Question 1

Which of the following best describes the main difference between housekeeping ncRNAs and regulatory ncRNAs in eukaryotes?

Accepted Answer

Housekeeping ncRNAs are involved in basic cellular functions and are ubiquitously expressed, while regulatory ncRNAs modulate gene expression at multiple levels and are often cell-type or condition specific.

Question 2

Which experimental technique is specifically designed to globally map RNA-RNA duplexes in vivo, expanding our understanding of ncRNA-mRNA interactions?

Accepted Answer

LIGR-seq

Question 3

A mutation in a gene leads to the loss of function of PIWI proteins in animal germ cells. Which ncRNA pathway would be most directly affected, and what is a likely consequence?

Accepted Answer

The piRNA pathway; decreased silencing of transposable elements

Question 4

Which of the following is a key requirement for a functional ceRNA network according to the ceRNA hypothesis?

Accepted Answer

The relative concentration of ceRNAs and miRNAs must be sufficient to impact miRNA-mediated repression.

Question 5

Which of the following best explains how circRNAs can regulate gene expression in cancer cells?

Accepted Answer

By acting as miRNA sponges, circRNAs sequester miRNAs and prevent them from repressing their mRNA targets.

Question 6

A researcher finds that a specific lncRNA is highly expressed in undifferentiated muscle cells and acts as a molecular sponge for let-7 miRNAs. What is the likely effect of reducing this lncRNA in differentiated cells?

Accepted Answer

Increased let-7 miRNA levels and decreased expression of let-7 target genes.

Question 7

Which of the following ncRNAs is directly involved in the initiation of DNA replication and can serve as a cancer biomarker?

Accepted Answer

Y RNA

Question 8

Which of the following statements about enhancer RNAs (eRNAs) is correct?

Accepted Answer

eRNAs are transcribed from enhancer regions and can be either polyadenylated or non-polyadenylated.

Question 9

Which of the following best describes the role of the lncRNA Xist in mammalian cells?

Accepted Answer

It recruits proteins to silence transcription on the X chromosome during development.

Question 10

A scientist is studying the effect of a circRNA that binds and sequesters miR-6506-5p in gastric cancer cells. What is the most likely outcome of overexpressing this circRNA?

Accepted Answer

Increased expression of miR-6506-5p target genes, such as FOXO3, leading to tumor suppression.

Question 11

Which of the following is a distinguishing feature of piRNAs compared to miRNAs and siRNAs?

Accepted Answer

piRNAs are processed in a Dicer-independent manner from single-stranded RNA precursors.

Question 12

Which of the following best describes the function of the protein HuR in ncRNA-mediated regulatory networks?

Accepted Answer

HuR binds lincMD1 and protects it from Drosha cleavage, thereby influencing miR-133b biogenesis and muscle differentiation.

Question 13

Which of the following is NOT a typical function of small nucleolar RNAs (snoRNAs)?

Accepted Answer

Directly encoding proteins involved in splicing.

Question 14

Which of the following equations best represents the relationship between the effectiveness of a ceRNA and the number of miRNA response elements (MREs) it contains?

Accepted Answer

$$	ext{Effectiveness} \propto 	ext{Number of MREs}$$

Question 15

Which of the following best describes the role of lncRNAs in the 3D organization of the genome?

Accepted Answer

lncRNAs interact with nuclear-matrix factors to coordinate the expression of gene clusters by mediating long- and local-distance genomic interactions.

Question 16

Which of the following statements about the ceRNA network is FALSE?

Accepted Answer

All ceRNAs must be protein-coding RNAs.

Question 17

Which of the following is a real-world application of understanding ncRNA interactions in cancer therapy?

Accepted Answer

Targeting specific circRNAs that act as miRNA sponges to restore tumor suppressor gene expression.

Question 18

Which of the following best explains why not all MREs on ceRNAs are equally effective in miRNA binding?

Accepted Answer

The specific nucleotide composition of each MRE can affect its binding affinity for miRNAs.

Non-Coding RNAs and Their Integrated Networks: A Genetics Study Guide

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