Class 12 Biology (NCERT)

1. The two core techniques that form the foundation of modern biotechnology are:

• A. Genetic engineering and bioprocess technology
• B. Microbiology and cell biology alone
• C. Classical breeding methods alone
• D. Fermentation technology alone

2. Restriction endonucleases are specialized enzymes that function to:

• A. Cut DNA molecules at specific recognition sequences
• B. Join separate DNA fragments together
• C. Synthesize entirely new DNA strands
• D. Degrade RNA molecules exclusively

3. The enzyme used to join (ligate) DNA fragments together during recombinant DNA technology is:

• A. DNA ligase
• B. DNA polymerase
• C. Restriction endonuclease
• D. RNA polymerase

4. A vector commonly used to carry and introduce foreign DNA into a host cell is a:

• A. Plasmid
• B. Ribosome
• C. Mitochondrion
• D. Lysosome

5. The Polymerase Chain Reaction (PCR) technique is primarily used to:

• A. Rapidly amplify a specific segment of DNA into many copies
• B. Cut DNA molecules at specific recognition sites
• C. Sequence an organism's entire genome directly
• D. Translate an mRNA sequence into a protein

6. Gel electrophoresis is a laboratory technique used to:

• A. Separate DNA fragments primarily based on their size
• B. Amplify a given DNA sequence
• C. Cut DNA molecules at specific sites
• D. Synthesize entirely new proteins

7. Competent cells, used during the process of genetic transformation, are host cells that have been specially treated to:

• A. Take up foreign DNA more readily from their surroundings
• B. Naturally resist all types of antibiotics
• C. Produce significantly more cellular energy
• D. Divide at an unusually rapid rate

8. The bacterium most commonly used as a host organism in recombinant DNA technology experiments is:

• A. Escherichia coli
• B. Streptococcus
• C. Rhizobium
• D. Lactobacillus

9. A bioreactor is a specialized vessel primarily used to:

• A. Grow large volumes of cells for the industrial production of useful biological products
• B. Cut and join DNA fragments together
• C. Separate DNA fragments according to their size
• D. Determine the complete sequence of a DNA molecule

10. Downstream processing in a biotechnological process refers to:

• A. The purification and processing of a product after it has been biosynthesized
• B. The very first step involved in gene cloning
• C. Solely the process of DNA amplification
• D. Solely the step of cutting DNA with enzymes

11. The origin of replication (ori) sequence present in a vector is responsible for:

• A. Enabling the vector to replicate independently within the host cell
• B. Cutting any foreign DNA that is inserted
• C. Simply marking the vector for later selection
• D. Encoding a completely unrelated foreign protein

12. Selectable marker genes present in a cloning vector primarily help to:

• A. Identify and eliminate host cells that have not been successfully transformed
• B. Increase the overall mutation rate of the host cell
• C. Make the vector replicate at a significantly faster rate
• D. Cut foreign DNA at specific recognition sites