Deck 9: An Introduction to Microbial Genetics

Question 1

Each nucleotide is composed of

A)One phosphate, one nitrogenous base, one sugar
B)One phosphate, one nitrogenous base, two sugars
C)Two phosphates, one nitrogenous base, one sugar
D)Two phosphates, one nitrogenous base, two sugars
E)One phosphate, two nitrogenous bases, one sugar

Answer 1

A

Question 2

Which is incorrect about purines?

A)Only found in DNA, not in RNA
B)Are nitrogenous bases
C)Always paired with a specific pyrimidine
D)Include adenine and guanine
E)Found within nucleotides

Answer 2

A

Question 3

Okazaki fragments are attached to the growing end of the lagging strand by

A)DNA ligase
B)DNA polymerase
C)DNA helicase
D)DNA gyrase
E)Primase

Answer 3

A

Question 4

Among the microorganisms, various genomes can include

A)Chromosomes
B)Plasmids
C)Mitochondrial DNA
D)Chloroplast DNA
E)All of the choices are correct

Question 5

Each _____ is a specific segment of the DNA with the code for production of one functional product.

A)Intron
B)Exon
C)Gene
D)Operator
E)Triplet

Question 6

The enzyme that helps pack DNA into the cell by coiling the DNA into a tight bundle is:

A)DNA ligase
B)DNA polymerase
C)DNA helicase
D)DNA gyrase
E)Primase

Question 7

A nucleosome is a linear chromosome wound around the

A)Nuclear membrane
B)rRNA
C)mRNA
D)Histone
E)Nucleolus

Question 8

DNA polymerase III

A)Is needed for adding nucleotides during mRNA synthesis
B)Synthesizes new DNA only in the 5' to 3' direction
C)Cannot add nucleotides to the lagging strand
D)Synthesizes an RNA primer
E)All of the choices are correct

Question 9

During replication, each parent DNA strand serves as a _____ for synthesis of new DNA strands.

A)Copy point
B)Template
C)Comparison molecule
D)Scaffold
E)Reservoir

Question 10

The _____ is all of the genetic material of a cell.

A)Chromosome
B)Plasmid
C)Prophage
D)Genome
E)Proteome

Question 11

Semiconservative replication refers to

A)Each base bonding at the 1' position of the sugar
B)A purine always bonding to a pyrimidine
C)One helix strand that runs from the 5' to 3' direction and the other strand runs from the 3' to 5' direction
D)An original parent DNA strand and one newly synthesized DNA strand comprising a new DNA molecule
E)None of the choices are correct

Question 12

The expression of genetic traits is the

A)Genome
B)Genotype
C)Proteome
D)Phenotype
E)Proteotype

Question 13

The DNA of microorganisms is made up of subunits called

A)Histones
B)Amino acids
C)Nucleotides
D)mRNA
E)Polymerases

Question 14

The antiparallel arrangement within DNA molecules refers to

A)Each base bonding at the 1' position of the sugar
B)A purine always bonding to a pyrimidine
C)One helix strand that runs from the 5' to 3' direction and the other strand runs from the 3' to 5' direction
D)An original parent DNA strand and one newly synthesized DNA strand comprising a new DNA molecule
E)None of the choices are correct

Question 15

Which of the following is not true of an organism's genotype?

A)Is inherited
B)Are structural genes coding for proteins
C)Are genes coding for RNA
D)Are regulatory genes controlling gene expression
E)Are the expressed traits governed by the genes

Question 16

All of the following pertain to nitrogenous bases except

A)Form pairs by hydrogen bonding
B)Guanine pairs with uracil
C)Adenine pairs with thymine
D)Cytosine and thymine are pyrimidines
E)Allows variation from one nucleotide to another which creates the encoded information

Question 17

Eukaryotic chromosomes differ from prokaryotic chromosomes because only eukaryotes have

A)Histone proteins
B)Chromosomes in a nucleus
C)Several to many chromosomes
D)Elongated, not circular, chromosomes
E)All of the choices are correct

Question 18

Base pairs in DNA are held together by _____ bonds.

A)Peptide
B)Non polar covalent
C)Polar covalent
D)Hydrogen
E)Sulfhydryl

Question 19

Structural genes code for

A)Ribosomal RNA molecules
B)Transfer RNA molecules
C)Cellular proteins
D)Gene expression elements
E)All of the choices are correct

Question 20

The duplication of a cell's DNA is called

A)Mitosis
B)Replication
C)Transcription
D)Translation
E)Mutation

Question 21

RNA molecules differ from DNA molecules because only RNA

A)Has ribose
B)Has uracil
C)Is typically one strand of nucleotides
D)Does not have thymine
E)All of the choices are correct

Question 22

If a codon for alanine is GCA, then the anticodon is

A)GCA
B)CGT
C)ACG
D)CGU
E)UGC

Question 23

DNA gyrase

A)Unwinds DNA
B)Supercoils DNA
C)Cleaves DNA
D)Joins free DNA ends
E)None of the choices are correct

Question 24

RNA polymerase binds to the

A)Start codon
B)Termination sequence
C)Regulation sequence
D)Promoter sequence
E)None of the choices are correct

Question 25

Which of the following is incorrect about transfer RNA?

A)Has a bottom hairpin loop with an anticodon
B)An anticodon is complementary to a codon
C)Contains a binding site for an amino acid
D)The initiator tRNA that binds to the P site has the anticodon UAC
E)Initiator tRNA in bacteria carries tryptophan

Question 26

Helicase

A)Unwinds DNA
B)Supercoils DNA
C)Unwinds RNA
D)Winds RNA
E)None of the choices are correct

Question 27

All of the following pertain to transcription except

A)Occurs on a ribosome in the cytoplasm
B)Occurs before translation
C)Requires RNA polymerase
D)Requires a template DNA strand
E)Is a process of protein synthesis

Question 28

DNA Polymerase I

A)Removes primers
B)Adds bases to new DNA chain
C)Seals DNA gaps
D)Proofreads DNA chain
E)All of the choices are correct

Question 29

A primer of ____ is needed at the origin of nucleotide addition.

A)Polymerase III
B)Polymerase I
C)Helicase
D)RNA
E)DNA

Question 30

The nontranscribed region of DNA to which RNA polymerase binds to nitiate transcription is called the

A)Promoter
B)Operator
C)Operon
D)Exon
E)Intron

Question 31

The following pertain to ribosomes during protein synthesis except

A)Contain codons within their rRNA molecules
B)Participate only in translation
C)Bind to the 5' end of mRNA by their small subunit
D)Use their large subunit to supply enzymes for peptide bonding
E)Shift toward the 3'end of the mRNA strand from one codon to the next

Question 32

The RNA molecules that carry amino acids to the ribosomes during protein synthesis are called

A)Ribosomal RNA
B)Messenger RNA
C)Transfer RNA
D)Primer RNA
E)Ribozymes

Question 33

The site where the old DNA strands separate and new DNA strands will be synthesized is called the

A)Primer
B)Okazaki fragment
C)Template
D)Rolling circle
E)Replication fork

Question 34

Replication of DNA begins at a(n)

A)Guanine-cytosine rich area
B)Uracil-adenine rich area
C)Adenine-thymine rich area
D)Adenine-cytosine rich area
E)Guanine-adenine rich area

Question 35

Groups of three consecutive bases along the DNA of a gene have the code for one

A)Protein
B)Nucleotide
C)Amino acid
D)Purine
E)None of the choices are correct

Question 36

This molecule is synthesized as a copy of a gene on the DNA template strand

A)Ribosomal RNA
B)Messenger RNA
C)Transfer RNA
D)Primer RNA
E)Ribozymes

Question 37

The enzyme that can proofreads replicating DNA, detects incorrect bases, excises them, and correctly replaces them is

A)DNA ligase
B)DNA polymerase
C)DNA helicase
D)DNA gyrase
E)Primase

Question 38

DNA Polymerase III

A)Synthesizes primer
B)Removes primer
C)Joins Okazaki fragments
D)Unzips the DNA helix
E)Proofreads new DNA

Question 39

A permanent, inheritable change in the genetic information is called a(n)

A)Translation
B)Transcription
C)Mutation
D)Alteration
E)Regeneration

Question 40

The three-base sequence on DNA that codes for an amino acid is called a(n)

A)Codon
B)Exon
C)Anticodon
D)Intron
E)Triplet

Question 41

A mutation that changes a normal codon to a stop codon is called a

A)Point mutation
B)Silent mutation
C)Back mutation
D)Missense mutation
E)Nonsense mutation

Question 42

Synthesis of an inducible enzyme requires

A)Repressor alone bound to operator
B)Substrate bound to repressor
C)Substrate bound to promoter
D)Co repressor and repressor binding to operator
E)None of the choices are correct

Question 43

If the wild type DNA sequence reads THE CAT ATE THE BIG RAT, what type of mutation would change the sequence to THE CAT ATA ETH EBI GRA T?

A)Missense
B)Nonsense
C)Insertion
D)Deletion
E)Silent

Question 44

Which of the following is incorrect about termination codons?

A)Are also called nonsense codons
B)Where the bond between the final tRNA and the growing polypeptide is broken
C)Include AUG
D)Include UAA, UAG, UGA
E)Do not have corresponding tRNA

Question 45

The gene of an operon that codes for a protein repressor is called the

A)Operator
B)Structural locus
C)Regulator
D)Promoter
E)None of the choices are correct

Question 46

Full induction of the lactose operon requires

A)Lactose present
B)Lactose and glucose present
C)Lactose present without glucose
D)Lactose and arabinose present
E)All of the choices induce the lactose operon

Question 47

A frameshift is caused by ______ mutations?

A)Missense and insertion
B)Missense and nonsense
C)Nonsense and deletion
D)Deletion and insertion
E)Insertion and nonsense

Question 48

Split genes

A)Are common in prokaryotes and eukaryotes
B)Only have exons initially transcribed to mRNA
C)Have introns located only at the beginning and end of a coding region
D)Use spliceosomes to excise introns and then join exons
E)All of the choices are correct

Question 49

If the wild type DNA sequence reads THE CAT ATE THE BIG RAT, what type of mutation would change the sequence to THE CAT ATE (stop)?

A)Missense
B)Nonsense
C)Insertion
D)Deletion
E)Silent

Question 50

The most serious type of mutation is a

A)Point mutation
B)Silent mutation
C)Frameshift mutation
D)Back mutation
E)All the choices are equally serious

Question 51

Which is incorrect about inducible operons?

A)Have genes turned off by a buildup of end product
B)Are often for catabolic pathways
C)Are normally turned off
D)Are turned on by the substrate of the enzyme
E)Include the lac operon

Question 52

What type of mutation alters the base, but not the amino acid being coded for?

A)Silent
B)Back
C)Point
D)Nonsense
E)Missense

Question 53

Gene regulation can involve a protein repressor that blocks _____ from initiating transcription.

A)DNA polymerase I
B)DNA polymerase III
C)RNA polymerase
D)mRNA
E)rRNA

Question 54

A sequence of bases on a gene that does not code for protein is called a/an

A)Promoter
B)Operator
C)Operon
D)Exon
E)Intron

Question 55

The lactose repressor

A)Is transcribed with the structural lac genes
B)Is activated by binding lactose
C)Is inactivated by binding lactose
D)Requires lactose for its transcription
E)None of the choices are correct

Question 56

If the wild type DNA sequence reads THE CAT ATE THE BIG RAT, what type of mutation would change the sequence to THE CAT ATE THE BAG RAT?

A)Missense
B)Nonsense
C)Insertion
D)Deletion
E)Silent

Question 57

Which of the following is not associated with a prokaryotic ribosome?

A)Is a 70s
B)Has a peptide (P) site
C)Has an exit site
D)Small unit provides the enzymes for making peptide bonds
E)Has an amino acid (A) site

Question 58

A screening system called the _____ test is used for detecting chemicals with carcinogenic potential.

A)Koch
B)Ames
C)Mutation
D)Cancer
E)Iowa

Question 59

Repressible operons require that _____ bind to the repressor protein before it can bind to the operator.

A)The product
B)A cofactor
C)A coenzyme
D)The substrate
E)The reactant

Question 60

Synthesis of a repressible enzyme is inhibited by

A)Repressor alone bound to operator
B)Substrate bound to repressor
C)Substrate bound to promoter
D)Corepressor and repressor binding to operator
E)None of the choices are correct

Question 61

The smallest unit of heredity is a chromosome.

Question 62

Which of the following is not true of conjugation?

A)Involves direct contact between cells
B)Transfers genes for drug resistance
C)Transfers genes for enzymes and adherence molecules
D)Transfers genes for a polysaccharide capsule
E)The donor retains a copy of the transferred genes

Question 63

The transfer of DNA fragments from a dead cell to a live, competent recipient cell that results in a changed recipient cell is

A)Transduction
B)Conjugation
C)Transformation
D)Transmission
E)Mitosis

Question 64

The process in which mutations are removed and the correct bases added is called

A)Transduction
B)Excision repair
C)Frameshift
D)Back-mutation
E)Transformation

Question 65

Of the following list, which antibiotics affect protein synthesis?

A)penicillin
B)tetracycline
C)chloramphenicol
D)ciprofloxacin
E)Both B and C

Question 66

Hfr transfer involves all of the following except

A)Gene integration into the bacterial chromosome
B)Plasmid gene transfer
C)F factor is part of the F+ donor chromosome
D)High frequency transfer
E)A pilus connection between F+ and F- cells

Question 67

Transcription occurs in the nucleus or at the nucleoid.

Question 68

Which of the following additions have been made to principles of the central dogma of biology?

A)DNA information cannot be converted into RNA information
B)Protein information can be converted into DNA information
C)RNA can be used to regulate gene function
D)DNA codes for proteins
E)All of these

Question 69

Bacterial conjugation involves

A)Bacteriophage carrying donor DNA to the recipient cell
B)A donor cell with a plasmid that synthesizes a pilus
C)Naked DNA fragments from a lysed donor cell are taken up by a recipient cell
D)New progeny cells with genes from two parent bacterial cells
E)None of the choices are correct

Question 70

The jumping of a gene from one location to another is done by

A)Conjugation
B)Transposons
C)Transformation
D)Transduction
E)Transmission

Question 71

Which cell can transfer the most DNA?

A)F⁺ cell
B)F^- cell
C)Hfr cell
D)R cell
E)B cell

Question 72

Which of the following is not true of transposons?

A)Can change pigmentation
B)Can replace damaged DNA
C)Can transfer drug resistance
D)Can change the genome
E)Are always part of plasmids

Question 73

DNA polymerase can only add new nucleotides to the old 3' DNA end.

Question 74

Introns have no detectable functions.

Question 75

Which of the following is not a type of bacterial DNA recombination?

A)Transformation
B)Conjugation
C)Mitosis
D)Transduction
E)None of the above

Question 76

In bacteria, initiator tRNA carries formyl methionine.

Question 77

The development of virulent, toxin-producing bacterial strains due to the presence of a temperate phage can occur in

A)Bacterial conjugation
B)Transformation
C)Generalized transduction
D)Specialized transduction
E)All of the choices are correct

Question 78

In Griffith's experiments with Streptococcus pneumoniae, rough non-encapsulated Streptococci were converted into smooth encapsulated Streptococci in the presence of the heat- killed smooth encapsulated Streptococci.What is the term that describes this process?

A)transduction
B)conjugation
C)transformation
D)cloning

Question 79

DNA replication proceeds in one direction around the bacterial chromosome.

Question 80

A bacteriophage transfers DNA of the previous host to the current host.This is an example of

A)Conjugation
B)Generalized transduction
C)Specialized transduction
D)Creation of an Hfr cell
E)None of the choices are correct