Methods in Molecular Biology MCQs January 8, 2026December 31, 2024 by u930973931_answers 15 Score: 0 Attempted: 0/15 Subscribe 1. Which of the following methods is primarily used to separate DNA fragments based on their size? (A) Southern blotting (B) PCR (Polymerase Chain Reaction) (C) Gel electrophoresis (D) Northern blotting 2. In a PCR reaction, what is the purpose of the annealing step? (A) To denature the DNA template (B) To allow the primers to bind to their complementary sequences on the DNA template (C) To extend the new DNA strands (D) To degrade any contaminating DNA 3. What is the main principle behind the Sanger sequencing method? (A) Use of fluorescently labeled nucleotides for detecting sequence order (B) Use of restriction enzymes to cut DNA at specific sequences (C) Amplification of specific genes through PCR (D) Cloning of fragments into bacterial vectors 4. In the context of DNA manipulation, what does the enzyme “restriction endonuclease” do? (A) Amplifies DNA segments (B) Cuts DNA at specific sequences (C) Ligates DNA fragments (D) Repairs DNA damage 5. What is the purpose of reverse transcription in molecular biology? (A) To amplify RNA into DNA (B) To convert RNA into cDNA (complementary DNA) (C) To create RNA from DNA (D) To cleave RNA molecules at specific sequences 6. What is the primary purpose of the Northern blotting technique? (A) To detect specific DNA sequences (B) To detect specific RNA sequences (C) To amplify DNA (D) To isolate proteins 7. Which of the following is NOT typically a component of a recombinant DNA molecule? (A) Vector (B) DNA ligase (C) DNA polymerase (D) Intron 8. In the process of “Southern blotting,” what is the role of the membrane? (A) To separate DNA fragments based on size (B) To allow the transfer of DNA from the gel to a solid support for detection (C) To amplify DNA sequences (D) To detect the presence of RNA 9. In the context of protein expression, what is the role of a plasmid vector? (A) To synthesize proteins from RNA templates (B) To introduce foreign genes into a host cell for expression (C) To degrade excess protein in cells (D) To create mutations in proteins 10. In CRISPR-Cas9 gene editing, what is the function of the “guide RNA”? (A) To cut the DNA at a specific location (B) To repair the DNA after cutting (C) To direct the Cas9 protein to a specific DNA sequence (D) To provide a template for new DNA synthesis 11. Which of the following methods can be used to quantify the amount of DNA in a sample? (A) PCR (B) Gel electrophoresis (C) Spectrophotometry (D) Western blotting 12. In a typical recombinant DNA experiment, which of the following is used to seal the nicks in the DNA after cutting with restriction enzymes? (A) DNA polymerase (B) DNA ligase (C) RNA polymerase (D) Reverse transcriptase 13. Which of the following methods is best suited for amplifying a specific DNA sequence from a small sample? (A) Southern blotting (B) Polymerase Chain Reaction (PCR) (C) Western blotting (D) Gel electrophoresis 14. What is the purpose of using “reverse transcriptase” in quantitative PCR (qPCR)? (A) To transcribe DNA into RNA (B) To convert RNA into complementary DNA (cDNA) (C) To extend the DNA strand during amplification (D) To detect DNA mutations 15. Which of the following is a key advantage of next-generation sequencing (NGS) over Sanger sequencing? (A) It is more accurate (B) It requires smaller amounts of DNA (C) It allows for sequencing of entire genomes quickly and cost-effectively (D) It requires fewer steps