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027/22

The following statement is/are not true regarding superantigen like Staphylococcus
enterotoxin.

i. They activate a large number of T cells irrespective of their antigen specificity.
They bind outside the antibody binding groove directly to the lateral aspect of TCR
8 chain.

iii. They bind to the of heterodimer groove of the MHC molecules through the
V regions of TCR © and 8 chains.

They are highly resistant to proteases and denaturation by CD4+T cells.

A) iandii 8) iii and iv C) Only iii D) Only iv

Complementarity Determining Regions (CDRs) are present in the
A) Fc fragment of antibody B) Fab fragment of antibody
C) Hinge region of antibody 0) C441 and C, domains

Which of the following statement/statements is/are characteristic of secretory IgA (SIgA) ?
i. Secretory piece present in SIgA is not produced by lymphoid cells.

ii. Secretory piece is believed to protect SIgA from denaturation by bacterial proteases.

iii. SIgA (MW about 4,00,000) is a smaller molecule than serum IgA.

iv. IgA fixes complement.

A) iandii 8) iiand iii C) iiiand iv D) Only iii

The following is an/are example/examples of heterophile agglutination tests.
i. Weil-Felix test

ர்‌. Paul-Bunnel test

ii. Streptococcus MG agglutination test

iv. Widal test

A) i, ii 8) i, ii, iii ©) On iii D) i, iii, iv

Complement participates in
i. Type | hypersensitivity reaction
ii. Type Il hypersensitivity reaction
iii. Type Ill hypersensitivity reaction
iv. Type IV hypersensitivity reaction
A) iandii 8) iiand iii C) Onlyi D) ॥ and iv

Which HLA Class molecule/molecules is/are responsible for the graft-versus-host
response ?

A) HLA Class | 8) HLA Class ||

©) HLA Class III D) HLA Class | and Class III
Which of the following acts as an adjuvant in DPT vaccine ?

A) Freund's incomplete adjuvant B) Freund’s complete adjuvant
C) Bordetella pertussis D) Aluminium hydroxide

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