Deck 9: Microbial Genetics

Question 1

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.

Answer 1

B

Question 2

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 that runs from the 3' to 5' direction.
D)an original parent DNA strand and one newly synthesized DNA strand comprising a new DNA molecule.

Answer 2

D

Question 3

A _____ is a specific segment of DNA that codes for the production of one functional product.

A)intron
B)exon
C)gene
D)operator
E)triplet

Answer 3

C

Question 4

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 5

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 6

The duplication of a cell's DNA is called

A)mitosis.
B)replication.
C)transcription.
D)translation.
E)mutation.

Question 7

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 8

Base pairs in DNA are held together by _____ bonds.

A)peptide
B)nonpolar covalent
C)polar covalent
D)hydrogen
E)sulfhydryl

Question 9

A nucleosome is a linear chromosome wound around the

A)nuclear membrane.
B)rRNA.
C)mRNA.
D)histone.
E)nucleolus.

Question 10

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.

Question 11

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

Question 12

The expression of genetic traits is referred to as the organism's

A)genome.
B)genotype.
C)proteome.
D)phenotype.
E)proteotype.

Question 13

Each nucleotide is composed of

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

Question 14

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

A)chromosome
B)plasmid
C)prophage
D)genome
E)proteome

Question 15

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 16

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.

Question 17

Structural genes code for

A)ribosomal RNA molecules.
B)transfer RNA molecules.
C)cellular proteins.
D)gene expression elements.

Question 18

Microorganisms exhibit genomes contained on

A)chromosomes.
B)plasmids.
C)mitochondrial DNA.
D)chloroplast DNA.
E)All of the choices are correct depending on the type of microorganism observed.

Question 19

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 20

The DNA of an organism is made up of subunits called

A)histones.
B)amino acids.
C)nucleotides.
D)mRNA.
E)polymerases.

Question 21

Replication of DNA begins at a/n ___ rich area.

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

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

Which of the following is not a type of microRNA?

A)tRNA
B)miRNA
C)antisense RNA
D)riboswitch
E)siRNA

Question 24

RNA polymerase binds to the

A)start codon.
B)termination sequence.
C)regulation sequence.
D)promoter sequence.

Question 25

The enzyme that can proofread replicating DNA,detect incorrect bases,excise them,and correctly replace them is

A)DNA ligase.
B)DNA polymerase.
C)DNA helicase.
D)DNA gyrase.
E)primase.

Question 26

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

A)promoter.
B)operator.
C)operon.
D)exon.
E)intron.

Question 27

DNA Polymerase III

A)synthesizes primer.
B)removes primer.
C)joins Okazaki fragments.
D)unzips the DNA helix.
E)proofreads new DNA.

Question 28

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

A)translation.
B)transcription.
C)mutation.
D)alteration.
E)regeneration.

Question 29

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 30

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 31

This molecule is translated into an amino acid sequence:

A)ribosomal RNA
B)messenger RNA
C)transfer RNA
D)primer RNA
E)ribozymes

Question 32

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.

Question 33

Helicase

A)unwinds DNA.
B)supercoils DNA.
C)unwinds RNA.
D)winds RNA.

Question 34

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 35

DNA gyrase

A)unwinds DNA.
B)supercoils DNA.
C)cleaves DNA.
D)joins free DNA ends.

Question 36

Which of the following is incorrect about transfer RNA?

A)has a bottom hairpin loop with an anticodon
B)has an anticodon that 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 37

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 38

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

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

Question 39

DNA Polymerase I

A)removes primers.
B)adds bases to new DNA chain.
C)seals DNA gaps.
D)proofreads DNA chain.

Question 40

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)a process used in the synthesis of protein.

Question 41

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 towards the 3' direction along the mRNA strand from one codon to the next.

Question 42

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

A)operator.
B)structural locus.
C)regulator.
D)promoter.

Question 43

Repressible operons require that _____ binds 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 44

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)are acted upon by spliceosomes to excise introns and then join exons.

Question 45

The most serious type of mutation is a ___ mutation.

A)point
B)silent
C)frameshift
D)back

Question 46

Which is incorrect about inducible operons?

A)have genes turned off by a buildup of end product
B)are often for use in catabolic pathways
C)are normally turned off
D)are turned on by the substrate of the enzyme
E)include the lac operon

Question 47

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 polymerase is broken
C)include AUG
D)include UAA,UAG,and UGA
E)do not have corresponding tRNA

Question 48

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.

Question 49

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

A)point
B)silent
C)back
D)missense
E)nonsense

Question 50

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 51

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 52

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.

Question 53

A sequence of bases within a gene that does not code for protein is called a/n

A)promoter.
B)operator.
C)operon.
D)exon.
E)intron.

Question 54

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.

Question 55

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 56

Synthesis of an inducible enzyme requires

A)repressor alone bound to operator.
B)substrate bound to repressor.
C)substrate bound to promoter.
D)corepressor and repressor binding to operator.

Question 57

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)point
B)nonsense
C)insertion
D)deletion
E)silent

Question 58

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

A)has a 70s subunit
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 59

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 60

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 61

Transcription occurs within the nucleus or at the nucleoid.

Question 62

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

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

Question 63

A bacteriophage transfers a random fragment of 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.

Question 64

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

A)transduction.
B)conjugation.
C)transformation.
D)transmission.
E)mitosis.

Question 65

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 taken up by a recipient cell.
D)new progeny cells with genes from two parent bacterial cells.

Question 66

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

A)bacterial conjugation.
B)transformation.
C)generalized transduction.
D)specialized transduction.

Question 67

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 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.

Question 69

Which cell can transfer the most DNA?

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

Question 70

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 71

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

Question 72

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

A)conjugation.
B)transposons.
C)transformation.
D)transduction.
E)transmission.

Question 73

DNA replication proceeds in one direction around the bacterial chromosome.

Question 74

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)involves the action of bacteriophage
E)the donor retains a copy of the transferred genes

Question 75

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 76

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 77

The smallest unit of heredity is a chromosome.

Question 78

In bacteria,initiator tRNA carries formyl methionine.

Question 79

Of the following list,which antibiotics affect protein synthesis?

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

Question 80

In Griffith's experiments with Streptococcus pneumoniae,rough nonencapsulated Streptococci were converted into smooth encapsulated Streptococci in the presence of the heat-killed smooth encapsulated Streptococci.Which microbial process had Griffith identified?

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