$$\mathrm{dsRNA} \xrightarrow{\text{Dicer}} \mathrm{siRNA}$$

Question 1

Which of the following best describes the mechanism of RNA interference (RNAi) in gene therapy?

Accepted Answer

RNAi involves the synthesis of double-stranded RNA, which is digested into siRNA fragments that guide the destruction of complementary mRNA.

Question 2

What is the primary function of ribozymes in gene therapy?

Accepted Answer

To cleave specific mRNA sequences, preventing their translation into protein.

Question 3

Which gene is commonly targeted in gene therapy for cancer due to its role as a tumor suppressor?

Accepted Answer

TP53

Question 4

In RNA interference, what is the role of the RISC complex?

Accepted Answer

It binds to siRNA and guides the destruction of complementary mutated mRNA.

Question 5

Which of the following is a real-world application of exon skipping in gene therapy?

Accepted Answer

Treatment of Duchenne muscular dystrophy by restoring the reading frame of the dystrophin gene.

Question 6

Which equation represents the process by which Dicer cleaves double-stranded RNA into siRNA fragments?

Accepted Answer

$$\mathrm{dsRNA} \xrightarrow{	ext{Dicer}} \mathrm{siRNA}$$

Question 7

Which of the following gene-blocking techniques can be used to counter the effects of dominant-negative mutations?

Accepted Answer

Antisense molecules, RNA-cleaving ribozymes, and RNA interference

Question 8

A patient with chronic myelogenous leukemia (CML) is treated with RNAi targeting the BCR-ABL fusion gene. What is the expected outcome?

Accepted Answer

Destruction of the mutated mRNA, reducing the production of the oncogenic protein.

Question 9

Which of the following statements about gene therapy for noninherited diseases is correct?

Accepted Answer

Gene therapy is increasingly used to treat cancers and acquired diseases such as AIDS.

Question 10

What is the main advantage of using RNA interference over ribozyme therapy in gene blocking?

Accepted Answer

RNA interference uses a natural cellular mechanism to silence gene expression, making it more efficient and specific than ribozyme therapy.

Question 11

Which process is illustrated by the following equation?

$$\mathrm{siRNA} + \mathrm{RISC} \rightarrow \mathrm{mRNA~degradation}$$

Accepted Answer

RNA interference

Question 12

A researcher wants to block the expression of a mutated gene causing a dominant-negative effect. Which approach would be most effective?

Accepted Answer

Delivering siRNA to silence the mutated mRNA via RNA interference.

Question 13

Which of the following is NOT a method used in gene blocking techniques?

Accepted Answer

Gene knockout using CRISPR-Cas9

Question 14

What is the expected result of using antisense molecules in gene therapy?

Accepted Answer

Antisense molecules bind to mRNA, preventing its translation into protein.

Question 15

Which of the following best explains why double-stranded RNA is used in RNA interference?

Accepted Answer

Double-stranded RNA is recognized by cellular enzymes, which process it into siRNA that guides the destruction of complementary mRNA.

Question 16

Which of the following diseases is currently being targeted by gene therapy using RNA interference?

Accepted Answer

Age-related macular degeneration

Question 17

A scientist designs a ribozyme to target the mRNA of epidermal growth factor receptor type 2 (EGFR2). What is the expected effect?

Accepted Answer

The ribozyme will cleave the EGFR2 mRNA, reducing its translation and protein production.

Question 18

Which of the following steps is essential for the success of RNA interference in gene therapy?

Accepted Answer

Synthesis of double-stranded RNA that matches the target mRNA sequence.

Question 19

What is the main challenge in using ribozyme therapy for gene blocking?

Accepted Answer

Ensuring the ribozyme reaches the target mRNA before it is translated.

Gene Blocking Techniques: Ribozymes, RNA Interference, and Gene Therapy

Study Guide - Practice Questions