Deck 17: Non-Coding Rnas

Question 1

Select possible outcomes after RISC binds to an mRNA during RNA interference. Choose all that apply.

A) Inhibition of translation without mRNA degradation
B) mRNA degradation
C) Movement of the RISC-mRNA complex to a P-body
D) Expulsion of the RISC-mRNA complex from the cell
E) Cell death

Answer 1

A, B, C

Question 2

You are working in a lab that studies ncRNAs. You develop an assay to isolate ncRNAs and any associated molecules. You must then identify the molecules you have isolated. You find a molecule that is associated with an ncRNA that is not changed by protease, RNase, or DNase. The associated molecule is most likely

A) a small molecule.
B) a protein.
C) an mRNA.
D) DNA.

Answer 2

A

Question 3

You are working in a lab that studies snoRNAs. You mutate the antisense sequences in a C/D box snoRNA to completely different sequences. What results do you expect compared to wild type snoRNA? Check all that apply.

A) Reduced binding of the snoRNA to the rRNA
B) Reduced methylated ribose in the rRNA
C) Reduced psuedouracil in the rRNA
D) Increased binding of the snoRNA to the rRNA
E) Increased methylated ribose in the rRNA

Answer 3

A, B

Question 4

An RNA molecule with catalytic activity is called a(n)

A) ribozyme.
B) ncRNA.
C) snRNA
D) miRNA.

Question 5

Into which gene of the CRISPR-Cas system are fragments of bacteriophage DNA inserted?

A) Crispr
B) tracr
C) Cas9
D) Cas1
E) Cas2

Question 6

Select the ncRNA that facilitates the binding of telomerase to the telomere and acts as a template for DNA replication.

A) TERC
B) snRNA
C) SRP RNA
D) Xist RNA

Question 7

Select functions that ncRNAs can perform. Choose all that apply.

A) Scaffold
B) Guide
C) Ribozyme
D) Blocker
E) Decoy

Question 8

SmY RNAs are a family of ncRNAs in nematodes that are thought to be involved in a special type of RNA splicing. Based on this function, SmY RNAs are most likely members of which category of ncRNAs?

A) snRNA
B) tRNA
C) snoRNA
D) siRNA

Question 9

Select the ways in which modifications to the chromatin brought about by HOTAIR and associated proteins are proposed to inhibit transcription.

A) Direct inhibition of RNA polymerase binding
B) Attraction of other chromatin-modifying enzymes
C) Formation of a double stranded RNA structure between HOTAIR and the mRNA preventing translation
D) Recruitment of repressors to the DNA

Question 10

With which injection did Mello and Fire observe the lowest amount of mex-3 probe staining?

A) Injected with double-stranded RNA
B) Injected with mex-3 antisense RNA
C) Uninjected

Question 11

A bacterial ncRNA called OxyS regulates translation by binding to the Shine-Dalgarno sequence, which prevents ribosome binding. What is the function of this ncRNA?

A) Blocker
B) Decoy
C) Ribozyme
D) Scaffold

Question 12

The ncRNA HOTAIR recruits what type of proteins to target genes?

A) Histone-modifying complexes
B) Transcription factors
C) RNA polymerase
D) Histone acetyltransferase

Question 13

Ribozymes are RNA molecules with what type of activity?

A) Catalytic
B) Binding
C) Protease
D) Decoy

Question 14

Consider the two key roles that have been identified for SRP RNA. You have isolated a mutant SRP RNA. This RNA is able to perform its role as a scaffold for SRP proteins, but has lost its other function. How will this affect translation of SRP-containing proteins?

A) Partially translated proteins will be stuck in the cytosol.
B) Partially translated proteins will be stuck in the ER lumen.
C) Partially translated proteins will be stuck in the nucleus.
D) Translation will proceed normally.

Question 15

In an in vitro translation assay radioactive amino acids can be incorporated into proteins and the proteins separated from the unincorporated amino acids (higher counts per minute indicates more protein synthesis). Given the following data what are the conclusions that you would come to?

A) Double stranded RNA is more efficient at inhibiting translation than antisense RNA
B) Antisense RNA is more efficient at inhibiting translation than double stranded RNA
C) No conclusion about the efficiency of translation inhibition can be made as the positive and negative controls did not perform appropriately
D) The experiment did not work since the antisense fibronectin did not have an effect on amino acid incorporation.

Question 16

What ability, which modern eukaryotic cells also possess, did cells in an RNA world probably acquire that explains the existence of DNA?

A) Reverse transcription
B) DNA replication
C) Translation
D) RNA splicing

Question 17

In order of their occurrence what are the steps in RNA interference?

A) Processing of RNA transcript by DGCR8, transport to cytoplasm, processing by Dicer, binding to RISC, binding to target mRNA
B) Processing by Dicer, processing of RNA transcript by DGCR8, transport to cytoplasm, binding to RISC, binding to target mRNA
C) Processing of RNA transcript by DGCR8, processing by Dicer, transport to cytoplasm, binding to RISC, binding to target mRNA
D) Processing of RNA transcript by DGCR8, binding to RISC, transport to cytoplasm, processing by Dicer, binding to target mRNA

Question 18

Select the four most common types of molecules to which ncRNAs bind.

A) DNA
B) RNA
C) Proteins
D) Small molecules
E) Lipids

Question 19

What is the make up of the bacterial and eukaryotic SRP, respectively?

A) Bacterial: 1 ncRNA, 1 protein; Eukaryotic: 1 ncRNA, 6 proteins
B) Bacterial: 1 ncRNA, 1 protein; Eukaryotic: 6 ncRNAs, 1 protein
C) Bacterial: 1 ncRNA, 6 proteins; Eukaryotic: 1 ncRNA, 6 proteins
D) Bacterial: 6 ncRNAs, 1 protein; Eukaryotic: 1 ncRNA, 1 protein

Question 20

Select the features that made protobionts possible precursors of living cells.

A) A boundary separating the internal contents of the protobiont from the external environment
B) Polymers inside the protobiont contained information.
C) Polymers inside the protobiont had catalytic functions.
D) Capability of self-replication
E) Presence of organelles

Question 21

piRNA sequences are complimentary to

A) mRNA from a transposable element.
B) another RNA within the piRISC.
C) the Crispr gene.
D) bacteriophage DNA.

Question 22

The CRISPR-Cas system in bacteria is most similar to what system in vertebrates?

A) Immune system
B) Circulatory system
C) Nervous system
D) Digestive system

Question 23

What is the name of the type of chemical modification on anti-miRNA oligonucleotides used to inhibit miRNA function that involves ribose sugars with an extra bridge connecting the 2' oxygen and the 4' carbon?

A) Locked nucleic acids
B) Antagomirs
C) Enoxacin
D) RNaseMRP

Question 24

Abnormal levels of miRNAs are associated with nearly all forms of what type of human disease?

A) Neurological disorders
B) Cancer
C) Cardiovascular disease
D) Gastrointestinal disease

Question 25

You work in a lab that is studying piRISCs and PIWI proteins. You have isolated piRISCs from a cell. What would be one way to identify which piRISCs are involved in cleaving TE RNA vs. those that halt transcription?

A) One of the proteins in the pRISC that halts transcription should have a nuclear localization signal.
B) One of the proteins in the pRISC that halts transcription should have nuclease activity.
C) One of the proteins in the pRISC that halts transcription should have acetylation activity.
D) One of the proteins in the pRISC that halts transcription should function as a transcription factor.

Question 26

What human disease is associated with mutations in Drosha?

A) Familial amyotrophic lateral sclerosis
B) Alzheimer disease
C) Heart arrhythmias
D) Lung cancer

Question 27

Based on what you know about cartilage-hair hypoplasia, which strategy involving ncRNAs do you anticipate would be useful in treating this disease?

A) A viral vector to restore a particular miRNA
B) Anti-miRNA oligonucleotides
C) Targeting of the miRNA-processing machinery
D) Use of DNA demethylating agents and histone deacetylase inhibitors