Reference no: EM133474444

Question

1. True or False: Negative selection of transitional B cells in the spleen removes B cell clones whose BCR recognizes self antigens that weren't expressed in the bone marrow.

2. Which of the following statements about the pre-BCR is false?

a. Signals in an antigen-independent manner.

b.Consists of a rearranged immunoglobulin heavy chain paired with a surrogate light chain (VpreB + lambda5).

c. Consists of a rearranged immunoglobulin light chained with a surrogate immunoglobulin heavy chain (VpreB).

d. Transiently expressed with the IgM isotype in its constant region.

3. True or False: The class switch recombination of IgA antibodies is induced by TGF-beta or IL-21, and IgA antibodies can be transported across the placental interface as pentameric (5 member) oligomers.

4. A newborn infant has not started breastfeeding yet. Which isotype of maternal antibody/antibodies does the newborn have that they received from their mother while in utero?

a. IgG only

b. IgD only

c. IgG and IgA

d. IgE only

e. IgA only

5. Which of the following statements about the enzyme activation-induced cytidine deaminase (AID) is true?

a. Required for both somatic hypermutation and class-switch recombination in germinal center B cells

b. All of these statements are true.

c. Attacks single-stranded DNA to convert cytidine into uridine

d. Can trigger both DNA mismatch repair and DNA base-excision repair pathways.