Question 1

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

Accepted Answer

They cut DNA molecules at specific sequences, creating fragments with sticky or blunt ends.

Question 2

A scientist wants to amplify a specific DNA segment from a crime scene sample. Which technique should they use, and what is the key enzyme involved?

Accepted Answer

Polymerase Chain Reaction (PCR); Taq polymerase

Question 3

Which of the following statements about gel electrophoresis is correct?

Accepted Answer

Shorter DNA fragments move farther through the gel toward the positive electrode.

Question 4

A researcher is comparing gene expression in liver and brain tissues. Which technique would allow them to analyze thousands of genes simultaneously?

Accepted Answer

DNA microarray assay

Question 5

Which of the following is a major advantage of using cDNA (complementary DNA) for expressing eukaryotic genes in bacteria?

Accepted Answer

cDNA contains only exons, so bacterial cells can produce the correct protein without needing to remove introns.

Question 6

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

Accepted Answer

PCR amplification can introduce errors into the DNA sequence, while cloning in cells allows for error correction.

Question 7

A patient with a genetic disorder caused by a single defective gene is being considered for gene therapy. Which of the following is a common method for delivering the normal gene into the patient's cells?

Accepted Answer

Using a viral vector to insert the gene into somatic cells

Question 8

Which of the following is a real-world application of short tandem repeat (STR) analysis?

Accepted Answer

Identifying individuals in forensic investigations

Question 9

A scientist uses the CRISPR-Cas9 system to edit a gene in a mouse. What is the role of the guide RNA in this process?

Accepted Answer

It directs the Cas9 enzyme to the specific DNA sequence to be cut.

Question 10

Which of the following best describes a pluripotent stem cell?

Accepted Answer

A cell that can differentiate into many, but not all, cell types of the body

Question 11

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

Accepted Answer

Transfer of engineered genes to wild plant populations, creating 'super weeds'

Question 12

A researcher wants to silence the expression of a specific gene in a human cell line. Which technique would be most appropriate?

Accepted Answer

RNA interference (RNAi)

Question 13

Which of the following best describes the process of electroporation?

Accepted Answer

Applying a brief electrical pulse to cells to create temporary holes in the plasma membrane for DNA uptake

Question 14

Which of the following is a key difference between the Sanger (dideoxy chain termination) method and next-generation sequencing technologies?

Accepted Answer

Next-generation sequencing allows for high-throughput sequencing of many fragments simultaneously, while Sanger sequencing is slower and sequences one fragment at a time.

Question 15

A scientist is using RT-PCR to compare the expression of a gene in different tissues. What is the first step in this process?

Accepted Answer

Using reverse transcriptase to synthesize cDNA from mRNA

Question 16

Which of the following is a practical application of DNA-based biotechnology in medicine?

Accepted Answer

Producing human insulin using genetically engineered bacteria

Question 17

Which of the following best describes a 'knock-out' experiment in genetics?

Accepted Answer

Disabling a specific gene to study the effects on the organism's phenotype

Question 18

Which of the following is true about single nucleotide polymorphisms (SNPs)?

Accepted Answer

SNPs are single base-pair variations that can serve as genetic markers for disease-associated alleles.

Question 19

Which of the following is a reason why cloned animals, such as Dolly the sheep, may not be identical to their genetic donor?

Accepted Answer

Epigenetic differences, such as DNA methylation and histone modification, can affect gene expression.

Question 20

Which of the following best describes the main ethical concern regarding therapeutic cloning?

Accepted Answer

The destruction of human embryos to obtain embryonic stem cells

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

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