Question 1

dCas9 is a useful tool in the CRISPER- Cas toolkit because it can_______ .&#10;A)bind DNA,but it cannot cut DNA&#10;B)fluoresce and help researchers locate target sequences&#10;C)bind DNA,but it cannot travel down the template strand&#10;D)deactivate the transcription of a gene

Accepted Answer

dCas9 is a modified version of the Cas9 protein that is commonly used in the CRISPR-Cas genome editing system. It has lost its ability to cut DNA, but it still retains the ability to specifically bind to target DNA sequences. By fusing dCas9 to other proteins or functional domains, researchers are able to use it as a tool to regulate gene expression, without introducing DNA breaks that can lead to permanent mutations.

Question 2

Examples of modifications to Cas9 include all of the following EXCEPT _______.&#10;A)epigenetic modifiers&#10;B)promotor domains&#10;C)repression domains&#10;D)fluorescent proteins

Accepted Answer

Promotor domains are not a modification made to Cas9. Cas9 modifications typically include adding functionalities like epigenetic modifiers, repression domains, or fluorescent proteins to enhance or diversify its applications in gene editing, but promotor domains are not directly modified onto Cas9 itself; they are part of the gene expression regulation in the host's DNA.

Question 3

Which of the following is a pathway available to cells to repair double- stranded DNA breaks?&#10;A)nonhomologous end- joining&#10;B)nonhomologous directed repair&#10;C)homologous directed end joining&#10;D)homologous end- joining

Accepted Answer

Nonhomologous end-joining (NHEJ) is a pathway that repairs double-stranded DNA breaks by directly ligating the break ends together without the need for a homologous template.

Question 4

CRISPR- Cas functions in bacteria to_______ .&#10;A)code for restriction enzymes&#10;B)edit genomes&#10;C)replicate viral DNA&#10;D)fight viruses

Accepted Answer

CRISPR-Cas systems function as an adaptive immune system in bacteria, providing protection against viruses by recognizing and cutting foreign DNA, such as that from invading viruses.

Question 5

The promiscuity of the CRISPER- Cas9 system likely benefits bacteria by _______.&#10;A)enabling faster search of large genomes&#10;B)increasing the safety of medical applications&#10;C)facilitating defense against new viral attacks&#10;D)continuing the evolutionary process

Accepted Answer

The CRISPER- Cas9 system is a bacterial defense mechanism against viral attacks. Its promiscuity, or tendency to target multiple genetic sequences, likely facilitates defense against new viral attacks by enabling the bacteria to adapt quickly to evolving viral genomes.

Question 6

A major limitation of CRISPER- Cas to treat human disease in vivo is modifying millions of cells.What are the characteristics of successful delivery vehicles?&#10;A)They induce an immune response.&#10;B)They are carried by erythrocytes.&#10;C)They are encapsulated in target cells via endosomes .&#10;D)They bind to target proteins.

Accepted Answer

Successful delivery vehicles should be able to efficiently deliver treatment to the intended target cells without causing an immune response or being carried by erythrocytes. Encapsulation in target cells via endosomes allows for targeted and efficient delivery of treatment. Binding to target proteins is not a necessary characteristic of delivery vehicles.

Question 7

Applications of CRISPER- Cas in biotechnology include all of the following EXCEPT _______.&#10;A)creating bioreactors to manufacture human proteins&#10;B)engineering pigs that are resistance to PRRS&#10;C)increasing drought resistance of crops&#10;D)modulating epigenetic regulation

Accepted Answer

CRISPR-Cas can be used for modulating epigenetic regulation through direct targeting of gene regulation machinery. However, it is not currently used to directly increase drought resistance in crops. A and B are valid applications of CRISPR-Cas, as it can be used to create bioreactors for protein production and engineer animals with desirable traits.

Question 8

cas genes code for a variety of proteins,including _______ .&#10;A)RNases&#10;B)crRNAs&#10;C)polysaccharides&#10;D)lysozymes

Accepted Answer

Cas genes code for proteins that include RNases, which are enzymes that degrade RNA molecules.

Question 9

Which of the following is the correct order of steps for the CRISPR- Cas mechanism?&#10;A)spacer acquisition,biogenesis,target interference&#10;B)target interference,transcription,biogenesis&#10;C)cleavage,target interference,biogenesis&#10;D)transcription,cleavage,spacer acquisition

Accepted Answer

The CRISPR-Cas mechanism follows the following steps in order: Spacer acquisition (acquisition of foreign genetic material), Biogenesis (processing of CRISPR RNA and Cas proteins), and Target interference (binding of CRISPR RNA and Cas proteins to foreign DNA and cleavage of the DNA). Therefore, option A is the correct order of steps.

Question 10

Type II CRISPR- Cas systems are the most widely used systems because _______.&#10;A)they only require a single protein,Cas9&#10;B)they use a nuclease complex&#10;C)Streptococcus pyogenes is an important research organism&#10;D)they were discovered first

Accepted Answer

Type II CRISPR-Cas systems are most widely used because they only require a single protein, Cas9, to function. This simplicity makes them easier to engineer and use in various applications, including genome editing.

Question 11

Reverse genetics is a strategy with which researchers _______.&#10;A)investigate the function of proteins&#10;B)turn on a gene and monitor the effects&#10;C)delete a genome and investigate the function of plasmids&#10;D)delete genes and monitor the effects

Accepted Answer

The answer of Reverse genetics is a strategy with which...

Question 12

The primary value of the CRISPER- Cas system in biotechnology is_______ .&#10;A)simple modifications of genomes&#10;B)addition of random indels&#10;C)the removal of ineffective genes&#10;D)rapid and cost- effective production of genetically modified organisms

Accepted Answer

The answer of The primary value of the CRISPER- Cas...

Question 13

A strategy to induce random indels in a target sequence might use_______ .&#10;A)NHEJ to ligate fragments&#10;B)NHEJ and Cas9&#10;C)HDR to match damaged and undamaged chromosomes&#10;D)HDR and a donor template

Accepted Answer

The answer of A strategy to induce random indels in...

Question 14

Which of the following is required to efficiently target DNA in vitro using CRISPER- Cas9?&#10;A)Cas9&#10;B)target RNA&#10;C)tRNA&#10;D)native crRNA

Accepted Answer

The answer of Which of the following is required to...

Question 15

Mechanisms of adaptive immunity include_______ .&#10;A)blocking phage DNA insertion&#10;B)blocking phage adsorption&#10;C)restriction enzymes&#10;D)learning from past exposures

Accepted Answer

The answer of Mechanisms of adaptive immunity include_______ .&#10;A)blocking phage...

Question 16

The primary benefit of CRISPR- Cas over TALENs and ZFNs is _______ .&#10;A)the specificity of the nuclease&#10;B)the speed of the process&#10;C)the ability of Cas9 to bind engineered sgRNA&#10;D)the cost

Accepted Answer

The answer of The primary benefit of CRISPR- Cas over...

Question 17

Genome editing is based on _______ .&#10;A)methylating specific DNA sequences with specific proteins&#10;B)transcribing specific DNA sequences with specific proteins&#10;C)acetylating specific DNA sequences with specific nucleases&#10;D)targeting and manipulating specific DNA sequences with specific nucleases

Accepted Answer

The answer of Genome editing is based on _______ .&#10;A)methylating...

Question 18

All of the following are challenges in gene therapy EXCEPT_______ .&#10;A)unknown cell types&#10;B)designing a strategy&#10;C)inaccessible tissues&#10;D)unknown specific mutations

Accepted Answer

The answer of All of the following are challenges in...

Question 19

A strategy to reduce off target effects of the CRISPER- Cas system is to limit homology with other regions of the genome.This principle capitalizes on the specificity of which step of the mechanism?&#10;A)target interference&#10;B)leader sequence determination&#10;C)spacer acquisition&#10;D)crRNA biogenesis

Accepted Answer

The answer of A strategy to reduce off target effects...

Question 20

An advantage of base editor technology is that _______.&#10;A)DNA is not cut,so there are no indels&#10;B)uracil is more specific than cytosine and enables greater fidelity&#10;C)the hybrid protein changes A to T for greater variability&#10;D)specific basic sequences are edited,leading to a more specific product

Accepted Answer

The answer of An advantage of base editor technology is...

Deck 27: CRISPR and Genomic Editing