CRISPR

Section Title

After you've completed the tutorial, click the button below to answer questions about what you've learned.

Tutorial Comprehension Quiz

You must watch the entire tutorial before you can take the quiz.

After you've completed the tutorial, click the button below to answer questions about what you've learned.

Tutorial Comprehension Quiz

Question 1 of 10

Question

The CRISPR/Cas9 system requires all of the following enzymatic activities except:

ligase.

endonuclease.

polymerase.

exonuclease.

All of the above are required.

Correct.

Incorrect.

Question

The CRISPR/Cas9 system can be considered a bacterial “adaptive immune system” because:

it prevents phages from injecting their nucleic acids into bacteria.

it requires short palindromic regions to function.

it stores molecular elements of infectious agents to use to fight off future infection by those agents.

it initiates the production of antibodies specific to the infectious agent.

it is able to predict which phage will infect a bacterium in the future.

Correct.

Incorrect.

Question

The CRISPR/Cas9 system is able to target (and then cleave) invading phage DNA using:

a randomly generated DNA sequence complementary to part of that phage DNA and bound to Cas9.

RNA complementary to part of that phage DNA and bound to Cas9.

machinery that recognizes all foreign DNA.

a randomly generated RNA sequence complementary to part of that phage DNA and bound to Cas9.

DNA complementary to part of that phage DNA and bound to Cas9.

Correct.

Incorrect.

Question

The CRISPR/Cas9 system has been transferred to mammals and other animals and used to edit genes. This is possible for all of the following reasons except the following:

Eukaryotic cells have DNA repair mechanisms that CRISPR/Cas9 can take advantage of.

CRISPR/Cas9 can be easily inserted into animal cells.

Biomolecules—RNA, DNA, proteins—work in virtually the same manner in all organisms.

CRISPR/Cas9 allows very specific sequence replacement.

CRISPR/Cas9 is able to override the immune systems of these animals.

Correct.

Incorrect.

Question

If a CRISPR/Cas9–like immune system existed naturally in humans, as well as in bacteria, what would you search for as indications of such a system?

Known viral sequences inserted in the human genome

Clusters of repeated sequences with homology to infectious agents in the human genome

Small untranslated RNAs with short areas of homology to infectious agents

A protein with homology to Cas9

All of the above.

Correct.

Incorrect.

Question

Why is it necessary to incorporate the invading viral DNA into the bacterial genome?

This prevents infection from the invading virus.

This is the only way the virus can transcribe and translate its DNA for infection.

This causes the viral DNA to be degraded.

The bacterium can now transcribe the section of the viral gene to create CRISPR/Cas9 complexes.

The invading viral DNA is not incorporated into the genome.

Correct.

Incorrect.

Question

In a bacterium, the guide RNA in the CRISPR/Cas9 system originates from:

DNA from the bacterial genome.

DNA from an invading pathogen.

RNA from the bacterial genome.

RNA from an invading pathogen.

a DNA-RNA hybrid created by researchers.

Correct.

Incorrect.

Question

Once one CRISPR/Cas9 molecule is made against an invading pathogen, it is active against all invading pathogens.

True

False

Correct.

Incorrect.

Question

As in the simulation, you attempt to edit a mouse genome to produce a mottled mouse, yet the mouse that you edited still has black fur like its parents. Why did this mouse not have the mottled phenotype you engineered?

Mottled fur is a dominant trait, so you would have to wait for the offspring of the engineered mouse to see the desired phenotype.

The CRISPR/Cas9 system cannot be used successfully in mammals, so you would not see any mottled mice.

One or both of the guide RNAs did not cut either allele of the target gene.

You have to edit both alleles of the gene; otherwise, you will not see the mottled phenotype.

The skin color gene was edited in the wrong cell type.

Correct.

Incorrect.

Question

Which type(s) of mutation can be created using the CRISPR/Cas9 system?

Deletion of a splicing enhancer of a gene

Point mutations in the coding region of a gene

Excision of enhancer sites that lie at a distance downstream and upstream of a gene

Deletion of a single codon in the coding region of a gene

All of these answer choices are correct.

Correct.

Incorrect.

Chapter 1. CRISPR

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