Regulation of gene expression
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Questions and Answers

What is the primary function of differential gene expression in eukaryotes?

  • To ensure all genes are expressed
  • To produce different cell types (correct)
  • To regulate development
  • To produce identical cells

What percentage of genes are expressed in a typical human cell at any given time?

  • 100%
  • 80%
  • 50%
  • 20% (correct)

What is the purpose of gene regulation in eukaryotes?

  • To regulate development and cell specialization (correct)
  • To ensure all genes are expressed
  • To code for proteins only
  • To produce identical cells

What is the approximate percentage of DNA that codes for proteins?

<p>1.5% (B)</p> Signup and view all the answers

What is the result of abnormalities in gene expression?

<p>Diseases (D)</p> Signup and view all the answers

What is the role of differential gene expression in an organism?

<p>To produce different cell types (C)</p> Signup and view all the answers

What is the function of the remaining DNA that does not code for proteins?

<p>It codes for RNA products (A)</p> Signup and view all the answers

What is the characteristic of almost all cells in an organism?

<p>Genetically identical (C)</p> Signup and view all the answers

What is the primary function of the proteasome in protein degradation?

<p>To bind to protein molecules and degrade them (C)</p> Signup and view all the answers

What is the purpose of attaching ubiquitin to a protein molecule?

<p>To mark the protein for degradation (D)</p> Signup and view all the answers

Where does the addition of chemical groups to proteins to form glycoproteins and lipoproteins primarily occur?

<p>RER (B)</p> Signup and view all the answers

What percentage of DNA codes for proteins?

<p>1.5% (A)</p> Signup and view all the answers

What is the function of non-coding RNAs in gene expression?

<p>To regulate gene expression (C)</p> Signup and view all the answers

Where are long-lived proteins primarily degraded?

<p>Lysosome (B)</p> Signup and view all the answers

What is the term for the process of attaching ubiquitin to a protein molecule?

<p>Ubiquitination (D)</p> Signup and view all the answers

What is the size of the proteasome?

<p>26S (B)</p> Signup and view all the answers

What is the main function of non-coding DNA?

<p>To regulate gene expression (D)</p> Signup and view all the answers

What is the effect of microRNAs on mRNA?

<p>They can either degrade mRNA or block its translation (C)</p> Signup and view all the answers

What is the primary function of small interfering RNAs?

<p>To inhibit gene expression by RNA interference (A)</p> Signup and view all the answers

What is the difference between miRNA and siRNA in terms of base pairing with target mRNA?

<p>miRNA has incomplete base pairing, while siRNA has complete base pairing (C)</p> Signup and view all the answers

What is the result of chromatin modification by siRNAs?

<p>Heterochromatin formation (D)</p> Signup and view all the answers

What is the main difference between the function of miRNAs and siRNAs?

<p>miRNAs inhibit translation, while siRNAs cause mRNA degradation (C)</p> Signup and view all the answers

What is the structure of small interfering RNAs?

<p>Double-stranded RNA molecule (D)</p> Signup and view all the answers

What is the hairpin structure in miRNA biogenesis?

<p>A primary miRNA transcript (C)</p> Signup and view all the answers

What is the primary function of transcription factors?

<p>To help RNA polymerase II to initiate transcription (D)</p> Signup and view all the answers

What is the main purpose of proximal control elements?

<p>To regulate transcription by binding to transcription factors (D)</p> Signup and view all the answers

Where is the promoter typically located in a eukaryotic gene?

<p>Upstream of the gene (D)</p> Signup and view all the answers

What is the role of activators in transcription?

<p>To stimulate specific gene transcription (B)</p> Signup and view all the answers

What is the purpose of the Poly-A signal sequence?

<p>To add a poly-A tail to the mRNA (C)</p> Signup and view all the answers

What is the difference between proximal and distal control elements?

<p>Proximal control elements are located close to the promoter, while distal control elements are located far away from the gene (A)</p> Signup and view all the answers

What is the function of RNA polymerase II?

<p>To help initiate transcription (A)</p> Signup and view all the answers

What is the role of repressors in transcription?

<p>To inhibit transcription (B)</p> Signup and view all the answers

What is the function of the tumour suppressor gene p53?

<p>To initiate DNA repair and induce G1 arrest (C)</p> Signup and view all the answers

What is the primary function of histone acetylation in gene expression regulation?

<p>To relax chromatin structure (B)</p> Signup and view all the answers

What type of genes are HER-2 and Ras?

<p>Oncogenes (D)</p> Signup and view all the answers

What is the purpose of RNA processing in gene expression regulation?

<p>To modify the RNA molecule (C)</p> Signup and view all the answers

What is the role of BRCA-1 and BRCA-2 in DNA repair?

<p>To repair double-strand breaks (B)</p> Signup and view all the answers

What is the primary function of the MAPK pathway protein Ras?

<p>To transmit signals from growth factor receptors (D)</p> Signup and view all the answers

What type of regulation occurs in prokaryotic gene expression?

<p>Operon regulation (B)</p> Signup and view all the answers

What is the result of genetic changes that affect the cell cycle?

<p>Increased risk of cancer (A)</p> Signup and view all the answers

What is the function of transcription factors in eukaryotic gene expression?

<p>To help RNA polymerase II to initiate transcription (A)</p> Signup and view all the answers

What is the purpose of enhancers in eukaryotic gene expression?

<p>To stimulate specific gene transcription (A)</p> Signup and view all the answers

Where are proximal control elements typically located in a eukaryotic gene?

<p>Close to the promoter (B)</p> Signup and view all the answers

What is the role of activators in transcription?

<p>To stimulate specific gene transcription (C)</p> Signup and view all the answers

What is the function of the Poly-A signal sequence in RNA processing?

<p>To add a poly-A tail to the 3' end of mRNA (D)</p> Signup and view all the answers

What is the purpose of RNA polymerase II in eukaryotic gene expression?

<p>To initiate transcription (C)</p> Signup and view all the answers

What is the result of transcription factor binding to a specific control element?

<p>Stimulation of specific gene transcription (B)</p> Signup and view all the answers

What is the primary reason for gene expression regulation in multicellular eukaryotes?

<p>To regulate development and cell specialization (A)</p> Signup and view all the answers

What is the role of RNA molecules in gene expression regulation?

<p>They play many roles in regulating gene expression in eukaryotes (B)</p> Signup and view all the answers

What is the primary function of gene expression regulation in organisms?

<p>To regulate development and cell specialization (B)</p> Signup and view all the answers

What is the main difference between gene expression regulation in prokaryotes and eukaryotes?

<p>Eukaryotes have a more complex gene expression regulation system (C)</p> Signup and view all the answers

What is the result of abnormalities in gene expression?

<p>All of the above (D)</p> Signup and view all the answers

What is the role of non-coding RNAs in gene expression regulation?

<p>They play a role in regulating gene expression (D)</p> Signup and view all the answers

What is the primary function of chromatin structure regulation in gene expression?

<p>To regulate transcription (A)</p> Signup and view all the answers

What is the role of p53 in the cell cycle?

<p>To prevent damaged cells from replicating (A)</p> Signup and view all the answers

What happens when DNA damage is detected at the checkpoints?

<p>Cell cycle arrest occurs (B)</p> Signup and view all the answers

What is the function of CDK inhibitors?

<p>To inhibit CDK kinase activity (D)</p> Signup and view all the answers

What is the consequence of mutations in the p53 gene?

<p>Uncontrolled cell proliferation (A)</p> Signup and view all the answers

What is the role of tumour suppressor genes in the cell cycle?

<p>To regulate cell cycle progression (D)</p> Signup and view all the answers

What happens if DNA damage cannot be repaired?

<p>Apoptosis is induced (D)</p> Signup and view all the answers

What is the role of Rb in the cell cycle?

<p>To regulate cell cycle progression (B)</p> Signup and view all the answers

What is the result of translocation of DNA within the genome in Chronic Myelogenous Leukemia (CML)?

<p>Insertion of DNA downstream of an active promoter (C)</p> Signup and view all the answers

What is the effect of inserting an active promoter into a gene?

<p>Increasing the transcription of the gene (C)</p> Signup and view all the answers

What is the result of a point mutation in a proto-oncogene?

<p>A hyperactive or degradation-resistant protein is produced (A)</p> Signup and view all the answers

What is the fusion of in the Philadelphia chromosome?

<p>Gene ABL and gene BCR (A)</p> Signup and view all the answers

What is the effect of translocation of a proto-oncogene?

<p>The gene is transcriptionally activated (D)</p> Signup and view all the answers

What is the result of gene amplification within a control element?

<p>An increase in the expression of the gene (A)</p> Signup and view all the answers

What is the role of the promoter in gene transcription?

<p>To initiate the transcription of the gene (A)</p> Signup and view all the answers

What is the primary function of the tumour suppressor gene Rb?

<p>G1 arrest (B)</p> Signup and view all the answers

Which of the following genes is involved in DNA repair?

<p>BRCA-1 and BRCA-2 (B)</p> Signup and view all the answers

What is the role of histone acetylation in gene expression regulation?

<p>Regulation of chromatin structure (C)</p> Signup and view all the answers

What is the primary function of the oncogene Ras?

<p>MAPK pathway protein (B)</p> Signup and view all the answers

What is the role of oncogenes in cancer development?

<p>Promoting cell cycle progression (B)</p> Signup and view all the answers

Which of the following is a characteristic of eukaryotic gene expression regulation?

<p>Regulation of chromatin structure (C)</p> Signup and view all the answers

What is the primary function of the tumour suppressor gene p53?

<p>DNA repair and G1 arrest (B)</p> Signup and view all the answers

What is the role of noncoding RNAs in gene expression regulation?

<p>Regulation of gene expression (A)</p> Signup and view all the answers

What is the primary function of HER-2?

<p>Growth factor receptor (B)</p> Signup and view all the answers

What is the result of genetic changes that affect the cell cycle?

<p>Cancer (C)</p> Signup and view all the answers

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