Restriction Enzymes - Types and Mechanism - Unsolved Practice Set
Chapter: Biotechnology Principles and Processes | Topic: Restriction Enzymes Types and Mechanism
RESTRICTION ENZYMES - TYPES AND MECHANISM - UNSOLVED PRACTICE SET
Topic: Restriction Enzymes Types and Mechanism
Multiple Choice Questions
Q1. Restriction enzymes are often referred to as "molecular scissors" because they:
- Join DNA fragments together
- Cut DNA at specific recognition sequences
- Replicate DNA molecules
- Translate mRNA into protein
Q2. Restriction enzymes that cut DNA specifically at internal sites within the DNA molecule are called:
- Exonucleases
- Endonucleases
- Ligases
- Polymerases
Q3. Restriction enzymes typically recognise and cut DNA at specific sequences known as:
- Random sequences
- Palindromic sequences
- Non-repeating sequences only
- Sequences found only in RNA
Q4. The restriction enzyme EcoRI is named based on a convention that includes the:
- Colour of the enzyme
- Genus and species of the bacterium it was isolated from, along with a strain identification and order of discovery
- Temperature at which it works best
- Size of the DNA it cuts
Q5. When a restriction enzyme makes a staggered cut in DNA, leaving short single-stranded overhangs that can easily base-pair with complementary sequences, these are called:
- Blunt ends
- Sticky ends
- Coding ends
- Palindromic ends
Short Answer Questions
Q6. What are restriction enzymes, and why are they sometimes described as "molecular scissors"?
Q7. Differentiate between exonucleases and endonucleases.
Q8. What is a palindromic sequence in the context of restriction enzyme recognition sites?
Q9. Differentiate between sticky ends and blunt ends produced by restriction enzyme digestion.
Long Answer Questions
Q10. Explain the mechanism by which restriction enzymes recognise and cut DNA, describing the significance of palindromic recognition sequences.
Q11. Discuss the naming convention used for restriction enzymes, and explain why sticky ends produced by certain restriction enzymes are particularly useful in recombinant DNA technology.
APPLICATION / ANALYSIS
Q12. A student is trying to join two DNA fragments cut by the same restriction enzyme that produces sticky ends. Explain, using your understanding of restriction enzyme mechanisms, why using the same enzyme on both DNA fragments makes this joining process easier.
Q13. A researcher wants to insert a specific gene into a plasmid vector and needs to select a restriction enzyme that will cut both the gene and the plasmid at a compatible site, producing complementary sticky ends. Explain why this compatibility is essential for successfully inserting the gene into the plasmid.