Eukaryotic And Archaeal Genome – Chapter 15 | Full Test Bank

Prescott's Microbiology, 11e (Willey)

Chapter 15 Eukaryotic and Archaeal Genome Replication and Expression

1) DNA replication is a complex and ungoverned process, and, as a result, the frequency of error is quite high.

2) Because of its larger size, the replication rate of eukaryotic genomes is significantly faster than the replication rate of bacterial and archaeal genomes.

3) Bacterial chromosomes, unlike eukaryotic chromosomes, often consist of a single replicon.

4) When a DNA molecule is replicated, the daughter molecules contain one strand of parental DNA and one strand of newly synthesized DNA; this is called ________ replication.

A) hemiconservative

B) conservative

C) semiconservative

D) dispersive

5) The chromosomes of most bacteria are comprised of ________.

A) double-stranded circular molecules

B) double-stranded linear molecules

C) single-stranded circular molecules

D) single-stranded linear molecules

6) Each chromosome has one or more ________ site(s) where replication begins.

A) promoter

B) replicon

C) origin

D) bifurcate

7) The transcribed, but not translated, sequence that is immediately upstream of the region that encodes the functional product is called the ________ region.

A) leader

B) promoter

C) coding

D) trailer

8) The region at which the RNA polymerase binds is the ________ region.

A) leader

B) promoter

C) coding

D) trailer

9) The unexpressed regions of split genes are called ________.

A) exons

B) endons

C) introns

D) codons

10) A bacterial ________ is the nontranscribed region of the DNA to which RNA polymerase binds in order to initiate transcription.

A) operon

B) operator

C) promoter

D) initiator

11) Split or interrupted genes have been found in eukaryotes but not in bacteria or archaea.

12) A consensus sequence in the untranslated leader sequence of a bacterial mRNA, which serves as a ribosome binding site is called the ________ - ________ sequence.

13) Splicing of eukaryotic heteronuclear RNA is catalyzed by ________.

14) In eukaryotes a so-called cap consisting of ________ is attached to the 5' end of the molecule during posttranscriptional modification of hnRNA to produce functional mRNA.

15) Eukaryotic mRNAs are modified by the addition of a poly(A) sequence at the 3' end and 7-methyl guanosine at the 5' end.

16) RNA polymerase III of eukaryotes is responsible for transcribing ________.

A) rRNA

B) mRNA

C) tRNA

D) All of the choices are correct.

17) RNA polymerase II of eukaryotes is responsible for transcribing ________.

A) rRNA

B) mRNA

C) tRNA

D) All of the choices are correct.

18) Which of the following statements is the best definition of a telomerase?

A) Telomerase is an enzyme that helps separate DNA strands.

B) Telomerase is an enzyme that helps proofread and correct newly synthesized DNA.

C) Telomerase is an enzyme that helps solve the "end replication problem."

D) Telomerase is an enzyme that cleaves introns and exons. 

19) The process by which the base sequence of all or a portion of a DNA molecule is used to direct the synthesis of an RNA molecule is called ________.

A) replication

B) transcription

C) reverse transcription

D) translation

20) In eukaryotes a series of ________ residues are added to the 3' end of an RNA molecule as part of the posttranscriptional processing used to produce functional mRNA.

A) adenine

B) guanine

C) cytosine

D) uracil

21) Key sequences exist within promoters, which vary somewhat among various promoters but are sufficiently constant that they can be represented by a sequence of bases most often found at each position. These representations are called ________ sequences.

A) convergence

B) idealized

C) consensus

D) common

22) The genetic code is translated in groups of ________ bases.

A) two

B) three

C) four

D) five

23) ________ molecules deliver amino acids to ribosomes during translation.

A) Messenger RNA (mRNA)

B) Transfer RNA (tRNA)

C) Ribosomal RNA (rRNA)

D) Heterogeneous nuclear RNA (hnRNA)

24) The process by which the base sequence of an RNA molecule is used to direct the synthesis of a protein is called ________.

A) replication

B) transcription

C) reverse transcription

D) translation

25) What is the minimum number of aminoacyl-tRNA synthetase enzymes needed to attach amino acids to all the various tRNA molecules?

A) 20

B) 61

C) 64

D) Each tRNA requires its own aminoacyl-tRNA synthetase.

26) In ________, the ribosomes can attach to the mRNA and begin translation even though transcription has not been completed.

A) bacteria

B) eukaryotes

C) fungi

D) algae

27) Ribosomes consist of ________ separate subunits that come together as part of the initiation process and dissociate immediately after termination.

A) two

B) three

C) four

D) five

28) A complex consisting of a single mRNA molecule with several ribosomes is called a ________.

A) polysome

B) multisome

C) maxisome

D) complexisome

29) In order to add a single amino acid to a growing polypeptide chain, a grand total of ________ molecules or ATP or GTP are utilized.

A) two

B) three

C) four

D) six

30) Aminoacyl-tRNA synthetases catalyze covalent addition of ________ ________ to tRNAs.

31) Proteins that recognize unfolded polypeptides and help them fold into their proper conformations are called ________.

32) Many archaeal genomes include plasmids.

33) Most archaeal mRNAs like those of eukaryotes are spliced.

34) Unlike bacteria, archaeons (except Sulfolobus) have two origins of replication.

35) Unlike bacteria, most archaeons have linear chromosomes with multiple origins of replication.

36) Archaeal promoters are most similar to those of ________.

A) viruses

B) bacteria

C) eukaryotes

D) both viruses and bacteria

37) Which of the following is incorrect about archaeal translation?

A) Archaeal translation uses 70S ribosomes, similar to bacterial ribosomes.

B) Archaeal translation may recognize ribosome binding sites homologous to bacterial Shine-Dalgarno sequences.

C) Archaeal translation uses no chaperone proteins for folding new polypeptides. 

D) Archaeal translation is coupled to transcription, similar to bacterial processes.

38) Which of the statements best describes the function of telomerase?

A) Telomerase uses internal RNA as a template for lengthening the DNA single strand and preventing information loss.

B) Telomerase stabilizes the RNA polymerase during bacterial protein transcription.

C) Telomerase is responsible for forming the Okazaki fragments that allow for noncontinuous replication.

D) Telomerase binds to specific DNA sequences that are not to be replicated and blocks polymerases.

39) Differences in eukaryotic, bacterial, and archaeal transcription are attributable to both polymerase differences and organization of protein-coding genes.

Pair the ribosomal structure with the correct organism.

40) Eukaryote A) 80S ribosome

41) Bacteria B) 70S ribosome

42) Archaea

43) The role of folding and secretion of proteins in eukaryotes and archaea is facilitated by the use of ________ protein systems.

44) Homologues of the Sec protein translocation system are found in bacteria, eukaryotes, and archaea.

45) Homologues of the nascent-chain-associated chaperone (NAC) protein folding system are found in bacteria, eukaryotes, and archaea.

46) Eukaryotic and archaeal cells are able to regulate cellular processes at which of the following levels?

A) Transcriptional

B) Translational

C) Posttranscriptional

D) Mutational

E) Physiological

47) The majority of control elements for regulation of cellular processes in eukaryotes and archaea occurs at the level of ________ initiation.

48) Enhancer sequences for transcription activation in eukaryotes can exert effects from a great distance of the transcription target by forming loops or changing DNA structural elements.

49) Eukaryotes are able to express different proteins over time or at certain points in the life cycle by using ________.

A) riboswitches

B) siRNAs

C) silencers

D) mediators

50) Which of the following RNA species mediate eukaryotic regulatory mechanisms?

A) RISC

B) miRNAs

C) siRNAs

D) tRNAs

51) The RNase known as ________ helps cut eukaryotic double-stranded RNAs to form the miRNA species.

52) A DNA site called a ________ is the binding location for a transcriptional repressor. 

53) Regulation of cellular processes via chromatin remodeling or compaction are used by eukaryotic cells but not archaeal cells. 

54) Which of the following statements is false when comparing replication in eukaryotes and bacteria?

A) Primers are made by the same RNA polymerase enzyme (primase) in both bacteria and eukaryotes.

B) In bacteria the leading and lagging strands are made by the same polymerase, whereas in eukaryotes, the strands are made by different polymerases.

C) Both bacteria and eukaryotes use an ATP-dependent DNA ligase.

D) In eukaryotes, replication is initiated by a number of proteins called the "origin recognition complex," whereas in bacteria, a single protein, DNaA, binds to the origin.

55) Transcription in archaea resembles transcription in bacteria in that archaea ________.

A) contain operons, have few, if any, introns, and use a single RNA polymerase for transcription

B) lack operons, contain introns, and use a different RNA polymerase to make mRNA, tRNA, and rRNA

C) have operons, have introns, and use a single RNA polymerase to make all types of RNA

D) lack operons, lack introns, and use a different RNA polymerase to make mRNA, tRNA, and rRNA

56) The initiation of translation in archaea ________.

A) employs Met-tRNAiMet the same as eukaryotic cells, but proceeds in a mechanism similar to bacteria

B) employs fMet-tRNAifMet the same as bacterial cells, but proceeds in a mechanism similar to eukaryotes

C) employs Met-tRNAiMet and proceeds in a mechanism similar to eukaryotic cells

D) employs fMet-tRNAifMet and proceeds in a mechanism similar to bacterial cells

57) Which of the following describes a mechanism that eukaryotic organisms can employ to alter protein production as an alternative to regulating transcription initiation?

A) RNA molecules within the spliceosome can direct alternative splicing of the primary transcript so that different proteins can be made from the same coding region.

B) A phosphorelay signal transduction mechanism directs the repression or induction of certain eukaryotic genes to regulate the protein end-products.

C) Catabolite repression plays a role in the synthesis of proteins that break down alternatives to glucose—if the substrate is not present, the proteins will not be made.

D) During times of cell starvation, the second messenger ppGpp destabilizes the DNA open complexes that code for rRNA and tRNA, saving energy by halting protein synthesis.