Practice for Quiz 2

Gene knockouts and gene knockdowns differ in their mechanisms and biological outcomes. Which of the following best describes this difference?

• Gene knockouts completely eliminate gene function, while gene knockdowns reduce gene expression without fully eliminating it.

• Gene knockouts increase gene expression, while gene knockdowns decrease gene expression.

• Gene knockouts and gene knockdowns both increase gene function.

• Gene knockdowns completely eliminate gene function, while gene knockouts only reduce gene expression.

Tags

NGSS.HS-LS3-2

CRISPR-Cas9-mediated gene editing involves which of the following mechanisms, including the roles of PAM, gRNA, and Cas9?

• Cas9 uses gRNA to target specific DNA sequences adjacent to a PAM site and introduces double-strand breaks.

• Cas9 randomly cuts DNA without guidance from gRNA or PAM.

• gRNA binds to PAM sites and edits DNA without Cas9 involvement.

• PAM sequences directly edit DNA without the need for Cas9 or gRNA.

The two main pathways cells use to repair double-stranded breaks caused by CRISPR-Cas9 are:

• Non-homologous end joining and homologous recombination

• Base excision repair and nucleotide excision repair

• Mismatch repair and direct reversal

• Photoreactivation and translesion synthesis

The therapeutic potential and limitations of CRISPR technologies can be described as:

• CRISPR offers precise gene editing for treating genetic diseases but faces challenges like off-target effects and ethical concerns.

• CRISPR is only used for agricultural modifications and has no medical applications.

• CRISPR technologies are completely risk-free and have no limitations in therapy.

• CRISPR can only be used in bacteria and is not applicable to human therapy.

Tags

NGSS.HS-ETS1-3

RNA interference (RNAi) leads to gene silencing in eukaryotes by which of the following mechanisms?

• Degrading target mRNA molecules

• Increasing transcription of target genes

• Stabilizing mRNA to enhance translation

• Promoting DNA replication

The roles of siRNA, miRNA, and piRNA in gene regulation and development can be compared as follows:

• siRNA, miRNA, and piRNA all regulate gene expression, but siRNA and miRNA mainly silence genes post-transcriptionally, while piRNA primarily protects the genome from transposable elements in germ cells.

• siRNA, miRNA, and piRNA all activate gene expression in somatic cells only.

• siRNA and miRNA are only involved in DNA replication, while piRNA is involved in protein synthesis.

• siRNA, miRNA, and piRNA all function exclusively in the nucleus to promote gene expression.

Challenges in delivery and specificity of CRISPR technologies in therapeutic contexts include:

• Efficient targeting and minimizing off-target effects

• Increasing the size of CRISPR components

• Reducing the cost of laboratory equipment

• Enhancing the color of CRISPR proteins

Tags

NGSS.HS-ETS1-3

Argonaute plays a key role in RNA interference by being a core component of which complex?

• RNA-induced silencing complex (RISC)

• Spliceosome

• Ribosome

• Exosome

The evolutionary origin and purpose of RNA interference in eukaryotes is best described as:

• A defense mechanism against viruses and transposable elements

• A process for synthesizing proteins directly from DNA

• A method for increasing mutation rates in the genome

• A pathway for producing ribosomal RNA

CRISPR can be used in research to determine the function of an unknown gene by:

• disrupting the gene and observing the resulting phenotype

• amplifying the gene to increase its expression

• sequencing the gene to identify its structure

• transferring the gene to another organism without modification