Question 1

Which of the following best describes recombinant DNA?

Accepted Answer

DNA molecules formed by joining DNA from two different sources.

Question 2

What is the primary function of restriction enzymes in recombinant DNA technology?

Accepted Answer

To cut DNA at specific recognition sites.

Question 3

A scientist wants to clone a gene that is 120 kb in length. Which vector should they use?

Accepted Answer

Bacterial Artificial Chromosome

Question 4

During molecular cloning, why is it important to use antibiotic resistance markers?

Accepted Answer

To identify cells that have taken up the plasmid.

Question 5

Which enzyme is responsible for joining DNA fragments during the construction of recombinant DNA?

Accepted Answer

DNA ligase

Question 6

A plasmid vector is cut with a restriction enzyme that produces sticky ends. What is a possible outcome if the plasmid self-ligates?

Accepted Answer

The plasmid will not contain any foreign DNA insert.

Question 7

Which of the following is NOT a typical host organism used in recombinant DNA technology?

Accepted Answer

Plant chloroplasts

Question 8

What is the main purpose of the polymerase chain reaction (PCR) in molecular cloning?

Accepted Answer

To amplify the DNA of interest.

Question 9

Which of the following steps occurs FIRST in the process of molecular cloning?

Accepted Answer

Isolation of gene of interest

Question 10

If a researcher uses a small amount of restriction enzyme and excess DNA for a short time, what is the likely result?

Accepted Answer

Partial or incomplete digestion

Question 11

Which of the following is a real-world application of recombinant DNA technology in medicine?

Accepted Answer

Production of insulin

Question 12

A researcher wants to clone a gene and screen for successful clones using blue-white screening. Which two chemicals are required for this process?

Accepted Answer

IPTG and X-gal

Question 13

Which formula correctly represents the number of DNA molecules after $$n$$ cycles of PCR, starting with a single molecule?

Accepted Answer

$$2^n$$

Question 14

Why are palindromic recognition sites important for restriction enzymes?

Accepted Answer

They enable the formation of sticky or cohesive ends.

Question 15

Which of the following vectors can accommodate the largest DNA insert?

Accepted Answer

Yeast Artificial Chromosome

Question 16

In a cloning experiment, not all host cells will take up plasmids. What is the best method to identify cells containing recombinant DNA?

Accepted Answer

Grow cells on media containing an antibiotic.

Question 17

Which step in PCR involves the annealing of primers to the DNA sequence of interest?

Accepted Answer

Lowering the temperature to allow primers to bind

Question 18

A researcher is using a plasmid vector with an origin of replication (ori). What is the function of the ori?

Accepted Answer

To allow the plasmid to replicate independently

Question 19

Which of the following is a correct sequence of steps in molecular cloning?

Accepted Answer

Isolation of gene → Digestion with restriction enzyme → Insertion into vector → Transformation → Selection and screening

Question 20

Which of the following is NOT an application of recombinant DNA technology?

Accepted Answer

Natural selection of antibiotic-resistant bacteria

Recombinant DNA Technology and Molecular Cloning: Study Notes

Study Guide - Practice Questions