Question 1

Which of the following best describes the main goal of gene therapy?

Accepted Answer

To replace or modify a person's genes to treat or cure disease

Question 2

A patient with Severe Combined Immunodeficiency (SCID) is being considered for gene therapy. Which of the following best explains why gene therapy is a promising treatment for SCID?

Accepted Answer

SCID is caused by a single gene defect, so replacing the faulty gene can restore immune function.

Question 3

Which of the following is a major ethical concern associated with gene therapy?

Accepted Answer

The potential use of gene therapy for non-medical enhancements, such as intelligence or athletic ability

Question 4

Which of the following is NOT a step in the process of gene therapy using a viral vector, as shown in the provided diagrams?

Accepted Answer

Directly injecting the viral vector into the bloodstream without any gene modification

Question 5

Which of the following best explains why gene therapy treatments often need to be repeated?

Accepted Answer

The corrected gene is not always integrated into the patient's DNA and may not be passed on to new cells.

Question 6

Which of the following gene editing tools is currently the most popular for genome editing due to its efficiency and ease of use?

Accepted Answer

CRISPR/Cas9

Question 7

A researcher is using CRISPR/Cas9 to edit a gene. Which component is responsible for guiding the Cas9 nuclease to the correct DNA sequence?

Accepted Answer

Guide RNA (gRNA)

Question 8

Which of the following equations best represents the probability ($P$) that a single gene therapy treatment will result in permanent correction if the probability of gene integration per cell is $p$ and $n$ cells are treated?

Accepted Answer

$P = 1 - (1 - p)^n$

Question 9

Which of the following is a limitation of using viral vectors in gene therapy?

Accepted Answer

There is a risk of immune reactions and inflammation in the patient.

Question 10

A patient with cystic fibrosis is being considered for gene therapy. Which of the following best describes the genetic basis of cystic fibrosis that makes it a candidate for gene therapy?

Accepted Answer

It is caused by mutations in a single gene (CFTR), so replacing or repairing this gene can address the root cause.

Question 11

Which of the following best explains why gene therapy for cancer may involve modifying the patient's own cancer cells?

Accepted Answer

To add genes that stimulate the immune system to recognize and destroy cancer cells

Question 12

Which of the following statements about Zinc Finger Nucleases (ZFNs) is correct?

Accepted Answer

ZFNs are engineered proteins that use zinc finger arrays and a nuclease to break double-stranded DNA.

Question 13

Which of the following is a reason why gene therapy is not always passed on to offspring?

Accepted Answer

Most gene therapy targets somatic cells, not germline cells.

Question 14

Which of the following best describes the function of the FokI endonuclease in TALENs?

Accepted Answer

It creates a double-stranded break in the DNA at a specific location.

Question 15

A gene therapy trial for hemophilia uses stem cells from umbilical cord blood. Which of the following is a likely advantage of this approach?

Accepted Answer

Stem cells can differentiate into various blood cell types, potentially providing a long-term cure.

Question 16

Which of the following regulatory agencies must approve gene therapy products in the United States before they can be used in patients?

Accepted Answer

Food and Drug Administration (FDA)

Question 17

Which of the following is a potential risk associated with gene therapy, as observed in early SCID trials?

Accepted Answer

Development of cancer due to insertional mutagenesis

Question 18

Which of the following best describes the role of the PAM sequence in CRISPR/Cas9 gene editing?

Accepted Answer

It is required for Cas9 to recognize and bind to the target DNA sequence.

Question 19

A gene therapy protocol requires that 90% of a patient's cells receive the corrected gene for effective treatment. If the probability of successful gene delivery to a single cell is $p = 0.8$, what is the minimum number of cells ($n$) that must be treated to achieve this goal? (Use the equation $P = 1 - (1 - p)^n$ and solve for $n$ when $P = 0.9$.)

Accepted Answer

$n = \lceil \frac{\ln(1 - 0.9)}{\ln(1 - 0.8)} \rceil = 2$

Question 20

Which of the following is a challenge in distinguishing between 'good' and 'bad' uses of gene therapy?

Accepted Answer

Defining the ethical boundaries between treating disease and enhancing human traits

Gene Therapy: Principles, Applications, and Genome Editing Tools

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