Question 1

Which of the following best describes the principle behind nucleic acid hybridization?

Accepted Answer

The base pairing of one strand of nucleic acid to the complementary sequence on another strand.

Question 2

Which enzyme is responsible for sealing the bonds between restriction fragments during the creation of recombinant DNA?

Accepted Answer

DNA ligase

Question 3

A scientist wants to amplify a specific DNA segment from a 40,000-year-old woolly mammoth sample. Which technique should they use?

Accepted Answer

Polymerase chain reaction (PCR)

Question 4

Which of the following is a key advantage of 'third-generation sequencing' over previous sequencing methods?

Accepted Answer

It sequences a single long DNA molecule as it moves through a nanopore, allowing for faster and less expensive sequencing.

Question 5

Why are bacterial plasmids commonly used as cloning vectors in gene cloning?

Accepted Answer

They replicate separately from the bacterial chromosome and can be rapidly multiplied.

Question 6

A researcher is trying to express a human gene in bacteria, but the gene contains introns. What is the best strategy to ensure successful expression?

Accepted Answer

Use cDNA synthesized from the gene's mRNA, which contains only exons.

Question 7

Which of the following best explains why PCR cannot fully substitute for gene cloning in cells?

Accepted Answer

PCR amplification occasionally incorporates errors into the amplified strands.

Question 8

In gel electrophoresis, why do shorter DNA fragments move faster through the gel than longer fragments?

Accepted Answer

Shorter fragments encounter less resistance moving through the microscopic holes in the gel.

Question 9

Which of the following is a real-world application of DNA microarray assays?

Accepted Answer

Comparing patterns of gene expression in different tissues or under different conditions, such as fetal testing.

Question 10

A scientist uses the CRISPR-Cas9 system to knock out a gene in mosquitoes to prevent them from transmitting malaria. What is this application called?

Accepted Answer

Gene drive

Question 11

Which of the following best describes a stem cell?

Accepted Answer

A relatively unspecialized cell that can reproduce itself indefinitely and differentiate into specialized cell types under certain conditions.

Question 12

What is the main difference between embryonic stem (ES) cells and adult stem cells?

Accepted Answer

ES cells are pluripotent and can differentiate into many cell types, while adult stem cells can generate only a limited number of cell types.

Question 13

Which of the following is a potential ethical concern associated with gene therapy and gene editing?

Accepted Answer

The potential for deliberate efforts to control the genetic makeup of human populations (eugenics).

Question 14

A patient with chronic myelogenous leukemia (CML) is treated with imatinib. What is the mechanism of action of this drug?

Accepted Answer

It inhibits overexpression of a specific leukemia-causing tyrosine kinase.

Question 15

Which of the following best describes the use of short tandem repeats (STRs) in forensic science?

Accepted Answer

STRs are variations in the number of repeats of specific DNA sequences, analyzed by PCR and gel electrophoresis to create genetic profiles.

Question 16

A plant cell that can generate a complete new organism is called:

Accepted Answer

Totipotent

Question 17

Which of the following is a limitation of animal cloning by nuclear transplantation?

Accepted Answer

Many cloned animals exhibit defects due to incomplete reprogramming and epigenetic changes.

Question 18

What is the main goal of therapeutic cloning?

Accepted Answer

To produce cells for treating disease.

Question 19

Which of the following is a benefit of using induced pluripotent stem (iPS) cells in regenerative medicine?

Accepted Answer

iPS cells can be generated from a patient’s own cells, reducing ethical concerns and risk of immune rejection.

Question 20

Which of the following is a potential environmental concern related to genetically modified (GM) crops?

Accepted Answer

GM crops may transfer genes to wild plants, producing 'super weeds'.

DNA Tools and Biotechnology: Techniques, Applications, and Ethical Considerations

Study Guide - Practice Questions