Genetics MT2 week 9 part 1 – Flashcards

Which of the following statements best describes the structure of RNA molecules in general? RNA molecules form a double helix modeled after the DNA from which they are encoded. RNA molecules are single stranded but they commonly form localized secondary structures by forming covalent bonds between regions of the molecule. RNA molecules are single stranded and they do not commonly form localized secondary structures. RNA molecules are single stranded but they commonly form localized secondary structures by base pairing between regions of the molecule.

Which of the following are classified as functional or structural RNAs? mRNAs, tRNAs, and rRNAs mRNAs and tRNAs tRNAs, rRNAs, and snRNAs Only mRNAs

Which type of RNA is translated within a cell? rRNA siRNA mRNA tRNA all of the above

If bacteria are infected with a bacteriophage and briefly exposed to radioactive uracil, what results would you expect to see immediately after exposure? radioactive DNA in the nucleus radioactive proteins in the nuclear membrane radioactive mRNA in the nucleus radioactive mRNA in the cytoplasm radioactive DNA in the cytoplasm

Which three types of RNAs are found in both prokaryotes and eukaryotes?

Name three functional RNAs unique to eukaryotes.

miRNA is capable of regulating protein production through which process?

Which type of RNA interacts with nuclear proteins to form a ribonucleoprotein complex responsible for intron removal?

The RNA transcribed from a gene will be complementary and antiparallel to which of the following? Both strands of the DNA The coding strand of the DNA The template strand of the DNA The nontemplate strand of the DNA

What is the function of the sigma subunit in bacterial RNA polymerase? Recognition of the transcriptional termination sequence Binding to the template DNA strand Specific promoter recognition and binding Elongation of the RNA during synthesis

Intrinsic termination of transcription in bacteria requires which of the following? Formation of a hairpin in the nascent RNA followed by a string of uracil nucleotides Formation of a hairpin in the nascent RNA followed by a stop codon Formation of a hairpin in the nascent RNA followed by a rut site Formation of a hairpin in the nascent RNA and the activity of rho protein

You wish to create a mutation in which you prevent access of RNA polymerase to the gene. Which region of a gene would you target? terminator sequence stop codon promoter sequence start codon coding region

A gene has acquired a mutation in which the protein product has an "extra" 50 amino acids at the end. Which region of the gene was likely mutated? promoter sequence coding region start codon terminator sequence stop codon

Which region(s) of a gene are not found within the mRNA transcript? stop codon promoter and termination regions promoter and stop codon promoter region termination region

Catalytically active RNAs that can activate processes such as self-splicing are called what?

You wish to prevent transcription of all three types of RNA in bacteria. How many different types of RNA polymerase would you need to inhibit?

Transcription of inverted repeats produces an mRNA with complementary segments that fold to form what type of secondary structure?

RNA polymerase is called a ________, meaning it is an intact complex with full enzymatic capacity.

In intrinsic termination, inverted repeat DNA sequences followed immediately by a string of ________ produce an mRNA stem-loop followed by a string of ________.

How many different RNA polymerase enzymes are required to transcribe the various classes of RNA in eukaryotic cells? Two Four or more Three One

Which eukaryotic promoters display a high degree of variability in the type, number, and location of consensus sequence elements? RNA pol III promoters for snRNA RNA pol I promoters for rRNA RNA pol III promoters for tRNA RNA pol II promoters for mRNA

You want to design a drug that prevents transcription of mRNAs but does not affect transcription of other RNAs. What enzyme would you target? RNA polymerase I RNA polymerase II methyl transferase ribozyme RNA polymerase III

You suspect a region of DNA contains a promoter and wish to confirm that a sequence of interest binds proteins. Which experiment would you use? in situ hybridization band shift assay Southern blotting pulse-chase assay northern blotting

Which assay allows you to identify the exact location of the protein-binding sequence within a promoter? western blotting DNA footprint protection assay in situ hybridization Southern blotting pulse-chase assay

Nucleoli contain many tandem repeat copies of which genes, transcribed by RNA polymerase I? tRNA rRNA mRNA siRNA all of the above

Eukaryotic promoters are diverse. How many different RNA polymerases do eukaryotes have?

A plant cell exhibits defects in transcription of transfer RNA genes. Which polymerase is likely to be mutated in this cell?

What proteins aid in the recognition of the promoter sequence and binding of RNA polymerase II in eukaryotes?

What proteins are bound to enhancers, forming a protein "bridge" that bends the DNA over the promoter to initiate transcription?

What proteins bind to silencer sequences, forming a protein "bridge" that bends the DNA over the promoter and prevents transcription?

How is the cap attached to the 5' end of eukaryotic mRNAs? By an unusual 5'-5' triphosphate linkage By a 5'-5' phosphodiester bond. By an unusual 5'-3' triphosphate linkage By a 5'-3' phosphodiester bond

Which of the following is an example of the phenomenon termed RNA editing? Co-transcriptional addition of a modified guanosine nucleoside to the 5' end of mRNA Post-transcriptional insertion of uracil nucleotides facilitated by a guide RNA Post-transcriptional addition of a poly-A tail to the 3' end of mRNA Co-transcriptional splicing of mRNA to remove introns

Which enzyme is required to initiate 5 capping of eukaryotic mRNA transcripts by removing the terminal phosphate group? ribozyme guanylyl transferase methyl transferase phosphodiesterase adenylyl cyclase

A cell has a defect in polyadenylation. Which RNA transcripts would not be affected by this defect because they are not polyadenylated? histone proteins SR proteins DNA binding proteins transcription factors transmembrane proteins

A cell exhibits specific defects in the alternative intron splicing pathway. Which proteins are likely mutated in this cell? SR proteins DNA binding proteins histone proteins transmembrane proteins transcription factors

Select the properties shared by RNA polymerase and DNA polymerase. Check all that apply. Can not proofread using a 3'-to-5' exonuclease activity Uses ribonucleotide triphosphates as substrates Catalyzes phosphodiester bond formation Dependent on a DNA sequence template Polymerizes nucleotides in a 5'-to-3' direction Can initiate strand synthesis

Wild-type E. coli grow best at 37 ∘C but can grow efficiently up to 42 ∘C. An E. coli strain has a mutation of the sigma subunit that results in an RNA polymerase holoenzyme that is stable and transcribes at wild-type levels at 37 ∘C. The mutant holoenzyme is progressively destabilized as the temperature is raised, and it completely denatures and ceases to carry out transcription at 42 ∘C. A) Relative to wild-type growth, characterize the ability of the mutant strain to carry out transcription at: A) 37 ∘C B) 40 C) 42 D) What term best characterizes the type of mutation exhibited by the mutant bacterial strain?

Microbiologists describe the processes of transcription and translation as "coupled" in bacteria. This term indicates that a bacterial mRNA can be undergoing transcription at the same moment it is also undergoing translation. Is coupling of transcription and translation possible in single-celled eukaryotes such as yeast?