Match the cells in Column I with their primary function in Column II.

• (A) A-2, B-1, C-3, D-4
• (B) A-3, B-2, C-1, D-4
• (C) A-2, B-3, C-1, D-4
• (D) A-4, B-1, C-3, D-2

Arrange the following events of complement classical pathway in correct order:

A. Formation of membrane attack complex

B. Binding of C1 to antibody-antigen complex

C. Cleavage of C3

D. Formation of C5 convertase

• (A) B \(\rightarrow\) C \(\rightarrow\) D \(\rightarrow\) A
• (B) C \(\rightarrow\) B \(\rightarrow\) D \(\rightarrow\) A
• (C) B \(\rightarrow\) D \(\rightarrow\) C \(\rightarrow\) A
• (D) D \(\rightarrow\) B \(\rightarrow\) C \(\rightarrow\) A

Which immunoglobulin is primarily responsible for mucosal immunity?

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

Match the hypersensitivity type with its example.

• (A) A-3, B-1, C-2, D-4
• (B) A-1, B-3, C-4, D-2
• (C) A-3, B-2, C-1, D-4
• (D) A-4, B-1, C-2, D-3

Which molecule stabilizes the interaction between T cell receptor and MHC class II?

• (A) CD4
• (B) CD8
• (C) CD28
• (D) CD40

Match the enzyme with its function.

• (A) A-2, B-1, C-3, D-4
• (B) A-3, B-2, C-4, D-1
• (C) A-2, B-3, C-1, D-4
• (D) A-4, B-1, C-2, D-3

Arrange the steps of translation initiation in prokaryotes:

A. Binding of 50S ribosomal subunit

B. Binding of initiator tRNA

C. Binding of mRNA to 30S subunit

D. Formation of complete 70S initiation complex

• (A) C \(\rightarrow\) B \(\rightarrow\) A \(\rightarrow\) D
• (B) B \(\rightarrow\) C \(\rightarrow\) A \(\rightarrow\) D
• (C) C \(\rightarrow\) A \(\rightarrow\) B \(\rightarrow\) D
• (D) B \(\rightarrow\) A \(\rightarrow\) C \(\rightarrow\) D

The Shine--Dalgarno sequence is located in:

• (A) Promoter region
• (B) 52 untranslated region of mRNA
• (C) Coding sequence
• (D) Terminator region

Match the RNA type with its function.

• (A) A-1, B-2, C-3, D-4
• (B) A-2, B-3, C-4, D-1
• (C) A-3, B-1, C-2, D-4
• (D) A-1, B-3, C-2, D-4

Which DNA repair mechanism corrects UV-induced thymine dimers?

• (A) Base excision repair
• (B) Nucleotide excision repair
• (C) Mismatch repair
• (D) Photoreactivation only

Match the technique with its application.

• (A) A-1, B-2, C-3, D-4
• (B) A-4, B-3, C-2, D-1
• (C) A-1, B-3, C-2, D-4
• (D) A-2, B-1, C-4, D-3

Arrange steps of PCR:

A. Extension

B. Denaturation

C. Annealing

• (A) B \(\rightarrow\) C \(\rightarrow\) A
• (B) C \(\rightarrow\) B \(\rightarrow\) A
• (C) B \(\rightarrow\) A \(\rightarrow\) C
• (D) A \(\rightarrow\) C \(\rightarrow\) B

Which dye is most commonly used for DNA visualization in agarose gel?

• (A) Ethidium bromide
• (B) Crystal violet
• (C) Coomassie blue
• (D) Safranin

Match sequencing methods with key feature.

• (A) A-1, B-2, C-3, D-4
• (B) A-2, B-1, C-4, D-3
• (C) A-3, B-4, C-1, D-2
• (D) A-4, B-3, C-2, D-1

Which technique separates proteins based on isoelectric point?

• (A) SDS-PAGE
• (B) Isoelectric focusing
• (C) Gel filtration
• (D) Affinity chromatography