell’s production of immunoglobulin (antibodies) from one type to another, such as from the isotype IgM to the isotype IgG.

Question 8

Memory B Cells

Answer 8

Held in reserve against future exposures to antigen.

• Better explaination: [A B cell sub-type that are formed within germinal centers following primary infection and are important in generating an accelerated and more robust antibody-mediated immune response in the case of re-infection (also known as asecondary immune response).]

Question 9

Somatic Hypermutation

Answer 9

Provides additional variation that ‘fine-tunes” the antibody responses to antigens that are frequently or chronically present.

Question 10

Affinity Maturation

Answer 10

The interaction of antibody with a given epitope becomes tighter & more effective over time.