Exam 3 - Chpts. 9, 10
18) Transcription is the ______. A) manufacture of a strand of RNA complementary to a strand of DNA B) manufacture of two new DNA double helices that are identical to an old DNA double helix C) modification of a strand of RNA prior to the manufacture of a protein D) manufacture of a protein based on information carried by RNA
A
23) The absence of a terminator in transcription will result in ______. A) the creation of a virus B) a strand of mRNA that lacks its cap and tail C) the production of a longer RNA molecule D) the production of a shorter RNA molecule
C
25) The expressed (coding) regions of eukaryotic genes are called ______. A) caps B) promoters C) exons D) introns
C
30) During translation, what is the correct order of events that occur as an amino acid is added? A) codon recognition, peptide bond formation, translocation B) translocation, codon recognition, termination C) initiation, codon recognition, termination D) peptide bond formation, translocation, codon recognition
A
31) Peptide bonds form between ______. A) amino acids B) an mRNA codon and a tRNA anticodon C) a tRNA and the amino acid it is carrying D) an mRNA transcript and the small ribosomal subunit
A
33) What is the smallest number of nucleotides that must be added or subtracted to change the triplet grouping of the genetic message? A) one B) two C) three D) four
A
37) Plant viruses ______. A) often use RNA, rather than DNA, as their genetic material B) benefit plants, rather than causing disease C) cause diseases that can be easily cured D) do not exist-viruses only attack animals
A
41) Examine the genetic code table, shown below. The codon AGC codes for the amino acid ______. A) serine B) arginine C) threonine D) alanine
A
46) The mutation would be most harmful to the cells if it resulted in ______. A) a single nucleotide insertion near the start of the coding sequence B) a single nucleotide deletion near the end of the coding sequence C) a single nucleotide in the middle of an intron D) deletion of a triplet near the middle of the gene
A
15) How many amino acids are common to all living systems? A) 10 B) 20 C) 30 D) 100
B
16) How many nucleotides make up a codon? A) two B) three C) four D) five
B
21) The region of DNA where RNA synthesis begins is the ______. A) start codon B) promoter C) initiator D) processor
B
22) The correct sequence of events occurring during transcription is ______. A) splicing, capping, tailing B) initiation, elongation, termination C) tailing, capping, splicing D) elongation, initiation, termination
B
26) Translation converts the information stored in ______ to ______. A) DNA... RNA B) RNA... a polypeptide C) DNA... a polypeptide D) RNA... DNA
B
28) The DNA codon AGT codes for an amino acid carried by a tRNA with the anticodon ______. A) TCU B) AGU C) TCA D) AGT
B
32) A mutation within a gene that will insert a premature stop codon in mRNA would ______. A) result in a polypeptide that is one amino acid shorter than the one produced prior to the mutation B) result in a shortened polypeptide chain C) change the location at which transcription of the next gene begins D) have the same effect as deleting a single nucleotide in the gene
B
39) HIV (human immunodeficiency virus) must use its own ______ to reproduce. A) DNA polymerase B) reverse transcriptase C) RNA polymerase D) tRNA
B
40) The figure below shows the flow of genetic information in a eukaryotic cell. The transfer of information from DNA into an RNA molecule is known as ______. A) DNA replication B) transcription C) polypeptide D) translation
B
42) Consider the following figure. It indicates that a single amino acid substitution ______. A) always involves adenine and uracil B) may alter a protein so that it no longer functions properly C) is a silent mutation D) causes a nonsense mutation
B
43) The first thing you notice is that there is no immediate increase in viruses following infection. This is because ______. A) it takes the virus time to adapt to the host B) although the virus has infected the host, it takes time to complete the lytic cycle C) the host is immune to the virus D) the virus is in a lysogenic cycle throughout the experiment
B
45) The mutation that resulted from her accident was probably ______. A) an amino acid substitution B) one that changed the triplet grouping of the genetic message C) an error in translation D) a loss in regulation of gene expression
B
14) What name is given to the collection of traits exhibited by an organism? A) holotype B) genotype C) phenotype D) morphology
C
17) The shared genetic code of all life on Earth is evidence that ______. A) the genetic code arose relatively late in the history of life on Earth B) DNA replication is error-free C) all life shares a common ancestry D) bacterial cells arose earlier than eukaryotic cells
C
19) If a strand of DNA has the sequence AAGCTC, transcription will result in a(n) ______. A) single RNA strand with the sequence TTCGAG B) DNA double helix with the sequence AAGCTC for one strand and TTCGAG for the complementary strand C) single RNA strand with the sequence UUCGAG D) RNA double helix with the sequence UUCGAG for one strand and AAGCUC for the complimentary strand
C
29) Where is translation accomplished? A) lysosomes B) smooth endoplasmic reticulum C) ribosomes D) nucleoli
C
36) How can bacteriophage DNA be spread from cell to cell without causing cell death? A) by altering the way a cell splices its RNA B) via a lytic cycle C) via a lysogenic cycle D) by altering its DNA
C
38) A(n) ______ is to bacteria as a ______ is to animal cells. A) retrovirus... virus B) phage... prophage C) prophage... provirus D) RNA virus... DNA virus
C
12) DNA replication A) is a slow process that results in virtually no errors. B) requires DNA polymerase and RNA polymerase. C) is a very fast process that results in numerous errors. D) requires the cooperation of over a dozen enzymes and other proteins.
D
13) The modern phrasing of Beadle and Tatum's hypothesis about relationships between genes and their products is "one gene-one ______." A) enzyme B) RNA C) protein D) polypeptide
D
20) Which of the following enzymes is responsible for RNA synthesis? A) RNase B) RNA helicase C) RNA ligase D) RNA polymerase
D
24) What protects mRNA from attack by cellular enzymes? A) RNA splicing B) the removal of exons C) the lack of RNA-digesting enzymes in the cytoplasm D) a cap and tail
D
27) The RNA that is translated into a polypeptide is ______ RNA. A) nuclear B) ribosomal C) transfer D) messenger
D
34) What is the ultimate source of all diversity? A) natural selection B) sexual recombination C) meiosis D) mutation
D
35) Mad cow disease is caused by A) a retrovirus similar to HIV. B) an enveloped virus. C) small circular RNA molecules called viroids. D) infectious proteins called prions.
D
44) Once viruses are detected, the number of viruses increases rapidly. This is because ______. A) lysogeny produces large numbers of bacteriophages B) DNA viruses reproduce more rapidly than RNA viruses C) the host cell speeds the release process D) the viruses lyse the hosts to release mature viruses all at once
D
