8.3.2 RNA Interference (RNAi)

• What is the structure of siRNA?

  Short, double-stranded RNA
• What is RNA interference (RNAi)?

  A natural process
• What is the role of RISC in siRNA-mediated RNAi?

  Targets complementary mRNA
• What is the primary function of miRNA?

  Regulates gene expression
• Match the small RNA molecule with its source:

  siRNA ↔️ Exogenous sources

  miRNA ↔️ Encoded in the genome
• What is the key complex involved in RNAi?

  RNA-induced silencing complex
• MiRNA can lead to either mRNA degradation or translation inhibition, depending on the degree of complementarity.

  True
• siRNA targets complementary mRNA for cleavage and degradation after binding to RISC.


  True
• What is the primary function of miRNA?

  Regulate gene expression
• RNAi results in the inhibition of gene expression.

  True
• What is the structure of siRNA?

  Double-stranded RNA
• SiRNA is usually derived from exogenous sources like viral RNAs.


  True
• MiRNA is encoded in the cell's genome.


  True
• SiRNA leads to mRNA cleavage and degradation, while miRNA regulates gene expression during development.


  True
• Steps in the mechanism of miRNA-mediated RNAi

  1️⃣ MiRNA binds to RISC

  2️⃣ RISC targets complementary mRNA

  3️⃣ mRNA is degraded or translation is blocked
• What is the primary function of siRNA in cells?

  Eliminate foreign RNAs
• What is the structure of siRNA?

  Double-stranded RNA
• Small RNA molecules, siRNA and miRNA, play key roles in RNA interference
• What is the structure of miRNA?

  Single-stranded RNA
• Steps of siRNA binding and silencing

  1️⃣ RISC unwinds the double-stranded siRNA

  2️⃣ One strand of siRNA targets complementary mRNA

  3️⃣ mRNA is cleaved and degraded
• siRNA is derived from exogenous sources, while miRNA is encoded in the genome.
• siRNA and miRNA differ in their origin, structure, mechanism of action, and overall function
• What is the structure of miRNA?

  Short, single-stranded RNA
• Steps in the mechanism of siRNA-mediated RNAi

  1️⃣ SiRNA binds to RISC

  2️⃣ RISC unwinds the siRNA

  3️⃣ One strand targets complementary mRNA

  4️⃣ mRNA is cleaved and degraded
• What is the primary function of miRNA in cells?

  Regulates gene expression
• siRNA is usually derived from exogenous sources, while miRNA is encoded in the cell's genome
• siRNA is derived from exogenous sources like viruses
• How does siRNA prevent viral replication?

  Targets viral mRNA
• What complex is central to RNA interference (RNAi)?

  RISC
• miRNA-mediated silencing depends on the degree of complementarity.

  True
• What is the mechanism of siRNA-mediated silencing?

  mRNA cleavage and degradation
• RNA interference controls gene expression at the post-transcriptional
• The binding of siRNA to complementary mRNA leads to its cleavage
• MiRNA can either degrade mRNA or block its translation
• MiRNA can degrade mRNA or block its translation
• Both siRNA and miRNA-mediated RNAi result in the inhibition of gene expression.

  True
• Match the RNAi molecule with its mechanism:

  siRNA ↔️ Targets and degrades mRNA

  miRNA ↔️ Degrades mRNA or blocks translation
• What is the primary function of siRNA?

  Eliminate foreign RNAs
• miRNA is encoded in the cell's genome.


  True
• miRNA can degrade target mRNA or inhibit its translation.


  True