Deck 5: RNA: Transcription and Rna Processing

Question 1

The enzyme RNA polymerase synthesizes a specific RNA when provided with which of the following as a template?

A) Soluble RNA
B) Ribosomal RNA
C) Messenger RNA
D) Single-stranded DNA
E) Double-stranded DNA

Answer 1

Double-stranded DNA

Question 2

In a comparison of typical eukaryotic and prokaryotic mRNA, all of the following are true EXCEPT

A) the termini at the 5' end differ.
B) the termini at the end differ.
C) both contain regions which are not translated.
D) both may be translated before transcription is completed.
E) AUG is an initiation codon for translation in both.

Answer 2

both may be translated before transcription is completed.

Question 3

All of the following statements about the RNA polymerase are true EXCEPT which one?

A) RNA polymerase requires nucleoside triphosphates as substrates.
B) The 5'-end of the synthesized RNA contains a triphosphate.
C) The product is covalently linked to the template.
D) The product is of a specific base sequence dictated by the template.

Answer 3

The product is covalently linked to the template.

Question 4

Small nuclear RNAs such as U1, U2 and U5 affect gene expression by

A) diminishing the rate of transcription.
B) functioning as modified bases within tRNA.
C) functioning as self-catalytic components of rRNA.
D) functioning as essential components of the spliceosome.
E) promoting proper transcription termination.

Question 5

Splicing of eukaryotic mRNA precursors involves all of the following EXCEPT

A) binding of small nuclear RNAs.
B) binding of poly(A) polymerase.
C) assembly of spliceosome.
D) RNA cleavage and ligation reactions.

Question 6

RNA polymerases in eukaryotic cells

A) are localized in the post-mitochondrial cytoplasmic fraction.
B) require DNA replication to function.
C) exist in multiple molecular forms which have different specificities.
D) require a primer for chain elongation.
E) polymerize RNA chains in the to 5' direction.

Question 7

A characteristic of transcription by RNA polymerase II in eukaryotic cells is:

A) the absence of promoters elements.
B) translation initiation prior to transcription termination.
C) translation termination prior to transcription termination.
D) covalent addition of nucleotide(s) that are not encoded by DNA to the 5' and 3' ends of the transcript.
E) constitutive expression of most genes.

Question 8

Many eukaryotic and some prokaryotic genes have their coding regions interrupted by introns (intervening sequences). These intronic sequences are removed

A) during translation.
B) from messenger RNA by polyadenylation.
C) from genomic DNA by nucleases.
D) from heterogeneous nuclear RNA through a process called splicing.
E) from transfer RNA by charging which involves amino acids.

Question 9

Which ONE of the following nuclear RNA processing events is correct?

A) Many RNA transcripts have a cap of 7-methyl-guanine added to the end of the RNA.
B) The splice sites in precursors to mRNA are initially recognized by an enzyme that marks them by methylation.
C) A poly G tail of up to about 200 guanine residues is added to the end of most pre-mRNA molecules.
D) The 5'-end of many RNAs is capped using a 5'-5' pyrophosphate link.
E) After synthesis of RNA on the DNA template, ribothymidine residues in the RNA are demethylated to uridine residues.

Question 10

Splicing of pre-mRNA introns is accomplished by:

A) hydrolysis of two molecules of ATP.
B) hydrolysis of two molecules of GTP.
C) two transesterification reactions.
D) covalent attachment of guanosine to the 5'_end of the exon.
E) covalent attachment of the exon to the intron.

Question 11

Regarding RNA synthesis, which of the following statements is correct?

A) The rho subunit is required for chain initiation.
B) Synthesis of mRNA from a DNA template strand occurs in a 5 ==> direction anti-parallel to the template.
C) The first nucleotide placed in an RNA transcript of prokaryotic cells is GTP and ATP.
D) Both A and B are correct.
E) Both B and C are correct.

Question 12

Which statement is true?

A) transcription of DNA to RNA initiates at a region of the DNA called a promoter region.
B) Within a given gene, usually one strand of the DNA is copied and then the other is copied into RNA.
C) When DNA or RNA is copied this means that from the DNA sequence GCAGTTA the copy will read GCAGTTA.
D) During DNA synthesis, the primer is copied into RNA but is later removed by an exonuclease.
E) The 5' end of a DNA molecule always has the phosphate.

Question 13

Which of the following is not characteristic of tRNAs?

A) They form extensive secondary structure.
B) They have many modified bases.
C) They are spliced post-transcriptionally.
D) They get nucleotides added to their end post- transcriptionally.
E) They contain the codon for translation.

Question 14

Genes containing intervening sequences (or introns)

A) are rare in eukaryotic cells.
B) code for mRNA precursors which must be spliced before translation.
C) must undergo a DNA rearrangement before expression.
D) do not code for proteins.
E) are common in prokaryotes.

Question 15

All of the following statements about RNA polymerase and DNA polymerase are correct EXCEPT

A) both require a template.
B) both require nucleoside triphosphates as substrates.
C) both elongate in the 5' to direction.
D) both require a primer.
E) both are required for replication in certain systems.

Question 16

The beta-globin gene from a thalassemic patient was cloned and sequenced. The technician who characterized this gene informs you that a point mutation was found, but that it can not account for the thalassemia because the mutation occurred within an intron sequence. What doesn't the technician understand?

A) splicing occurs subsequent to protein synthesis.
B) Introns encode general transcription factors.
C) Intron sequences are required for transcription termination.
D) Intron sequences are required for translation termination.
E) Certain intron sequences are absolute requirements for splicing.

Question 17

Leucine zipper domains found in many transcription factors function directly in

A) DNA binding.
B) transactivation.
C) dimerization.
D) zinc binding.

Question 18

All of the following statements about ribosomes are correct EXCEPT which one?

A) All ribosomes have two subunits, the large subunit approximately twice the size of the smaller subunit.
B) Eukaryotic cells have 80S ribosomes, and protein synthesis on these ribosomes can be inhibited by cycloheximide.
C) Prokaryotic cells have 70S ribosomes, and protein synthesis on these ribosomes can be inhibited by chloramphenicol.
D) Mitochondria have 80S ribosomes, and protein synthesis on these ribosomes can be inhibited by cycloheximide.
E) The larger subunits of all ribosomes have the enzyme peptidyl transferase which forms peptide bonds.

Question 19

Eukaryotic RNA polymerase II differs from the prokaryotic RNA polymerase because it

A) retains sigma factor during elongation.
B) can incorporate either deoxy- or ribonucleotide precursors.
C) requires multiple accessory proteins.
D) transcribes only ribosomal RNA genes.
E) interacts directly with the termination factor rho.

Question 20

In what part of the mammalian cell is ribosomal RNA produced?

A) Endoplasmic reticulum
B) Mitochondrion
C) Nucleolus
D) Golgi apparatus

Question 21

What is the main function of the nucleolus?

A) Site of synthesis of ribosomal protein.
B) Site of synthesis of ribosomal RNA.
C) Site of synthesis of DNA which directs formation of transfer RNA.
D) Site of synthesis of messenger RNA.
E) Site of messenger RNA translation.

Question 22

Dimerization of transcription factor subunits accomplishes which of the following?

A) Blocks their association with DNA
B) Prevents their translocation to the nucleus
C) Increases their binding affinity for DNA
D) Targets them for degradation

Question 23

An intervening sequence is

A) more stable than coding sequences during evolution.
B) found only in beta and delta genes of globin.
C) absent or lacking in some eukaryotic genes.
D) always A-T rich.
E) always shorter than that of a coding sequence.

Question 24

The precursor for an RNA that contains a codon (near its 5' end) corresponding to an N-terminal amino acid in a protein is

A) messenger RNA.
B) heterogeneous nuclear RNA.
C) transfer RNA.
D) ribosomal RNA.
E) small nuclear RNA.

Question 25

Eukaryotic cells rRNA

A) is rapidly degraded by ribonucleases immediately after its involvement in protein synthesis.
B) is synthesized primarily in nucleoli.
C) is found in and 50S subunits of the ribosomes of the cytosol.
D) is coded for by at least two separate genes coding for 17S and 2precursor molecules.
E) has far fewer proteins associated with it than has prokaryotic rRNA.

Question 26

Synthesis of the precursor-mRNA molecule of various enzymes occurs in

A) nucleolus.
B) nucleus (excluding the nucleolus).
C) cytosol.
D) Golgi apparatus.
E) rough endoplasmic reticulum.

Question 27

Splice site recognition is determined, in part, by:

A) DNA polymerase.
B) RNA polymerase.
C) invariant sequences at the 5' and 3' ends of exons.
D) invariant sequences at the 5' and 3' ends of introns.
E) base_pairing between adjacent introns.

Question 28

Transcription elements are

A) protein factors that bind DNA.
B) DNA sequences that bind transcription factors.
C) protein factors that bind RNA polymerase.
D) DNA sequences that bind nucleosomes.

Question 29

During RNA synthesis:

A) the DNA template is read 3'_> 5' and RNA is synthesized 5'_> 3'.
B) the DNA template is read 3'_> 5' and RNA is synthesized 3'_> 5'.
C) the DNA template is read 5'_> 3' and RNA is synthesized 3'_> 5'.
D) the DNA template is read 5'_> 5' and RNA is synthesized 5'_> 3'.
E) none of the above.

Question 30

DNA-dependent RNA polymerase

A) always functions as a single polypeptide subunit.
B) is unique to oncogenic RNA viruses.
C) is involved in transcription.
D) synthesizes DNA.

Question 31

All of the following statements concerning mRNA are true EXCEPT which one?

A) RNA polymerase II is responsible for mRNA synthesis.
B) The initial transcription product is a high molecular weight precursor termed heterogeneous nuclear RNA.
C) mRNA contains a cap structure at its 5' end but hnRNA does not.
D) The leader sequence at the 5' end of the mRNA molecule does not code for any amino acids.
E) Both hnRNA and mRNA contain poly(A) at their termini.

Question 32

Which of the following statements are true only for eukaryotic transcription and processing of mRNA but not for prokaryotic? (1) transcription is regulated by the binding of proteins to specific DNA sequences upstream of the gene.
(2) The RNA is terminated at the 5' end with a cap, consisting of 7-methylguanosine connected by a triphosphate bridge.
(3) RNA polymerase locally melts the DNA strand and copies only the template strand.
(4) Non_coding regions of the RNA transcript are spliced out.
(5) The 3'_terminus of the RNA consists of a long string of A residues (poly A) which are added posttranscriptionally.

A) only 2, 3 and 4 are true
B) only 3,4 and 5 are true
C) only 1, 2 and 3 are true
D) only 2, 4 and 5 are true
E) only 1, 4 and 5 are true

Question 33

Production of a eukaryotic mRNA may involve all of the following EXCEPT

A) removal of introns and splicing.
B) capping of the 5' terminus.
C) addition of poly A at the terminus.
D) removal of intervening sequences by DNA gyrase.

Question 34

Which of the following statements concerning RNA synthesis is true?

A) All RNA is synthesized in the nucleolus.
B) 28S and 18S rRNA molecules are synthesized separately.
C) 2'-O-methylribose is selectively eliminated during processing of rRNA.
D) Poly A is added to mRNA during processing.

Question 35

During mRNA processing, splicing reactions are initiated in the branch site by which reactive group?

A) the 5'-OH of an uridylate residue
B) the 2'-OH of an adenylate residue
C) the OH of an adenylate residue
D) the OH of a guanosine co-factor
E) the 5'-phosphate of thymidine triphosphate (TTP)

Question 36

An example of a nontranscribed DNA sequence in human DNA is

A) an intron in a beta globin gene.
B) a promoter site for RNA polymerase II.
C) the termination codon for beta globin.
D) the region in ribosomal RNA genes between the segments coding for the l8S and 28S rRNAs.
E) the consensus sequence of exon-intron junctions.

Question 37

How are most of the RNA species in ribosomes synthesized?

A) by selective degradation of a single, large RNA molecule
B) on one of the ribosomal subunits
C) by condensation of two or more mRNA species
D) by translation of mRNA

Question 38

The synthesis of which of the following eukaryotic RNAs would be most severely inhibited by the mushroom toxin alpha-amanitin?

A) mitochondrial RNA
B) hnRNA
C) rRNA
D) tRNA
E) 7SL RNA

Question 39

Transcription of the major fraction of ribosomal RNA in eukaryotic cells

A) occurs in the nucleoplasm, outside of the nucleolus.
B) involves transcription from a gene which occurs twice in a diploid cell.
C) leads to a large precursor which is processed by methylation and cleavage.
D) would be inhibited by puromycin but not by actinomycin D
E) none of the above.

Question 40

Rifampicin inhibits

A) bacterial RNA polymerase.
B) eukaryotic RNA polymerase II.
C) both the bacterial and eukaryotic RNA polymerase.
D) the --> 5' exonuclease activity of DNA polymerase I.

Question 41

In eukaryotes, RNA polymerase II

A) is the most alpha-amanitin resistant polymerase.
B) is responsible for formation of tRNAs and other small RNAs.
C) often initiates transcription at complex promoters containing enhancers, silencers and TATA sequences.
D) terminates RNA synthesis and releases the RNA chain at AATAA sequences specifying end formation and polyadenylation.
E) normally utilizes bidirectional promoters.

Question 42

During nuclear processing of an pre-mRNA in a eukaryote, the portions discarded are

A) exons.
B) introns.
C) duplicate genes.
D) methylated regions.
E) poly A chains.

Question 43

Mammalian RNA polymerase II

A) synthesizes rRNA.
B) synthesizes mRNA.
C) synthesizes tRNA.
D) is least sensitive to alpha-amanitin.
E) None of the other answers is correct.

Question 44

Splicing occurs

A) in the nucleus, by removing introns from DNA.
B) in the nucleus, prior to transcription.
C) in the nucleus, either during or subsequent to transcription.
D) in the cytoplasm, prior to translation.
E) in the cytoplasm, subsequent to translation.

Question 45

If the DNA strand which is complementary to the strand of DNA which is transcribed into RNA has the following base sequence A G C T C A C T G The RNA transcribed would have which of the following sequences?

A) C A G U G A G C U
B) A G C U C A C U G
C) A G C T C A C T G
D) C A G T G A G C U
E) None of the other answers is correct.

Question 46

Which one of the following statements is true about eukaryotic RNA polymerases?

A) polymerase I is responsible for transcription of ribosomal RNA.
B) polymerase I is located in the nucleolus.
C) polymerase III is insensitive to alpha_amanitin.
D) polymerase II requires sigma factor to initiate RNA synthesis.
E) polymerase III carries out the splicing of tRNA precursors.

Question 47

Which of the following is a characteristic of transcription?

A) the reaction is driven toward product formation by hydrolysis of pyrophosphate.
B) a short primer, complementary to the DNA template, is required to initiate transcription.
C) ATP serves as the energy requirement for each new phosphodiester bond.
D) GTP serves as the energy requirement for each new phosphodiester bond.
E) the reaction is "semi_Conservative" with respect to the DNA template.

Question 48

Which one of the following is wrong? RNA splicing.

A) is responsible for the joining of V, D, and J segments in formation of a heavy chain immunoglobulin protein.
B) is sometimes an autocatalytic reaction which can occur without added proteins.
C) is often mediated by particles called spliceosomes containing both RNAs and proteins.
D) occurs in the nucleus to form a complete, translatable mRNA with a single open reading frame.
E) often results in the excision of the intron as a structure known as a lariat.

Question 49

The first step in eukaryotic pre-mRNA splicing is

A) ligation of the two exon sequences.
B) cleavage of the intron sequence at the branch site.
C) ligation of the branch site adenosine to the 5' end of the intron.
D) cleavage of the intron sequence at the 3' end.
E) ligation of U1 snRNA to the branch site.

Question 50

Capping of prokaryotic monocistronic mRNA's allows correct translation in a eukaryotic translation system. This result is evidence for

A) a role for 7-methyl-GpppNp in the recognition of mRNA by eukaryotic initiation factors and/or ribosomes.
B) a role for poly A in mRNA selection.
C) a role for F-met-tRNA in protein recognition.
D) a malfunctioning prokaryotic RNA-polymerase.
E) the production of monocistronic mRNA's in eukaryotes.

Question 51

With regard to RNA polymerases of eukaryotic cells

A) polymerase I activity is highly sensitive to inhibition by alpha-amanitin.
B) polymerase II is localized primarily in the nucleolus.
C) polymerase III is responsible for tRNA and 5S ribosomal RNA synthesis.
D) polymerase I is localized primarily in the nucleoplasm.
E) polymerase II is responsible for 18S and 28S ribosomal RNA synthesis.

Question 52

Which of the following describes the function of factor rho?

A) Rho binds RNA polymerase to the promoter region.
B) Rho brings about proper initiation of transcription.
C) Rho brings about correct termination of transcription.
D) Rho binds catabolite repressor protein to the promoter region.
E) Rho increases the rate of elongation of the growing RNA chain.

Question 53

A one nucleotide slip in the splice point on the side of the splice junction in the first intron of the beta-globin gene would result in

A) changing the reading frame of the mRNA from this point onward.
B) deletion of the rest of the beta-globin gene.
C) no change in the protein as all coding information is 5' to this junction.
D) a transition mutation.
E) a transversion mutation.

Question 54

The two largest rRNA molecules are formed

A) by partial degradation of a single, large RNA molecule.
B) on two separate genomes.
C) by condensation of two or more mRNA species.
D) by translation of mRNA.

Question 55

RNA splicing involves

A) the removal of exons.
B) the assembly of ribosomes.
C) transcription initiation factors.
D) the removal of introns.
E) DNA rearrangements.

Question 56

RNA polymerases and DNA polymerases have in common the property that they both

A) require a primer for their activity.
B) have proofreading activity.
C) synthesize polynucleotides in a 5' to 3' direction.
D) have exonuclease activity.

Question 57

Intervening sequences (introns) are

A) found in cDNA clones.
B) only found in eukaryotic DNA.
C) removed during DNA replication.
D) found in genomic DNA and hnRNA.
E) added to mRNA by the spliceosome.

Question 58

Which of the following is a correct statement about the process of transcription?

A) The process of transcription involves the formation of tRNA, rRNA, as well as mRNA.
B) transcription starts at a random DNA sequence.
C) Initiation of transcription is inhibited by actinomycinD.
D) RNA synthesized is complementary to one of the DNA strands and has the same polarity as the template strand.

Question 59

All of the following are true EXCEPT which one?

A) Most eukaryotic RNA never leaves the nucleus.
B) Essentially all types of eukaryotic RNA undergo post-transcriptional modification.
C) All forms of RNA are synthesized by some RNA polymerase.
D) The preferred template of eukaryotic RNA polymerases is double-stranded DNA.
E) The direction of RNA synthesis is to 5'.

Question 60

Which of the following is a characteristic of transcription?

A) A short primer, complementary to the DNA template, is required to initiate transcription.
B) ATP serves as the energy requirement for each new phosphodiester bond.
C) The reaction is driven toward product formation by hydrolysis of pyrophosphate.
D) The coding information is contained within the RNA polymerase.
E) The reaction is semi-conservative with respect to the DNA template.

Question 61

Which statement about introns is correct? Introns are:

A) noncoding sequences which interrupt the coding sequences of genes.
B) nontranscribed sequences which interrupt the transcribed sequences of genes.
C) regulatory elements which determine the efficiency of transcription.
D) common to the genes of all organisms.
E) unstable genetic elements which transpose randomly throughout the genome.

Question 62

The following statements are true for all known DNA polymerases. For RNA polymerases, all of the statements are true EXCEPT

A) chain growth is 5' to 3'.
B) the activated precursors are the triphosphates.
C) a divalent cation is required.
D) base pairing instructions are taken from a DNA template.
E) a primer (pre-existing polynucleotide chain) is required to initiate synthesis.

Question 63

Synthesis of mRNA

A) in eukaryotes involves more enzymes than in prokaryotes.
B) starts at the same initiation codons used during protein synthesis.
C) in prokaryotes involves a different RNA polymerase than is used for tRNA synthesis.
D) stops at the same termination codons used during protein synthesis.
E) Both B and D are true.

Question 64

How does the metabolism of rRNA differ from that of tRNA in eukaryotic cells?

A) rRNA is cleaved from a larger precursor while tRNA is transcribed as such from the transfer RNA cistrons.
B) rRNA is made in the nucleus while tRNA is synthesized in the cytoplasm.
C) The methylated bases in rRNA are added at the polymer level while in tRNA these bases are incorporated as nucleoside triphosphates.
D) rRNA forms specific complexes with proteins in the nucleus while tRNA does not.

Question 65

Which of the following statements about mRNA is correct?

A) A codon near the 5' terminus of mRNA codes for the amino acid appearing at the carboxy end of a protein.
B) The genetic information of a mRNA is present as a non-overlapping, non-punctuated sequence of nucleotide triplets read in the 5' to direction.
C) Each kind of mRNA molecule can be used for protein production only by a certain kind of ribosome of a cell.
D) All of the possible nucleotide triplets of mRNA code for amino acids.
E) A given amino acid is coded for only by a single nucleotide triplet of a given mRNA.

Question 66

The messenger RNA codon for histidine is CAU. The sequence of the DNA template strand for this mRNA is (all written 5' to

A) GTA.
B) ATG.
C) CAU.
D) CAT.
E) none of the above

Question 67

The precursor for an RNA that contains a codon (near its 5' end) corresponding to an N_terminal amino acid in a protein is

A) messenger RNA.
B) heterogeneous nuclear RNA.
C) transfer RNA.
D) ribosomal RNA.
E) small nuclear RNA.

Question 68

During splicing of pre-mRNA:

A) the energy requirement for phosphodiester formation is supplied by the spliceosome.
B) each new phosphodiester bond requires hydrolysis of one molecule of ATP.
C) each new phosphodiester bond requires hydrolysis of one molecule of GTP.
D) phosphodiester bonds are hydrolyzed and new bonds are formed subsequently by ligation.
E) the number of phosphodiester bonds remains constant.

Question 69

alpha-Amanitin is toxic to eukaryotic cells because it

A) prevents translocation of mRNA from the nucleus to the cytoplasm.
B) causes spliceosome assembly defects.
C) causes ribosome assembly defects.
D) causes protein transport defects.
E) inhibits RNA polymerase II.

Question 70

Splice site specificity is determined by:

A) conserved sequences within the intron.
B) conserved sequences within the exons.
C) U4 and U6 snRNAs.
D) RNAase III.
E) RNAase P.

Question 71

If nucleolar DNA were isolated and studied, one would find

A) it could be hybridized to saturation with ribosomal 18S RNA, and then would not hybridize with ribosomal 28SRNA.
B) it could be hybridized to saturation with ribosomal 28S RNA, and then would not hybridize with ribosomal 18SRNA.
C) it could be hybridized to saturation independently with both 18S and 28S RNA.
D) as in C, but such hybridization would show competition by messenger RNA.

Question 72

All of the following statements about ribosomes are correct EXCEPT which one?

A) 70S prokaryotic ribosomes are made up of a and a 50S subunit.
B) 80S eukaryotic ribosomes are made up of a 40S and a 60S subunit.
C) The function of rRNA is to act as mRNA for the synthesis of ribosomal proteins.
D) Eukaryotic and prokaryotic ribosomes both contain 5S RNA.
E) In eukaryotes some ribosomes are attached to the rough endoplasmic reticulum.

Question 73

The polymerase that transcribes rRNA in eukaryotes is

A) RNA polymerase I
B) RNA polymerase II
C) RNA polymerase III
D) DNA polymerase I
E) DNA polymerase III

Question 74

Which of the following RNAs are synthesized in the nucleolus?

A) 5S rRNA
B) tRNA
C) 28S rRNA
D) mRNA
E) Both A and C

Question 75

All of the following are known to be typical modifications of RNA after transcription EXCEPT

A) the hydrolytic removal of bases at a few places.
B) the cleavage of a terminal triphosphate.
C) hydrolysis to smaller units.
D) methylation of various bases.
E) methylation of a hydroxyl group of some ribose units.

Question 76

Which of the following statements is true?

A) RNA polymerase I is used to synthesize tRNA.
B) RNA polymerase III is used to transcribe mRNA.
C) RNA polymerase II is used to transcribed rRNA.
D) RNA polymerase binds enhancers.
E) Enhancers are transcription elements.

Question 77

A eukaryotic cell unable to synthesize small nuclear RNA (snRNA) would

A) be unable to process tRNA precursors.
B) be unable to splice mRNA precursors.
C) have defective ribosomes.
D) be unable to initiate RNA synthesis at the proper sites.

Question 78

The lariat structure is a characteristic of:

A) tRNA.
B) U1 SNURP.
C) the mRNA poly(A) tail.
D) an intron, prior to splicing.
E) an intron, subsequent to splicing.

Question 79

The 28S, 18S and 5.8S forms of rRNA:

A) are encoded by three distinct genetic loci that are coregulated.
B) are encoded by three distinct genetic loci that are differentially regulated according to requirements for each rRNA.
C) are encoded by a single genetic locus whose transcript is subsequently processed.
D) are encoded by a single genetic locus whose transcript is differentially amplified.
E) are the result of alternate splicing of a single transcript.

Question 80

Eukaryotic cells unable to synthesize small nuclear RNAs (snRNAs) would be unable to

A) process tRNA precursors.
B) splice mRNA precursors.
C) replicate DNA.
D) initiate RNA synthesis at the proper sites.