Q: Which of the following is a key feature of a plasmid used as a cloning vector in recombinant DNA technology?

It must contain an origin of replication ($$\text{ori}) to $$allow independent replication.

Question 1

Which of the following best describes the process of recombinant DNA technology?

Accepted Answer

The artificial joining of DNA from two or more different sources to create new genetic combinations.

Question 2

A researcher wants to insert a human gene into a bacterial plasmid. Which enzyme is most critical for cutting both the human DNA and the plasmid at specific sites?

Accepted Answer

Restriction endonuclease

Question 3

Which of the following is a key feature of a plasmid used as a cloning vector in recombinant DNA technology?

Accepted Answer

It must contain an origin of replication ($$	ext{ori}) to $$allow independent replication.

Question 4

A scientist uses the polymerase chain reaction (PCR) to amplify a segment of DNA. Which of the following equations best represents the theoretical number of DNA copies after $$n$$ cycles, starting with a single DNA molecule?

Accepted Answer

$$N = 2^n$$

Question 5

Which of the following scenarios best illustrates the use of recombinant DNA technology in medicine?

Accepted Answer

Engineering bacteria to produce human insulin for diabetic patients.

Question 6

A gene of interest is inserted into a plasmid vector, and the recombinant plasmid is introduced into E. coli. Which process describes the uptake of this plasmid by the bacterial cells?

Accepted Answer

Transformation

Question 7

Which of the following is a potential ethical concern associated with recombinant DNA technology?

Accepted Answer

The possibility of creating genetically modified organisms that could disrupt natural ecosystems.

Question 8

A forensic scientist analyzes a crime scene sample using gel electrophoresis. Which property of DNA allows fragments to be separated in this technique?

Accepted Answer

DNA fragments are separated based on their size, with smaller fragments moving faster through the gel matrix.

Question 9

Which of the following best explains why DNA ligase is essential in recombinant DNA technology?

Accepted Answer

It joins together DNA fragments by catalyzing the formation of phosphodiester bonds.

Question 10

A patient is diagnosed with a genetic disorder caused by a single defective gene. Which recombinant DNA-based therapy could potentially treat this disorder?

Accepted Answer

Gene therapy, where a functional copy of the gene is introduced into the patient's cells.

Question 11

Which of the following is NOT a typical application of recombinant DNA technology?

Accepted Answer

Treating bacterial infections with penicillin.

Question 12

A scientist wants to confirm the presence of a recombinant plasmid in bacterial colonies. Which technique would be most appropriate for this purpose?

Accepted Answer

Colony PCR

Question 13

Which of the following statements about restriction enzymes is correct?

Accepted Answer

They recognize and cut DNA at specific palindromic sequences.

Question 14

A researcher is using a selectable marker in a plasmid vector. What is the primary purpose of this marker?

Accepted Answer

To allow identification of cells that have successfully taken up the plasmid.

Question 15

Which of the following best describes the role of reverse transcriptase in recombinant DNA technology?

Accepted Answer

It synthesizes DNA from an RNA template, allowing the creation of complementary DNA (cDNA).

Question 16

A genetically modified crop is engineered to express a bacterial gene that confers resistance to a specific insect pest. Which of the following is a potential ecological risk of this application?

Accepted Answer

The modified crop may transfer the resistance gene to wild relatives, potentially creating 'superweeds.'

Question 17

During a cloning experiment, a student forgets to add DNA ligase to the reaction. What is the most likely outcome?

Accepted Answer

The foreign DNA will not be inserted into the plasmid, as the DNA fragments will not be covalently joined.

Question 18

Which of the following equations correctly represents the relationship between the migration distance ($$d) of a $$DNA fragment in agarose gel electrophoresis and its size ($$s) in $$base pairs?

Accepted Answer

$$d \propto \frac{1}{\log(s)}$$

Question 19

A hospital is considering using gene therapy to treat a rare inherited disease. Which of the following is a valid ethical concern that should be addressed before proceeding?

Accepted Answer

The potential for unintended genetic changes that could be passed to future generations.

Question 20

Which of the following best explains why cDNA libraries are often used instead of genomic libraries when expressing eukaryotic genes in bacteria?

Accepted Answer

cDNA libraries contain only the coding sequences (exons) without introns, which bacteria cannot process.

Recombinant DNA Technology: Study Guide and Key Concepts

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