Biotechnology and Its Applications – Multiple Choice Questions (MCQs)

1. 1. The first recombinant DNA was constructed by using plasmid of which bacterium?

   • A. Escherichia coli
   • B. Salmonella typhimurium
   • C. Agrobacterium tumefaciens
   • D. Bacillus thuringiensis

2. 2. Restriction enzymes are also known as:

   • A. Molecular scissors
   • B. Molecular glue
   • C. Molecular vectors
   • D. Molecular probes

3. 3. What is the role of DNA ligase in recombinant DNA technology?

   • A. Joining DNA fragments
   • B. Cutting DNA fragments
   • C. Synthesizing DNA
   • D. Amplifying DNA

4. 4. Which of the following is commonly used as a vector for cloning genes in plants?

   • A. Ti plasmid
   • B. pBR322
   • C. Lambda phage
   • D. Cosmid

5. 5. The enzyme Taq polymerase is used in PCR because it is:

   • A. Thermostable
   • B. Cold-sensitive
   • C. pH sensitive
   • D. Light-sensitive

6. 6. ELISA is used to detect:

   • A. Antigens and antibodies
   • B. DNA
   • C. RNA
   • D. Proteins only

7. 7. Bt toxin is produced by the bacterium:

   • A. Bacillus thuringiensis
   • B. Escherichia coli
   • C. Agrobacterium tumefaciens
   • D. Salmonella typhi

8. 8. Bt cotton is resistant to which pest?

   • A. Bollworms
   • B. Aphids
   • C. Locusts
   • D. Mosquitoes

9. 9. The first transgenic cow, Rosie, produced milk enriched with:

   • A. Human alpha-lactalbumin
   • B. Vitamin A
   • C. Iron
   • D. Calcium

10. 10. RNA interference (RNAi) is used for:

    • A. Gene silencing
    • B. Gene amplification
    • C. Gene mutation
    • D. Gene recombination

11. 11. Golden Rice is a transgenic crop enriched with:

    • A. Vitamin A
    • B. Vitamin C
    • C. Vitamin D
    • D. Iron

12. 12. Gene therapy is used to treat diseases by:

    • A. Replacing a defective gene with a functional one
    • B. Introducing new genes
    • C. Suppressing gene expression
    • D. Amplifying gene expression