Deck 7: Microbial Genetics

Question 1

Which of the following is NOT a characteristic of Okazaki fragments?

A) They are checked for accuracy by DNA polymerase III.
B) They make up the lagging strand of replicated DNA.
C) They begin with an RNA primer.
D) They are joined together by DNA ligase.
E) They are longer in eukaryotic cells.

Answer 1

E

Question 2

All of the following are associated with nucleic acid structure EXCEPT

A) ribose.
B) hydrogen bonds.
C) uracil.
D) ionic bonds.
E) phosphate.

Answer 2

D

Question 3

Which of the following is involved in translation?

A) rRNA
B) tRNA
C) mRNA
D) both mRNA and tRNA
E) mRNA, rRNA and tRNA are all involved.

Answer 3

E

Question 4

Which of the following statements regarding eukaryotic transcription is FALSE?

A) Transcription occurs in the nucleus, mitochondria, and chloroplasts (if present).
B) Multiple transcription factors are required.
C) There are four different RNA polymerases.
D) Multiple elongation factors are required.
E) A guanine is added to the 3 end, and a poly-A tail is added to the 5 end of the mRNA transcript.

Question 5

Which of the following statements is true of bacterial plasmids?

A) They are found in the nucleoid.
B) They can replicate autonomously.
C) They carry genes for essential metabolic functions.
D) They are small circular DNA molecules.
E) They are small circular DNA molecules that can replicate autonomously.

Question 6

Which of the following types of plasmids allows a bacterial cell to kill its competitors?

A) virulence factors
B) fertility factors
C) bacteriocin factors
D) resistance factors
E) cryptic plasmids

Question 7

The AUG codon functions in coding for the amino acid methionine and as a

A) termination signal.
B) start signal.
C) "wobble" codon.
D) marker for introns.
E) recognition site for RNA polymerase.

Question 8

Which of the following processes is involved in the "central dogma" of genetics?

A) translation
B) transcription
C) DNA replication
D) transcription and translation
E) DNA replication and translation

Question 9

Which of the following is found at the 5 end of a DNA strand?

A) a phosphate group
B) a hydrogen bond
C) a hydroxyl group
D) histones
E) a methyl group

Question 10

A charged tRNA first enters the ribosomal __________ site and then moves into the __________ site.

A) A, E
B) P, A
C) P, E
D) A, P
E) E, A

Question 11

Semiconservative DNA replication means that

A) each daughter DNA molecule is composed of one original strand and one new strand.
B) nucleotides are constantly being recycled as cells make DNA.
C) the cell can proofread its newly synthesized DNA only part of the time.
D) the sequence of a DNA molecule is preserved as it is being replicated.
E) each strand of a double-stranded DNA molecule is replicated differently.

Question 12

The proofreading function of DNA polymerase III results in an error rate of __________ during DNA replication.

A) 1 error in 1,000 bases
B) 1 error in 100,000 bases
C) 1 error in 1 million bases
D) 1 error in 10 million bases
E) 1 error in 10 billion bases

Question 13

Which of the following must be removed from a eukaryotic mRNA molecule before it can be translated?

A) promoter
B) exon
C) intron
D) anticodon
E) codon

Question 14

A codon is a particular combination of three nucleotides. Therefore, there are __________ possible combinations of the nucleotides A, C, G, and T.

A) 16
B) 4
C) 12
D) 64
E) 32

Question 15

Which of the following is a characteristic shared by DNA and RNA polymerases?

A) efficiency of proofreading
B) type of nucleotides used
C) direction of polymerization
D) speed
E) dependence on helicase

Question 16

Which of the following is NOT involved the packaging of eukaryotic chromosomes?

A) nucleosomes
B) histones
C) heterochromatin
D) euchromatin
E) Okazaki fragments

Question 17

DNA helicases

A) break hydrogen bonds between complementary nucleotides.
B) synthesize short DNA molecules important for the function of DNA polymerase.
C) seal gaps between DNA fragments.
D) proofread DNA molecules.
E) assist in recognition of promoters during transcription.

Question 18

Which of the following is the strongest base pair?

A) guanine-cytosine
B) adenine-uracil
C) adenine-thymine
D) guanine-thymine
E) both adenine-uracil and adenine-thymine

Question 19

Which of the following statements concerning transcription in bacteria is FALSE?

A) It occurs in the nucleoid region.
B) Sigma factors are parts of RNA polymerase that recognize promoter regions.
C) The same RNA polymerase transcribes primer RNA, mRNA, tRNA, and rRNA.
D) Termination is either self-induced or due to the presence of Rho protein.
E) There are a variety of sigma factors that affect transcription.

Question 20

The bacterial chromosome is

A) usually circular.
B) found in a nucleoid.
C) found in a nucleus.
D) both circular and found in a nucleoid.
E) both circular and found in a nucleus.

Question 21

Which of the following is NOT involved in the regulation of the lac operon?

A) an inducer
B) a repressor protein
C) an iRNA
D) glucose
E) cyclic AMP

Question 22

Codons are recognized during

A) translation.
B) transcription.
C) base excision.
D) DNA replication.
E) transduction.

Question 23

If the codon AAA is changed to AAG, it still codes for the amino acid lysine; this is an example of a

A) silent mutation.
B) nonsense mutation.
C) frameshift mutation.
D) gross mutation.
E) missense mutation.

Question 24

Frederick Griffith discovered

A) transformation.
B) transposons.
C) the lac operon.
D) DNA.
E) conjugation.

Question 25

__________ is initiated at sequences called origins.

A) DNA replication
B) Translation
C) Splicing
D) Transcription
E) Transposition

Question 26

The process of __________ requires the activity of DNA ligase.

A) translation
B) capping
C) transcription
D) DNA replication
E) transduction

Question 27

Which of the following is a DNA repair enzyme activated by visible light?

A) transposase
B) DNA photolyase
C) bacteriocin
D) DNA ligase
E) primase

Question 28

Which of the following are considered to be frameshift mutations?

A) insertions
B) inversions
C) deletions
D) both inversion and insertions
E) both deletions and insertions

Question 29

Genes are active in a region of the eukaryotic chromosome called

A) heterochromatin.
B) the histone.
C) the nucleoid.
D) the plasmid.
E) euchromatin.

Question 30

The Ames test proves that a chemical is

A) carcinogenic.
B) carcinogenic in Salmonella.
C) mutagenic in Salmonella.
D) carcinogenic in humans.
E) mutagenic in humans.

Question 31

In conjugation, F⁺ cells

A) serve as recipient cells.
B) contain an F plasmid.
C) do not have conjugation pili.
D) can transfer DNA only to other F⁺ cells.
E) contain "jumping genes."

Question 32

RNA polymerase is primarily responsible for

A) DNA replication.
B) translation.
C) transcription.
D) transformation.
E) polyadenylation.

Question 33

Inducible operons

A) are active in the presence of a repressor.
B) are generally anabolic pathways.
C) are normally active.
D) usually require an activator to be transcribed.
E) usually require a repressor to be transcribed.

Question 34

The energy required for DNA replication comes from

A) DNA polymerase.
B) triphosphate deoxyribonucleotides.
C) DNA ligase.
D) RNA primer.
E) the leading strand.

Question 35

Which of the following causes mutations by creating thymine dimers?

A) nucleotide analogs
B) nitrous acid
C) ultraviolet light
D) benzopyrene
E) gamma rays

Question 36

The horizontal transfer process known as transduction

A) involves a virus.
B) requires a pilus.
C) requires a cell to be "competent."
D) requires a plasmid.
E) involves a mutagen.

Question 37

Another term for the palindromic sequence found at the ends of transposons is a(n)

A) complex transposon.
B) bacteriophage.
C) insertion sequence.
D) inverted repeat.
E) transposase.

Question 38

DNA damage caused by ethidium bromide results in __________ mutations.

A) insertion
B) substitution
C) deletion
D) both inversion and insertion
E) both insertion and deletion

Question 39

Which of the following is characteristic of prokaryotic genomes but not eukaryotic genomes?

A) histones
B) circular chromosomes
C) linear chromosomes
D) enclosed in a nuclear membrane
E) typically consist of a few to several chromosomes

Question 40

Genetic elements known as promoters are initiation points in the process of

A) DNA replication.
B) transcription.
C) translation.
D) mutation repair.
E) transformation.

Question 41

The structure of DNA explains both its ability to encode genetic information and the way in which it is copied during cell reproduction.

Question 42

Transfer of DNA between cells by viruses is called __________.

Question 43

In generalized transduction, viruses carry random DNA sequences from one cell to another.

Question 44

Bidirectional replication means that each strand of a DNA molecule is replicated in the opposite direction from the other.

Question 45

During __________, the growing polymer is located in the P site.

A) polyadenylation
B) DNA replication
C) mismatch repair
D) transcription
E) translation

Question 46

Most bacteria have a natural ability to take up DNA from their environment.

Question 47

Prokaryotes have one type of DNA polymerase, which is different from that of eukaryotes.

Question 48

DNA polymerase III participates in the dark repair mechanism of DNA mutation repair.

Question 49

Initiation of __________ involves Sigma factor molecules.

A) DNA replication
B) translation
C) transcription
D) splicing
E) termination

Question 50

The phenotype of an organism reflects only part of its genotype.

Question 51

DNA, which is negatively charged, wraps around positively charged histones as part of the packaging of eukaryotic chromosomes.

Question 52

The process of __________ requires participation of tRNA molecules.

A) DNA replication
B) capping
C) transcription
D) translation
E) dark repair

Question 53

The process of __________ is described as semiconservative.

A) translation
B) transcription
C) mismatch repair
D) transformation
E) DNA replication

Question 54

Prokaryotic cells are diploid.

Question 55

The enzyme that removes supercoils generated during DNA replication is __________.

Question 56

A(n) __________ is a mutant organism that has different nutritional requirements from the original wild-type organism.

Question 57

The most common type of mutation is a point mutation.

Question 58

The process of __________ is initiated with the incorporation of fMet.

A) translation
B) transcription
C) capping
D) DNA replication
E) light repair

Question 59

Loosely packed regions of a eukaryotic chromosome are called __________.

Question 60

A(n) __________ is a specific sequence of nucleotides that codes for a protein or an RNA molecule.

Question 61

A mutation that changes the reading frame of a gene is called a __________ mutation.

Question 62

Transfer RNA molecules carrying amino acids initially bind to the ribosome at the __________ site. (Be sure to use capital letters.)

Question 63

Pre-messenger RNA molecules contain both __________ and exons. (Be sure your answer is plural.)

Question 64

The ________ of a transfer RNA molecule is complementary to a codon in a messenger RNA molecule.

Question 65

Discuss some of the consequences of the significant differences in transcription between prokaryotes and eukaryotes.

Question 66

The __________ is the set of genes in the genome of an organism.

Question 67

5-bromouracil mimics the chemical structure of thymine, making it a(n) __________ of thymine.

Question 68

A point mutation can be completely harmless, or it can result in the death of a cell or organism. Explain why these types of mutations can have such varying effects.

Question 69

Compare and contrast the lactose operon with the tryptophan operon.

Question 70

A(n) __________ is a set of prokaryotic genes that are regulated and transcribed as a unit.

Question 71

dATP and dCTP are examples of triphosphate __________, the building blocks of DNA molecules.

Question 72

Describe the various types of nucleic acids that are typically found in cells.

Question 73

Describe the basic similarities and differences between DNA replication and transcription.

Question 74

RNA polymerase initiates transcription by recognizing specific nucleotide sequences called __________.

Question 75

The __________ strand is the DNA strand that is synthesized continuously during DNA replication.