Question 1

Which of the following best describes the function of restriction enzymes in recombinant DNA technology?

Accepted Answer

They cut DNA at specific recognition sequences, producing fragments with sticky or blunt ends.

Question 2

A researcher wants to clone a gene into a plasmid vector and identify recombinant colonies using blue-white screening. Which colonies should be selected for further study?

Accepted Answer

Ampicillin Resistant/White

Question 3

Which feature is NOT essential for a good cloning vector?

Accepted Answer

The ability to carry DNA fragments of up to 200 kb

Question 4

What is the primary purpose of the lacZ gene in plasmid vectors used for blue-white screening?

Accepted Answer

To allow identification of recombinant plasmids by disrupting its function when DNA is inserted

Question 5

Which of the following statements about palindromic DNA sequences is correct?

Accepted Answer

They are sequences that read the same on both strands in the 5' to 3' direction.

Question 6

Which equation best represents the exponential amplification of DNA during PCR, where $$n is $$the number of cycles?

Accepted Answer

$$2^n$$

Question 7

A scientist is constructing a cDNA library from cancerous tissue. Which enzyme is essential for synthesizing cDNA from mRNA?

Accepted Answer

Reverse transcriptase

Question 8

Which step in the PCR process is responsible for separating double-stranded DNA into single strands?

Accepted Answer

Denaturation

Question 9

Agarose gel electrophoresis separates DNA fragments based on which property?

Accepted Answer

Fragment size

Question 10

Which of the following is a limitation of PCR?

Accepted Answer

It requires knowledge of the nucleotide sequence to design primers.

Question 11

In Sanger sequencing, what is the role of dideoxynucleotides (ddNTPs)?

Accepted Answer

They terminate DNA synthesis by lacking a 3' hydroxyl group.

Question 12

Which repair mechanism is used by eukaryotic cells after Cas9-induced double-stranded breaks to introduce insertions or deletions?

Accepted Answer

Nonhomologous end-joining (NHEJ)

Question 13

A knockout mouse is created by disrupting the reading frame of a gene using homologous recombination. What is the expected outcome?

Accepted Answer

The mouse will express a nonfunctional protein for the targeted gene.

Question 14

Which of the following best describes the function of a probe in library screening?

Accepted Answer

A probe is a labeled DNA or RNA sequence complementary to the target gene, used to identify specific clones.

Question 15

Which equation would you use to calculate the number of DNA molecules after $$n$$ cycles of PCR, starting with a single molecule?

Accepted Answer

$$2^n$$

Question 16

Which of the following is a real-world application of CRISPR-Cas9 genome editing?

Accepted Answer

Creation of tomatoes that ripen quickly

Question 17

What is the main advantage of next-generation sequencing (NGS) technologies over traditional Sanger sequencing?

Accepted Answer

NGS can sequence tens of thousands of DNA strands simultaneously, generating massive amounts of data rapidly.

Question 18

Which of the following statements about bacterial plasmid vectors is correct?

Accepted Answer

They must contain multiple cloning sites with restriction enzyme recognition sequences.

Question 19

Which technique is used to study patterns of gene expression by analyzing RNA production in cells and tissues?

Accepted Answer

Northern blot analysis

Question 20

A scientist uses fluorescent in situ hybridization (FISH) to visualize gene expression in a zebrafish embryo. What is the main benefit of FISH compared to traditional blotting techniques?

Accepted Answer

FISH allows direct hybridization of probes to chromosomes or RNA in situ, enabling visualization within tissues or whole organisms.

Chapter 17: Recombinant DNA Technology – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards